Technical Field

The present invention relates to an apparatus comprising an interface to be operable with an antenna and a tuning element to be operable for adjusting an impedance of the interface to match with the impedance of the antenna with respect to a defined frequency range. The invention further relates to a method and a computer program for adjusting an impedance of the interface to match with the impedance of the antenna with respect to a defined frequency range.

Background Information This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.

A modern radio telecommunication environment is very diverse with the use of numerous radio communication schemes, both standard and nonstandard. User devices may be equipped with capabilities to communicate through multiple different radio communication schemes, e.g. GSM, GPRS/EDGE, Bluetooth, WLAN, UMTS and its evolution versions HSDPA, LTE and LTE-A. Additionally, concepts like cognitive radio or software-defined radio (SDR) may be implemented in the user devices in the future. Cognitive radio is a general concept to denote radio devices that are able to sense a radio environment and to select a radio communication scheme and radio communication parameters that may be the most suitable for the sensed radio environment.

In a mobile transceiver a front-end module (FEM) provides means to connect one or more antennas to multiple system transceiver engines. Switches and filters may provide some frequency selectivity with connected wide/multiband antennas. When more and more systems are to be added to the mobile devices the loss and cost penalty of current solutions may increase rapidly to the point when the current way may not be applicable. Summary

Some embodiments provide tunable impedance at a front end of a receiver to match the front end with the antenna impedance. Some embodiments utilize transferred impedance phenomena where a base band or a low frequency impedance is visible at the radio frequency due to mixing of an impedance with a timing signal.

Another aspect of the invention is to use offset biasing in a balanced mixer. Generally, in real clocking signals there is some finite rise and fall time and by adjusting the biases separately one can fine tune the exact switching time of the mixer. The switching instant is related to the threshold of the switching element of the balanced mixer. This can be used to compensate possible errors in clock timing or one can use offsetting for operation/filtering optimization to define a reception frequency with respect to the applied local oscillator signal. Automatic control loop can be applied since the gain/frequency of reception can be affected by voltage tuning.

According to a first aspect of the invention, there is provided an apparatus comprising:

an interface to be operable with an antenna;

a tuning element to be operable for adjusting an impedance of the interface to match with the impedance of the antenna with respect to a defined frequency range; the tuning element comprising at least one input for receiving at least one timing signal for tuning the impedance. According to a second aspect of the invention, there is provided a method comprising:

interfacing with an antenna by an interface;

adjusting an impedance of the interface to match with the impedance of the antenna with respect to a defined frequency range;

receiving at least one timing signal for tuning the impedance. According to a third aspect of the invention, there is provided an apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to:

interface with an antenna by an interface;

adjust an impedance of the interface to match with the impedance of the antenna with respect to a defined frequency range;

receive at least one timing signal for tuning the impedance.

According to a fourth aspect of the invention, there is provided a computer program product including one or more sequences of one or more instructions which, when executed by one or more processors, cause an apparatus to:

interface with an antenna by an interface;

adjust an impedance of the interface to match with the impedance of the antenna with respect to a defined frequency range;

receive at least one timing signal for tuning the impedance.

According to a fifth aspect of the invention, there is provided an apparatus comprising

means for interfacing with an antenna;

means for adjusting an impedance of the means for interfacing to match with the impedance of the antenna with respect to a defined frequency range;

means for receiving at least one timing signal for tuning the impedance.

Description of the Drawings

Figure 1 shows a block diagram of an apparatus according to an example embodiment;

Figure 2 shows an apparatus according to an example embodiment;

Figure 3 shows an example of an arrangement for wireless communication comprising a plurality of apparatuses, networks and network elements; Figure 4a shows a block diagram of RF and IF elements of a receiver according to an example embodiment;

Figure 4b shows a block diagram of another embodiment in which a tuning element is provided for both a receiver and a transmitter; Figure 5a shows schematically a structure of an impedance tuning element for the receiver according to an embodiment;

Figure 5b shows schematically a structure of an impedance tuning element for the receiver according to another embodiment;

Figure 5c shows schematically a structure of an impedance tuning element for the receiver according to a third embodiment;

Figure 5d shows schematically a structure of an impedance tuning element for the receiver according to a fourth embodiment;

Figure 6a shows schematically some details of a front end of the receiver according to an embodiment;

Figure 6b shows schematically the operation of the front end of Figure 6a in a first operating phase;

Figure 6c shows schematically the operation of the front end of Figure 6a in a second operating phase;

Figure 7 shows a high level flow chart of an embodiment of a method of adjusting the input impedance of the front end;

Figures 8a and 8b illustrate simulation results of the gain of the front end of an example embodiment;

Figure 8c illustrates an example of input timing signals for the impedance matching element; and

Figures 9a— 9d illustrate some examples of effects of change in some parameters of the impedance matching element.

