An RF Assembly for RF power combining The present invention relates to an RF assembly for RF power combining .

RF power combiners are devices used in radio technology when there is a requirement of combining RF (radio frequency) power or RF signals. RF power combiners receive a plurality of RF inputs and transform the impedance of the received RF inputs to impedance of a single transmission line as output.

In RF applications, whenever a requirement of RF power combining appears, simultaneously there is a requirement to control the propagating RF power at its common (single) output. Therefore, it is needed to measure the Reflected wave i.e. the RF power entering the power combiner and to measure the Forward wave i.e. the RF power exiting the power

combiner. In radio technology, Directional couplers are devices that allow these measurements and are commonly used in RF systems .

In general, directional couplers are 4 -port RF devices in which there is a primary transmission line (e.g. from a first port to a second port of the directional coupler) and a secondary transmission line (e.g. from a third port to a fourth port of the directional coupler) . In the directional coupler, the secondary transmission line is set close enough to the primary transmission line, such that these lines are coupled. Some part of energy passing through the primary transmission line gets coupled to the secondary transmission line and depending on direction of propagation of RF power in the primary transmission line, i.e. between the first and the second port of the directional coupler, an RF signal appears in either the third port or the fourth port of the secondary transmission line. This appearance of RF signal at the third port or the fourth port of the secondary transmission line provides an opportunity to measure the RF power passing in both directions through the primary transmission line without disturbing the transmission of RF power through the primary transmission line.

In general, directional couplers are holistic and independent devices and are connected downstream or upstream to the other devices, such as, in this case, the power combiner, in the RF system or RF tract. As a result of being holistic and

independent device, when the directional coupler is attached into a RF tract with the power combiner, the result is a big total footprint and higher costs. Moreover, physical

contacts, for example waveguide flanges, established between the directional coupler and the power combiner in the RF tract needs to be protected against disruption in order to ensure proper functioning of the directional coupler.

Moreover, assembling such a RF tract or RF system with multiple RF devices i.e. the directional coupler and the power combiner is complex and requires expertise and

experience.

Thus the object of the present technique is to provide an RF assembly which is compact, easy to integrate into a RF tract, and which at least partially obviates possibilities of disruption of connection between the directional coupler and the power combiner in the RF tract.

The above objects are achieved by an RF assembly for RF power combining according to claim 1 of the present technique.

Advantageous embodiments of the present technique are

provided in dependent claims. Features of claim 1 may be combined with features of dependent claims, and features of dependent claims can be combined together. According to an aspect of the present technique, an RF assembly for RF power combining is presented. The RF assembly includes a power combining unit, a directional coupler and a common casing. The power combining unit and the directional coupler are arranged inside the common casing. As a result, the RF assembly is compact and easy to integrate into a RF tract. Moreover, the casing ensures that any possibility of disruption of connection between the directional coupler and the power combiner, when integrated in a RF tract, is at least partially obviated.

In an embodiment of the RF assembly, the power combining unit and the directional coupler are arranged in the common casing such that the power combining unit and the directional coupler are at fixed positions relative to each other and to the common casing. This ensures that when being integrated into a RF tract or being stored or transported or while in operation as part of a RF tract, the directional coupler and the power combiner are protected against physical

disturbances ensuring the connections inside the RF assembly are intact and optimally functional.

In another embodiment of the RF assembly, the common casing encases the power combining unit and the directional coupler electrically connected to each other by a single output transmission line within the common casing. Thus the common casing protects the single output transmission line and further ensures that any possibility of disruption of connection between the directional coupler and the power combiner, when integrated in a RF tract, is at least

partially obviated.

In another embodiment of the RF assembly, the common casing includes RF inputs on a first side of the common casing. The RF inputs are connected to the power combining unit. This ensures that RF power can be conveniently provided to the power combining unit arranged inside the common casing through the RF inputs and without requiring disassembly of or opening of the common casing. The RF inputs may be connected to the power combining unit in parallel.

