POWER INSERTER MODULE

Related Application

This Application is related to co-pending Provisional Application 60/708622, filed on August 16, 2005, for "Power Inserter Module," the teachings of which are incorporated herein by reference to the extent that they do not conflict herewith.

Field Of The Invention

The present invention is related generally to cable television devices, and more specifically to power inserter devices.

Summary Of The Invention

The present invention provides a power inserter module including means for directly connecting the module without use of cabling to a DC power supply, means for coupling the power to an RF amplifier, and means for coupling RF signals from the amplifier, while blocking DC power to an output port connected, for example, to a subscriber's television set, or converter, or modem.

Brief Description OfThe Drawings

Figure 1 shows a circuit schematic diagram for one embodiment of the invention;

Figure 2 shows the mechanical layout and interconnection of circuit components and a ground shield within a module housing for an embodiment of the invention;

Figure 3 shows a block schematic diagram of a typical cable antenna television system installation including the power inserter module of the present invention;

Figure 4 shows a top pictorial view of a housing and associated ports for one embodiment of the invention;

Figure 5 shows a closeup pictorial view of an unique FIC port for one embodiment of the invention;

Figure 6 shows a standard home installation pictorial view not having the benefit of the present invention;

Figure 7 is a pictorial view of a home installation including the present invention;

Figure 8 is a curve showing the insertion loss between the two RF ports for a power inserter module for one embodiment of the invention;

Figure 9 is a curve showing the return loss characteristics for an Amplifier DC/RF port for the power inserter of Figure 4;

Figure 10 is a curve showing isolation characteristics for transmission loss versus frequency between the two RF ports for the power inserter module of Figure 4; and

Figure 11 is a curve of the return loss at the RF output port for the power inserter module relative to Figure 4.

Detailed Description Of The Invention

With reference to Figure 1, the present power inserter module 2 in one embodiment of the invention includes an inductor Ll connected from a male pin 7 of a DC power port 6, to a female socket 1 of an RF and DC power port 4, for coupling DC power from a DC power supply (not shown) connected to port 6 to an amplifier connected to port 4. A capacitor C2 is connected between the end of the inductor Ll connected to a male pin 7 of port 6 and ground, whereby the inductor Ll provides a relatively high impedance to RF signals from the amplifier substantially preventing the signals from reaching the DC power port 6, and the capacitor C2 shunts to ground RF signals that may travel through inductor Ll. As a result, the combination of the high impedance of conductor Ll to RF signals, and the low impedance to RF signals provided by capacitor C2, effectively prevent RF signals from passing to the DC power port 6 and therefrom to a DC power supply connected thereto. A capacitor Cl is connected between the other end of conductor Ll and a female socket 9 of a subscriber RF

port 8 for both passing RF signals from the amplifier provided via port 4, while effectively blocking DC voltage from the subscriber port 8, thereby protecting a subscriber's TV, or modem, or other device that may be connected to port 8 for receiving the RF signals.

With reference to Figures 4, the housing 5 and ports 4, 6, and 8, respectively, for a power inserter module 2 for one embodiment of the invention are shown. An FIC connector is used to provide the port 6, and permits the power inserter module 2 to be directly connected to a power supply 20 (see Figure 7) without use of any connecting cables. Port 4, for connection to an amplifier for supplying DC voltage thereto, and for receiving RF signals from the amplifier, is provided by an F-type female port, for example. Port 8 for providing RF signals to each subscriber's television or modem, for example, is also provided by an F- type female port, in this example. Note that the use of F-τype female ports is not meant to be limiting, and they can in certain applications be male ports, for example.

Figure 5 is a close-up view of a power port 6 utilizing a male FIC connector.

Figure 6 is a pictorial view of a standard home installation requiring a cable 19 to be connected from a DC power supply 20 to a power inserter 22 having a cable connection 24 to an amplifier for providing power thereto, and another cable 26 for supplying RF signals to a subscriber's television set or modem.

Figure 7 is a pictorial view showing the improvement in both the appearance and reliability provided by the power inserter module 2 of the present invention, whereby its male

FIC port 6 is directly connected to an F-type female port 40 of the DC power supply 20. The DC/RF port 4 has an F-type female port directly connected to a male connector 28 of cable 24 for providing power to an amplifier (not shown) connected at the other end of cable 24, and receives RF signals from the amplifier, as previously mentioned. Also, port 8 has an F- type female port connected to a male F-type connector 29 at one end of cable 26, for providing RF signals to a subscriber. Cable 19 of Figure 16 is eliminated.

In one embodiment of the invention, the inductor Ll is 10 millihenrys (mh), capacitor Cl is 2200 picofarads (pf), and capacitor C2 is 5600 picofarads (pf). With reference to Figure 2, the capacitors Cl and C2 are physically mounted within the housing 5 for power inserter module 2 as shown, and interconnected as shown to inductor Ll, otherwise electrically interconnections are as previously described. A ground shield 3 is used in the central interior portion of the housing 5 for providing RF radiation shielding for Power Supply port 6 to further protect a DC power supply connected thereto from RF associated with ports 4 and 8. Note that the shield 3 typically consists of ferromagnetic material. The values of capacitor Cl, C2, and inductor Ll, as indicated herein from tests made in an engineering prototype are not meant to be limiting, and can in certain applications be other than the values provided herein.

Figure 3 shows the present power inserter module 2 connected into a typical installation, that includes a cable antenna television subscriber amplifier 10 having an input port 12 for receiving RF signals from a cable television system, a power port 14, and a combined power port and RF port 16. Port 16 connected by a connector 13 and a jumper cable 18 to port 4 (via connector 11) of the present power inserter module 2, for both

receiving DC power from the latter, and for supplying RF signals to the latter. In turn power inserter module 2 feeds RF signals via capacitor Cl to its port 8 for delivery to a subscriber, as previously mentioned. Also, as previously mentioned, the DC power FIC port 6 of power inserter module 2 is connected directly to a DC power supply 20 via the latter' s port 40. With the values previously given for the capacitor Cl, capacitor C2, and inductor Ll, and when used in a system as shown in Figure 3, the present power inserter module 2 provides an insertion loss of less than 0.3dB from 5 MHz to 1000 MHz, a return loss greater than 25dB, and an RF isolation to power supply 20 of greater than 6OdB. In this regard, Figures 8 through 11 show curves of insertion loss between ports 4 and 8, return loss DC/RF at port 4, RF isolation between ports 4 and 8, and return loss RF at port 8, respectively. Note that amplifier 10 includes an RF amplifier 34, RF signal diverters 30 and 36, and DC blocking capacitors 32 and 38, are connected as shown. Also note that in Figure 3, power inserter module 2 shows an alternative arrangement for the ports, whereby ports 4 and 6 are located on opposing ends of power inserter module 2, and port 8 is located on one side of power inserter module 2.

Although various embodiments of the present invention have been shown and described, they are not meant to be limiting. Those of skill in the art may recognize certain modifications to these embodiments, which modifications are meant to be covered by the spirit and scope of the appended claims.