Detailed Description of some example Embodiments

The following embodiments are exemplary. Although the specification may refer to "an", "one", or "some" embodiment(s) in several locations, this does not necessarily mean that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.

Figure 4a shows a block diagram of radio frequency (RF) and intermediate frequency (IF) elements of a receiver 100 according to an example embodiment. The receiver converts a received radio signal first to the intermediate frequency and then to a baseband. In some other embodiments the intermediate frequency part is not needed wherein such receivers, which may also be called as direct-conversion receivers, convert a received radio signal directly to the baseband. In the example embodiment of Figure 4a, the receiver comprises an antenna 102 for receiving RF signals. The antenna 102 is connected with an impedance tuning element 104. The connection between the antenna 102 and the impedance tuning element 104 may be called as an interface for an antenna, for example. The connection may be implemented by using a balun or other element which can be used to create a differential RF signal for the impedance tuning element 104. The impedance tuning element 104 may be used to tune the resonance with the impedance of the antenna and the impedance of the front end of the receiver at the frequency range. The impedance tuning element 104 is also provided with timing signals TP_P1 , TP_P2, which may be formed by a timing element 124 on the basis of a local oscillator signal 142 from a local oscillator 122. The timing element 124 may form two or more timing signals TP_P1 , TP_P2, e.g. four timing signals, and possibly delay one or more of the timing signals so that a mixer in the impedance tuning element 104 may provide a proper transferred impedance function. The output of the impedance tuning element 104 is connected to a first amplifier 106. The first amplifier 2 may be a low-noise amplifier (LNA) or another kind of amplifier suitable for amplifying RF signals. The amplified RF signals may then be filtered by a first bandpass filter 108 to eliminate or attenuate signals which are outside the desired frequency range of the RF signals. The RF signals may then be converted to intermediate signals (IF) or directly to bandbass signals by mixing the RF signals with other signals LO_0, LO_90, LO_180, LO_270 from the same local oscillator 122 or from another local oscillator. The bandbass signals may then be amplified by a second amplifier 1 12, low pass filtered by a lowpass filter 1 14 and again amplified by the third amplifier 1 16. The bandpass signals, which can be regarded as analogue signals at the output of the third amplifier, may be converted to digital representations (e.g. samples) by an analogue-to-digital converter 1 18 so that the signals can be digitally processed in further processing steps. The further processing steps are not described in more detail here but may comprise control signal processing such as call control processing, audio signal processing, video signal processing, etc.

In some embodiments the timing signals TP_P1 , TP_P2 may be derived from more than one local oscillator LO signal. For example a multicarrier reception may utilize this scenario.

The timing element(s) 124, 140 may perform some processing on the basis of the local oscillator signal 142. For example, they may set the frequency of the timing signals TP_P1 , TP_P2 so that the tinning signals TP_P1 , TP_P2 may have a different frequency compared to the local oscillator signal 142. In addition to or instead of the frequency variation a duty cycle may be set to a desired value and/or variated or adjusted when appropriate, the pulse width of the timing signals TP_P1 , TP_P2 may be tuned, the phase of the timing signals TP_P1 , TP_P2 may be shifted or set to a desired phase or phase difference between the timing signals may be set and adjusted, etc.

It should be noted here that in some embodiments the baseband signals may include two quadrature phase signals I (ln-phase) and Q (Quadrature phase), wherein the baseband section 1 12— 1 18 may include separate signal processing paths for these two signals. In that case the local oscillator 122 would provide four local oscillator signals LO_0, LO_90, LO_180, LO_270 having different phase shifts (i.e. 0 degrees, 90 degrees, 180 degrees and 270 degrees).

Figure 4a also depicts a part of a transmitter of the apparatus. A signal to be transmitted is input to the mixer 130 of the transmitter in which the signal is mixed with the local oscillator signal from the local oscillator 122. The mixing result is amplified by an amplifier 132 and band bass filtered by the band bass filter 134 so that the signals at the correct transmitting frequency are connected to the transmitting antenna 136. The transmitting antenna may be a separate antenna or the same antenna than the receiving antenna 102.