In another embodiment of the RF assembly, the common casing includes at least one, particularly exactly one RF output. The RF output is connected to the directional coupler. This ensures that RF power can be conveniently obtained from the directional coupler arranged inside the common casing through the RF output and without requiring disassembly of or opening of the common casing. To be more specific, the RF output is connected to a primary transmission line of the directional coupler .

In another embodiment of the RF assembly, the at least one, particularly exactly one RF output is on a second side of the common casing. The second side is opposite to the first side of the common casing. This ensures that RF assembly may be fabricated in a further compact form, because the first side of the common casing does not need to be large enough to accommodate the RF output as well as the RF inputs. Moreover, this also provides ease of physical integration into a RF tract as the RF inputs and the RF output arranged opposite to each other provide a convenient orientation.

In another embodiment of the RF assembly, the common casing further includes at least one directional coupler output port. In a related embodiment the RF assembly includes two directional coupler output ports. Each of the directional coupler output ports is connected to the directional coupler. This ensures that RF signal appearing from the directional coupler can be conveniently obtained or accessed for

measurement through the directional coupler output ports and without requiring disassembly of or opening of the common casing. To be more specific, in embodiments where the RF assembly includes two directional coupler output ports, the directional coupler output ports are connected to a secondary transmission line of the directional coupler; one directional coupler output port at one end of the secondary transmission line and the other directional coupler output port at another end of the secondary transmission line.

In another embodiment of the RF assembly, the directional coupler output port is on a second side of the common casing. The second side is opposite to the first side of the common casing. This ensures that RF assembly may be fabricated in a further compact form, because the first side of the common casing does not need to be large enough to accommodate the directional coupler output port as well as the RF inputs. In another embodiment of the RF assembly, the common casing is cuboidal in shape. Such a casing is easy to fabricate and can be fabricated in a size that is compatible with

standardized frames or enclosures for mounting multiple equipment modules.

In another embodiment of the RF assembly, the common casing is adapted to be mountable inside a 19 -inch rack. Such 19- inch racks or 19 -inch cabinets are used in various RF tracts or systems and thus the RF assembly is physically compatible to be integrated in such RF tracts or systems.

In another embodiment of the RF assembly, the common casing includes a mounting means for mounting the RF assembly inside a 19 -inch rack. Thus requirement of additional means for mounting or complicated contraptions for mounting the RF assembly inside a 19-inch rack is at least partially

obviated.

In another embodiment of the RF assembly, the mounting means is a sliding means. The RF assembly is mountable inside a 19- inch rack by slidingly engaging the sliding means with rails of the 19 -inch rack. This at least partially obviates

requirement of attaching and/or detaching the RF assembly and the 19-inch rack. Moreover, the RF assembly can be easily dismounted from the 19 -inch rack which may be required for inspection or maintenance of the RF assembly or the 19 -inch rack or any other components mounted on the 19 -inch rack.

In another embodiment of the RF assembly, the mounting means is a fastening means for fixedly mounting the RF assembly inside a 19-inch rack. Thus, when mounted inside the 19-inch rack the RF assembly stays in place and does not dislocate due to physical disturbances of the 19 -inch rack or the surroundings, this further helps in maintaining proper connections between the RF assembly and the other components of a RF tract.

In another embodiment of the RF assembly, the mounting means is located on other side of the common casing. The other side is distinct from the first side and the second side of the common casing. Thus when mounted in a 19 -inch rack the RF inputs, the RF output and the one or more directional coupler output ports are easily accessible from a front or back side of the 19 -inch rack.

In another embodiment of the RF assembly, the common casing is cylindrical in shape. Such a casing is easy to fabricate and can be fabricated in various sizes that are compatible with various RF tracts or with standardized frames or enclosures for mounting multiple equipment modules.

The present technique is further described hereinafter with reference to illustrated embodiments shown in the

accompanying drawing, in which:

FIG 1 illustrates an RF assembly 1 for RF power

combining, in accordance with aspects of the present technique.