In some embodiments the impedance tuning element 104 may be implemented in the transmitter as well to match the impedance of the antenna 136 and the impedance of the front end of the transmitter at the frequency range. In some embodiments the tuning element may be the same tuning element than the impedance tuning element 104 of the receiver front end or separate impedance tuning elements may be provided for the receiver and the transmitter. Also the antenna 102, 136 may be common with the receiver and the transmitter or separate antennas 102, 136 may be provided for the receiver and the transmitter. In some embodiments it may also be possible that the impedance tuning element is only implemented in the transmitter.

Figure 4b illustrates an example of a transceiver in which both the receiver and the transmitter are provided with the impedance tuning element 104, 138, respectively. In this example embodiment the impedance tuning element 138 of the transmitter is provided with tuning signals by a second timing element 140 which receives a local oscillator signal from the receiver part. However, in some embodiments the same local oscillator signal 142 may be used by both the first timing element 124 and the second timing element 140 to generate timing signals for the impedance tuning elements 104, 138. In some other embodiments it may be possible to use the same timing element 124 to generate timing signals for both impedance tuning elements 104, 138.

In the following the operation of the impedance tuning element 104 will be described in more detail with reference to figures 5a and 6a. Figure 5a illustrates a simplified circuitry of the impedance tuning element 104 according to an example embodiment. The impedance tuning element 104 may comprise a mixer section formed of switching elements 202, 204, 206 and 208. The switching elements 202, 204, 206, 208 may be MOSFET-transistors or other kinds of transistors or diodes which enable controlling the signal path between the input and the output of the impedance tuning element 104 under the control of the timing signals TP_P1 , TP_P2. In this embodiment the switching elements 202, 204, 206, 208 are connected so that two pairs of switching elements are formed so that the control inputs of each switching element of the pair are connected together. For example in Figure 5a, the switching elements 202 and 208 form a first pair and the switching elements 204 and 206 form a second pair of control elements. The first timing signal TP_P1 is provided to the control inputs of the first pair and the second timing signal TP_P2 is provided to the control inputs of the second pair.

When a MOSFET-transistor or other kinds of FET-transistor is used as the switching element, the control element is the gate or gates of the transistor.

The impedance tuning element 104 further comprises a first impedance 222 and a second impedance 224. The first impedance 222 is connected between a first RF input 210 and a first output 214, and the second impedance 224 is connected between a second RF input 212 and the second output 216. Hence, the first impedance 222 and the second impedance 224 are effectively in series to the RF signals and in parallel to the timing signals TP_P1 , TP_P2.

In this example embodiment the antenna 102 is inductive antenna, wherein the first impedance 222 and the second impedance 224 are capacitive impedances, such as capacitors, but if the antenna is a capacitive antenna, the first impedance 222 and the second impedance 224 would comprise inductive impedances such as coils. However, in practice, purely capacitive and purely inductive impedances may not exist wherein the impedance of any capacitor may also have an inductive and a resistive component, and respectively, any coil may also have a capacitive and a resistive component.

In some embodiments the interface between the antenna and the impedance tuning element 104 need not be a differential connection but may be implemented as a single connection between the antenna and the impedance tuning element 104. In such a case the impedance tuning element 104 may comprise one impedance 222, which is connected between a first RF input 210 and a first output 214 and the second impedance 224 may not be needed.

Figure 5b illustrates a simplified circuitry of the impedance tuning element 104 according to another example embodiment. The impedance tuning element 104 is mostly similar to the impedance tuning element 104 of Figure 5a except that the inputs 210, 212 are provided with another impedances 226, 228, respectively. Hence, the combination of the impedances 222 and 226 as well as the combination of the impedances 224 and 228 may be used for the impedance matching purposes. The impedances 226 and 228 may comprise capacitive and/or inductive impedances such as capacitors and/or coils.

Figure 5c illustrates a simplified circuitry of the impedance tuning element 104 according to a third example embodiment. In this embodiment there are four timing inputs 218, 220, 230, 232 for providing four separate timing signals for the impedance tuning element 104. In this embodiment the four timing signals may be generated in such a way that they may have a 25/75 pulse ratio, i.e. the duty cycle is 0.25, i.e. they are approximately 25% on of the time (and off about 75% of the time) and that they each have about 90 degrees phase difference. In other words, in some embodiments only one timing signal is on at a time.

Figure 5d illustrates a simplified circuitry of the impedance tuning element 104 according to a fourth example embodiment. In this embodiment two impedance tuning elements are connected in parallel to each other. In this example embodiment the impedance tuning elements are similar to the impedance tuning elements of Figure 5b but also other kinds of tuning elements may be used in the parallel construction. The parallel construction of tuning elements may be provided with twice the number of timing signals compared to the situation in which only one tuning element is used. In this example the timing signals 218, 220, 230, 232 may be similar to the timing signals of the embodiment of Figure 5c or they may be different from that. An example of the control section of the impedance tuning element 104 is depicted in Figure 6a. The control logic 1 10 provides a local oscillator control signal 312 to control the operation of the local oscillator 122 so that it creates the local oscillator signal to be input to the timing element 124 for forming the first timing signal 308 (TP_P1 ) and the second timing signal 310 (TP_P2) in such a way that they may have a 25/75 pulse ratio i.e. they are on approximately 25% of the time (and off about 75% of the time) and that they have about 90 degrees phase difference. Examples of such signals are depicted in Figure 8c. In the example of Figure 8c the phase of the first timing signal 308 may be ahead of the second timing signal 310. The timing signals 308, 310 may be connected to the timing inputs of the tuning element 104 e.g. by the capacitors 302, 304 or by some other appropriate means.

The pulse ratio need not be about 25/75 but may be different from that. In some situations it may be possible to adjust the pulse ratio for the impedance matching purposes. It may also be possible that the pulse ratios of different timing signals are not the same but may differ from each other.

Figure 6b shows schematically the operation of the front end of Figure 6a when the first timing signal TP_P1 is at a level which activates the first pair of switching elements and the second timing signal TP_P2 is at a level which does not activate the second pair of switching elements. Respectively, Figure 6c shows schematically the operation of the front end of Figure 6a when the second timing signal TP_P2 is at a level which activates the second pair of switching elements and the first timing signal TP_P1 is at a level which does not activate the first pair of switching elements. The dotted lines illustrate those parts of the circuitry which are inactive.

The control logic 1 10 may also provide a bias control signal 314 to control a bias voltage element 306. The purpose of the bias voltage element 306 is to add some bias voltage to the timing signals 308, 310. This adjustment of the bias voltage may affect the operation of the switching elements of the mixer in the impedance tuning element 104. The timing signals have finite rising and falling times as can be seen from the example signals depicted in Figure 8c. The switching elements change state (i.e. they are set to the on or to the off state) at certain voltage levels. Hence, by adjusting the bias voltage the actual voltage at the control inputs of the switching elements is also adjusted and the change of the state of the switching elements may also occur earlier or later, depending on the level and polarity of the bias voltage (positive/negative), compared to the situation in which the bias voltage is not used (i.e. the bias voltage is 0 V). Therefore, the adjustment of the bias voltage either delays or advances the switching moments of the switching elements of the impedance tuning element 104. This can be used to compensate possible errors in the timing of the timing signals or one can use offsetting for operation/filtering optimization. Automatic control loop can be applied since the gain/frequency can be affected by the bias voltage tuning.

The bias voltages may be combined with the timing signals 308, 310 through resistors 316, 318 or by some other appropriate means. In the embodiment of Figure 6a the bias voltage element 306 provides individual bias voltages for each timing signal 308, 310 so that the bias voltage of each timing signal 308, 310 can be separately controlled but in some other embodiments the same bias voltage may be provided for each timing signal 308, 310. In operation of the apparatus in which the receiver 100 is implemented a frequency range may be selected for communication. This is illustrated with block 702 in Figure 7, which shows a high level flow chart of an embodiment of a method of tuning the input impedance of the front end. The frequency range may be selected on the basis of the channel the apparatus is to be communicated. The control logic 1 10 may then select 704 the transmission frequency to be used and sets 706 the frequency of the local oscillator accordingly. For example, the local oscillator frequency may be set at the centre of the frequency range of the selected channel. In many communication systems simultaneous two-way communication (duplex) between two communication devices, such as a wireless terminal and a base station, is enabled in such a way that there is a fixed frequency separation between an uplink channel (from the wireless terminal to the base station) and a downlink channel (from the base station to the wireless terminal). Therefore, the local oscillator signal frequency for the receiver can be achieved from the local oscillator signal of the transmitter by adding or subtracting the difference between uplink and down link channel frequencies. In some communication systems this duplex distance (or duplex separation) is 20 MHz, and in some other communication systems this duplex distance is 80 MHz or 900 kHz or some other frequency, but the present invention is not limited to such communication systems.