Hereinafter, above-mentioned and other features of the present technique are described in details. Various

embodiments are described with reference to the drawing, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be noted that the illustrated embodiments are intended to explain, and not to limit the invention. It may be evident that such embodiments may be practiced without these specific details.

In FIG 1 an RF assembly 1 for RF power combining according to the present invention is shown. The RF assembly 1 includes a power combining unit 3, a directional coupler 4 and a common casing 2. The power combining unit 3 and the directional coupler 4 are arranged inside the common casing 2. The power combining unit 3 is a RF power combining circuit that accepts multiple input RF signals and deliver a single RF output signal. The power combining unit 3 is connected to RF inputs 7. The power combining unit 3 receives RF power from the plurality of RF inputs 7 via inner conductors 9 of the RF inputs 7 and transform the impedance of the received RF power from the RF inputs 7 to impedance of a resultant single output . The resultant single output exits the power combining unit 3 via a single output transmission line 5. The power combining unit 3 may be of various types, for example zero-degree RF power combiners, and may have any technical specification .

It may be noted that in the present disclosure the term connected or like phrases mean linked by a transmission means such that RF power can transmit via the transmission means. Thus when a first entity is said to be connected to a second entity, then the first entity is linked to the second entity via a transmission means, e.g. a RF conductor, such that RF power can transmit between the first and the second entity via the transmission means. To explain further, the power combining unit 3 is connected to the RF inputs 7 means the power combining unit 3 is linked to the RF inputs 7 via means of a transmission means, in this case the inner conductors 9, such that RF power or RF signal is capable of being transmitted between the power combining unit 3 and the

RF inputs 7. Thus, when a RF signal is received or applied at the RF inputs 7, the received or applied RF signal from each of the RF inputs 7 is transmitted to the power combining unit 3.

The directional coupler 4 includes at least a primary

transmission line 11 and a secondary transmission line 12. The primary transmission line 11 and the secondary

transmission line 12 are placed in such vicinity of each other that the primary transmission line 11 and the secondary transmission line 12 get coupled to each other.

In the RF assembly 1, the common casing 2 encases or encloses or houses the power combining unit 3 and the directional coupler 4. The power combining unit 3 and the directional coupler 4 are connected or electrically connected to each other by the single output transmission line 5 within the common casing 2. Thus, the RF signal, if any, exiting the power combining unit 3 is transmitted to the directional coupler 4. More precisely, the single output transmission line 5 connects the power combining unit 3 and the primary transmission line 11 of the directional coupler 4. Thus, the RF signal exiting the power combining unit 3 is transmitted through the directional coupler 4 via the primary

transmission line 11 of the directional coupler 4. The primary transmission line 11 of the directional coupler 4 is in turn connected to an RF output 6. The secondary

transmission line 12 is connected to at least one directional coupler output port 8, preferably to two directional coupler output ports 8. As is depicted in FIG 1, one end (not shown) of the secondary transmission line 12 of the directional coupler 4 is connected to one directional coupler output port 8 and the other end (not shown) of the secondary transmission line 12 of the directional coupler 4 is connected to the other directional coupler output port 8.

The common casing 2 (hereinafter referred to as casing 2) is a covering or an enclosure and may have varied shapes and sizes, for example the casing 2 may be, but not limited to, a box, i.e. having a cuboidal 3D shape, cylindrical, hexagonal prism, and so on and so forth. The casing 2 may be formed of any suitable material used to house RF signal processing devices or RF transmission lines, for example, the casing 2 may be formed of metals, alloys, polymers, plastics, and so on and so forth. The casing 2 includes the RF output 6, the RF inputs 7, and the directional coupler output port 8 i.e. the RF output 6, the RF inputs 7, and the directional coupler output port 8 are present on one or more of walls (not shown) of the casing 2.