The pulse ratio of the first timing signal 308 (TP_P1 ) and the second timing signal 310 (TP_P2) may also be set 708 to a desired pulse ratio, for example to the 25/75 pulse ratio. The bias voltage may also be set 170 to further adjust the impedance and/or the bandwidth of the front end, if necessary.

When the frequency of the local oscillator 122, the pulse ratio and the bias voltage, if necessary, has been set, the impedance present at the baseband is "visible" to the antenna RF due to the conversion by the timing signals TP_P1 , TP_P2. This way the impedance itself may remain the same but the location of the impedance in a frequency range and thus the resonance frequency of the resonance circuit formed by the antenna 102 and the impedance matching element 104 may be changed, which may improve tuning of the impedances and resonance creation at the front end. Means to affect impedance and overall performance (during usage) are the pulse ratio (i.e. on/off clocking time) of the timing signals TP_P1 , TP_P2 and the voltage bias at the control inputs of the switching elements of mixer in the impedance tuning element 104. With these design options antenna impedances may be matched widely and they may be used to change gain / bandwidth and actual RX frequency location in relation to the timing signal. Figures 8a and 8b depict some examples of tuning varieties. Also figures 9a— 9d illustrate some examples of effects of change in some parameters of the impedance matching element 104. In the example of Figure 9a the gain of the impedance matching element 104 is simulated in which the bias voltage has been reduced by 200 mV. In the example of Figure 9b the gain of the impedance matching element 104 is simulated in which the bias voltage has been increased by 200 mV. In the example of Figure 9c the timing delay has been doubled, and in the example of Figure 9d gain of the impedance matching element 104 is simulated in which the bias voltage has been set to 500 mV. Other parameters are not affected and the frequency of the timing signals is 1 .91 GHz. The effects of the bias voltage/delay changes to the gain (frequency response) can be seen from the Figures 9a— 9d.

Because the local oscillator signal generated for the transmitter section may be used to derive the correct timing signals for the receiver there is no need for separate digital controls for that purpose. Furthermore, the impedance tuning element 104 according to some example embodiments has a frequency response in which there is a notch at the frequency of the local oscillator signal of the transmitter wherein the signals transmitted by the transmitter are attenuated by the impedance tuning element 104 so that they do not disturb the operation of the receiver or at least the disturbances are smaller than without the impedance tuning element 104.

By utilising the present invention very wide frequency range may be achieved. The bandwidth, RX location under or over the TX frequency and TX RX separation can be tuned as well as the gain of the selected frequency band. The above description of some example embodiments discusses just impedances for clarity, but impedances mentioned in this description, such as the first impedance 222 and the second impedance 224 as well as the impedances 226 and 228 may be formed as components having an impedance. It should, however, be noted that the term component need not mean an individual component but it may be formed as a part of an electronic circuitry such as an integrated circuit, for example an application specific integrated circuit (ASIC), and/or by using other technologies which may be suitable for producing such an impedance.

Many embodiments of the present invention may be implemented in software defined radios in which the tuning of the front end is at least partially performed by software.

The following describes in further detail suitable apparatus and possible mechanisms for implementing the embodiments of the invention. In this regard reference is first made to Figure 1 which shows a schematic block diagram of an exemplary apparatus or electronic device 50 depicted in Figure 2, which may incorporate a receiver front end according to an embodiment of the invention.

The electronic device 50 may for example be a mobile terminal or user equipment of a wireless communication system. However, it would be appreciated that embodiments of the invention may be implemented within any electronic device or apparatus which may require reception of radio frequency signals.

The apparatus 50 may comprise a housing 30 for incorporating and protecting the device. The apparatus 50 further may comprise a display 32 in the form of a liquid crystal display. In other embodiments of the invention the display may be any suitable display technology suitable to display an image or video. The apparatus 50 may further comprise a keypad 34. In other embodiments of the invention any suitable data or user interface mechanism may be employed. For example the user interface may be implemented as a virtual keyboard or data entry system as part of a touch-sensitive display. The apparatus may comprise a microphone 36 or any suitable audio input which may be a digital or analogue signal input. The apparatus 50 may further comprise an audio output device which in embodiments of the invention may be any one of: an earpiece 38, speaker, or an analogue audio or digital audio output connection. The apparatus 50 may also comprise a battery 40 (or in other embodiments of the invention the device may be powered by any suitable mobile energy device such as solar cell, fuel cell or clockwork generator). The apparatus may further comprise an infrared port 42 for short range line of sight communication to other devices. In other embodiments the apparatus 50 may further comprise any suitable short range communication solution such as for example a Bluetooth wireless connection or a USB/firewire wired connection. The apparatus 50 may comprise a controller 56 or processor for controlling the apparatus 50. The controller 56 may be connected to memory 58 which in embodiments of the invention may store both data and/or may also store instructions for implementation on the controller 56. The controller 56 may further be connected to codec circuitry 54 suitable for carrying out coding and decoding of audio and/or video data or assisting in coding and decoding carried out by the controller 56.

The apparatus 50 may further comprise a card reader 48 and a smart card 46, for example a UICC and UICC reader for providing user information and being suitable for providing authentication information for authentication and authorization of the user at a network.

The apparatus 50 may comprise radio interface circuitry 52 connected to the controller and suitable for generating wireless communication signals for example for communication with a cellular communications network, a wireless communications system or a wireless local area network. The apparatus 50 may further comprise an antenna 44 connected to the radio interface circuitry 52 for transmitting radio frequency signals generated at the radio interface circuitry 52 to other apparatus(es) and for receiving radio frequency signals from other apparatus(es). In some embodiments of the invention, the apparatus 50 comprises a camera capable of recording or detecting imaging. With respect to Figure 3, an example of a system within which embodiments of the present invention can be utilized is shown. The system 10 comprises multiple communication devices which can communicate through one or more networks. The system 10 may comprise any combination of wired or wireless networks including, but not limited to a wireless cellular telephone network (such as a GSM, UMTS, CDMA network etc), a wireless local area network (WLAN) such as defined by any of the IEEE 802.x standards, a Bluetooth personal area network, an Ethernet local area network, a token ring local area network, a wide area network, and the Internet. The system 10 may include both wired and wireless communication devices or apparatus 50 suitable for implementing embodiments of the invention.

For example, the system shown in Figure 3 shows a mobile telephone network 1 1 and a representation of the internet 28. Connectivity to the internet 28 may include, but is not limited to, long range wireless connections, short range wireless connections, and various wired connections including, but not limited to, telephone lines, cable lines, power lines, and similar communication pathways.

The example communication devices shown in the system 10 may include, but are not limited to, an electronic device or apparatus 50, a combination of a personal digital assistant (PDA) and a mobile telephone 14, a PDA 16, an integrated messaging device (IMD) 18, a desktop computer 20, a notebook computer 22. The apparatus 50 may be stationary or mobile when carried by an individual who is moving. The apparatus 50 may also be located in a mode of transport including, but not limited to, a car, a truck, a taxi, a bus, a train, a boat, an airplane, a bicycle, a motorcycle or any similar suitable mode of transport.

Some or further apparatus may send and receive calls and messages and communicate with service providers through a wireless connection 25 to a base station 24. The base station 24 may be connected to a network server 26 that allows communication between the mobile telephone network 1 1 and the internet 28. The system may include additional communication devices and communication devices of various types. The communication devices may communicate using various transmission technologies including, but not limited to, code division multiple access (CDMA), global systems for mobile communications (GSM), universal mobile telecommunications system (UMTS), time divisional multiple access (TDMA), frequency division multiple access (FDMA), transmission control protocol-internet protocol (TCP-IP), short messaging service (SMS), multimedia messaging service (MMS), email, instant messaging service (IMS), Bluetooth, IEEE 802.1 1 and any similar wireless communication technology. A communications device involved in implementing various embodiments of the present invention may communicate using various media including, but not limited to, radio, infrared, laser, cable connections, and any suitable connection. Although the above examples describe embodiments of the invention operating within a transceiver within an electronic device, it would be appreciated that the invention as described below may be implemented as part of any apparatus comprising a receiver and/or a transmitter. Thus, for example, embodiments of the invention may be implemented in a wireless communication device.

Thus, user equipment may comprise a transceiver such as those described in embodiments of the invention above. It shall be appreciated that the term user equipment is intended to cover any suitable type of wireless communication device, such as mobile telephones, portable data processing devices or portable web browsers.