In one embodiment of the RF assembly 1 the casing 2

completely covers or fully encloses a volume (not shown) in which the power combining unit 3 and the directional coupler 4 are situated. In this embodiment the volume is not covered or not enclosed by the casing 2 only at the RF output 6, the RF inputs 7, and one or more of the directional coupler output ports 8.

In an embodiment of the RF assembly 1, the power combining unit 3 and the directional coupler 4 are arranged in the casing 2 in such a way that the power combining unit 3 and the directional coupler 4 are at fixed positions relative to each other and to the casing 2. This is achieved by fixing or fastening, for example by using screws, the power combining unit 3 and the directional coupler 4 to the casing 2.

Alternatively, the RF assembly 1 may be fabricated in a way that the power combining unit 3 and the directional coupler 4 are fabricated on a wall (not shown) of the casing 2. One example of such fabrication is by printing a circuit of the power combining unit 3 and transmission lines 11,12 of the directional coupler 4 on the wall of the casing 2.

In one embodiment of the RF assembly 1, the casing 2 includes RF inputs 7 on a first side 21 of the casing 2. The RF inputs 7 are connected to the power combining unit 3 in parallel via the inner conductors 9 of the RF inputs 7. The RF output 6 is on a second side 22 of the casing 2. The second side 22 is opposite to the first side 21 of the casing 1. Thus, when the casing 2 is cuboidal in shape, the first side 21 and the second side 22 are opposite faces of the cuboid. Furthermore, when the casing 2 is cylindrincal in shape, or a hexagonal prism, then the first side 21 and the second side 22 are opposite faces of the cylinder or the hexagonal prism i.e. the circular sides in case of the cylinder or the hexagonal sides in case of the hexagonal prism. In another embodiment of the RF assembly 1, the one or more of the directional coupler output ports 8 are on the second side 22 of the casing 2, when the RF output 6 is also on the second side 22 but the RF inputs 7 are on the first side 21 of the casing 1.

In the embodiment of the RF assembly 1, where the casing 2 is cuboidal in shape, the casing 2 is adapted to be mountable inside a 19 -inch rack. Such 19 -inch racks or 19 -inch cabinets are well known and used prevalently as standardized frame or enclosure for mounting multiple equipment modules. The dimensions of the casing 2 are such that the casing 2, and thus the RF assembly 1, is compatible with the 19 -inch racks i.e. the casing 2 and thus the RF assembly 1 is mountable in a 19 -inch rack as one of the modules. The casing 2 may additionally include a mounting means 14 for mounting the RF assembly 1 inside a standard 19 -inch rack. In one embodiment of the RF assembly 1, the mounting means 14 is located on other side 23, 24 of the casing 2. The other side 23,24 is distinct from the first side 21 and the second side 22 of the casing 2.

In an embodiment of the RF assembly 1, the mounting means 14 is a sliding means. In this embodiment, the RF assembly 1 is mountable inside a 19 -inch rack by slidingly engaging the sliding means with rails of the 19 -inch rack. Generally, a pair of rails is mounted or fixed directly onto the 19-inch rack, and the RF assembly 1 then slides into the 19 -inch rack along the rails by contacting the rails of the 19 -inch rack with the sliding means of the casing 2. When in a desired position in the 19-inch rack, the casing 2 may then be locked in the desired position by an additional locking mechanism (not shown) to the 19 -inch rack. In another embodiment of the RF assembly 1, the mounting means 14 is a fastening means for fixedly mounting the casing 2, and thus the RF assembly 1, inside the 19 -inch rack. The fastening means may be a bolt and screw mechanism or a clicklock mechanism. While the present technique has been described in detail with reference to certain embodiments, it should be appreciated that the present technique is not limited to those precise embodiments. Rather, in view of the present disclosure which describes exemplary modes for practicing the invention, many modifications and variations would present themselves, to those skilled in the art without departing from the scope and spirit of this invention. The scope of the invention is, therefore, indicated by the following claims rather than by the foregoing description. All changes, modifications, and variations coming within the meaning and range of equivalency of the claims are to be considered within their scope.