Furthermore elements of a public land mobile network (PLMN) may also comprise transceivers as described above. In general, the various embodiments of the invention may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof. The embodiments of this invention may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Further in this regard it should be noted that any blocks of the logic flow as in the Figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD.

The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multi core processor architecture, as non limiting examples. Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

Programs, such as those provided by Synopsys, Inc. of Mountain View, California and Cadence Design, of San Jose, California automatically route conductors and locate components on a semiconductor chip using well established rules of design as well as libraries of pre stored design modules. Once the design for a semiconductor circuit has been completed, the resultant design, in a standardized electronic format (e.g., Opus, GDSII, or the like) may be transmitted to a semiconductor fabrication facility or "fab" for fabrication.

The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of the exemplary embodiment of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention.

In the following, some examples will be provided.

According to a first example, there is provided an apparatus comprising:

an interface to be operable with an antenna;

a tuning element to be operable for adjusting an impedance of the interface to match with the impedance of the antenna with respect to a defined frequency range; the tuning element comprising at least one input for receiving at least one timing signal for tuning the impedance.

In some embodiments of the apparatus the tuning element comprises at least one component with impedance, the component with impedance being connected between the interface and an output of the tuning element.

In some embodiments of the apparatus the tuning element comprises at least one component with impedance, the component with impedance being connected in series with the interface.

In some embodiments the apparatus comprises:

a first input to provide a first timing signal to the tuning element; and

a second input to provide a second timing signal to the tuning element. In some embodiments the apparatus comprises a bias voltage input for adjusting the level of the at least one timing signal.

In some embodiments the apparatus comprises:

a local oscillator to generate a local oscillator signal for a transmitter; and a timing element to be operable with the local oscillator signal to form the at least one timing signal.

In some embodiments of the apparatus the timing element is operable for adjusting a pulse ratio of the at least one timing signal.

In some embodiments of the apparatus the timing element is operable for delaying the at least one timing signal. In some embodiments of the apparatus the tuning element comprises a mixer.

In some embodiments of the apparatus the mixer is operable for mixing a received radio frequency signal with the at least one timing signal.

In some embodiments of the apparatus the impedance comprises an impedance of a front end of the apparatus. n some embodiments of the apparatus the apparatus is a part of a receiver.

In some embodiments of the apparatus the apparatus is a part of a transmitter.

In some embodiments of the apparatus the apparatus is a part of a wireless communication device.

According to a second example, there is provided a method comprising:

interfacing with an antenna by an interface;

adjusting an impedance of the interface to match with the impedance of the antenna with respect to a defined frequency range;

receiving at least one timing signal for tuning the impedance.

In some embodiments of the method the tuning comprises using at least one component with impedance, the component with impedance being connected between the interface and an output of the tuning element.

In some embodiments of the method the tuning comprises using at least one component with impedance, the component with impedance being connected in series with the interface.

In some embodiments the method comprises:

providing a first timing signal to the tuning element; and

providing a second timing signal to the tuning element. In some embodiments the method comprises providing a bias voltage for adjusting the level of the at least one timing signal. In some embodiments the method comprises:

generating a local oscillator signal for a transmitter; and

forming the at least one timing signal by using the local oscillator signal. In some embodiments the method comprises adjusting a pulse ratio of the at least one timing signal.

In some embodiments the method comprises delaying the at least one timing signal. In some embodiments the method comprises mixing a received radio frequency signal with the at least one timing signal.

In some embodiments the method comprises tuning an impedance of a front end of the apparatus.

In some embodiments the method is performed in a receiver.

In some embodiments the method is performed in a transmitter. In some embodiments the method is performed in a wireless communication device.

According to a third example, there is provided an apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to:

interface with an antenna by an interface;

adjust an impedance of the interface to match with the impedance of the antenna with respect to a defined frequency range;

receive at least one timing signal for tuning the impedance.

In some embodiments of the apparatus said at least one memory stored with code thereon, which when executed by said at least one processor, further causes the apparatus to use at least one component with impedance, the component with impedance being connected between the interface and an output of the tuning element. In some embodiments of the apparatus said at least one memory stored with code thereon, which when executed by said at least one processor, further causes the apparatus to use at least one component with impedance, the component with impedance being connected in series with the interface.

In some embodiments of the apparatus said at least one memory stored with code thereon, which when executed by said at least one processor, further causes the apparatus to:

provide a first timing signal to the tuning element; and

provide a second timing signal to the tuning element.

In some embodiments of the apparatus said at least one memory stored with code thereon, which when executed by said at least one processor, further causes the apparatus to provide a bias voltage for adjusting the level of the at least one timing signal.

In some embodiments of the apparatus said at least one memory stored with code thereon, which when executed by said at least one processor, further causes the apparatus to:

generate a local oscillator signal for a transmitter; and

form the at least one timing signal on the basis of the local oscillator signal.

In some embodiments of the apparatus said at least one memory stored with code thereon, which when executed by said at least one processor, further causes the apparatus to adjust a pulse ratio of the at least one timing signal.

In some embodiments of the apparatus said at least one memory stored with code thereon, which when executed by said at least one processor, further causes the apparatus to delay the at least one timing signal.

In some embodiments of the apparatus said at least one memory stored with code thereon, which when executed by said at least one processor, further causes the apparatus to mix a received radio frequency signal with the at least one timing signal. In some embodiments of the apparatus said at least one memory stored with code thereon, which when executed by said at least one processor, further causes the apparatus to tune an impedance of a front end of the apparatus. According to a fourth example, there is provided a computer program product including one or more sequences of one or more instructions which, when executed by one or more processors, cause an apparatus to:

interface with an antenna by an interface;

adjust an impedance of the interface to match with the impedance of the antenna with respect to a defined frequency range;

receive at least one timing signal for tuning the impedance. In some embodiments the computer program product includes one or more sequences of one or more instructions which, when executed by one or more processors, cause the apparatus to use at least one component with impedance, the component with impedance being connected between the interface and an output of the tuning element.

In some embodiments the computer program product includes one or more sequences of one or more instructions which, when executed by one or more processors, cause the apparatus to use at least one component with impedance, the component with impedance being connected in series with the interface.

In some embodiments the computer program product includes one or more sequences of one or more instructions which, when executed by one or more processors, cause the apparatus to:

provide a first timing signal to the tuning element; and

provide a second timing signal to the tuning element.

In some embodiments the computer program product includes one or more sequences of one or more instructions which, when executed by one or more processors, cause the apparatus to provide a bias voltage for adjusting the level of the at least one timing signal.

In some embodiments the computer program product includes one or more sequences of one or more instructions which, when executed by one or more processors, cause the apparatus to:

generate a local oscillator signal for a transmitter; and

form the at least one timing signal on the basis of the local oscillator signal. In some embodiments the computer program product includes one or more sequences of one or more instructions which, when executed by one or more processors, cause the apparatus to adjust a pulse ratio of the at least one timing signal.

In some embodiments the computer program product includes one or more sequences of one or more instructions which, when executed by one or more processors, cause the apparatus to delay the at least one timing signal.

In some embodiments the computer program product includes one or more sequences of one or more instructions which, when executed by one or more processors, cause the apparatus to mix a received radio frequency signal with the at least one timing signal.

In some embodiments the computer program product includes one or more sequences of one or more instructions which, when executed by one or more processors, cause the apparatus to tune an impedance of a front end of the apparatus.

According to a fifth example, there is provided an apparatus comprising:

means for interfacing with an antenna;

means for adjusting an impedance of the means for interfacing to match with the impedance of the antenna with respect to a defined frequency range;

means for receiving at least one timing signal for tuning the impedance.

In some embodiments of the apparatus the tuning element comprises means for connecting at least one component with impedance between the interface and an output of the tuning element.

In some embodiments of the apparatus the tuning element comprises means connecting at least one component with impedance in series with the interface.

In some embodiments the apparatus comprises:

means for providing a first timing signal to the tuning element; and

means for providing a second timing signal to the tuning element. In some embodiments the apparatus comprises means for adjusting the level of the at least one timing signal.

In some embodiments the apparatus comprises:

means for generating a local oscillator signal for a transmitter; and

means for forming the at least one timing signal by using the local oscillator signal.

In some embodiments the apparatus comprises means for adjusting a pulse ratio of the at least one timing signal.

In some embodiments the apparatus comprises means for delaying the at least one timing signal. In some embodiments the apparatus comprises means for mixing a received radio frequency signal with the at least one timing signal.

In some embodiments the apparatus comprises means for tuning an impedance of a front end of the apparatus.