Filter-termination combination for multi-band receiver
View Patent ↗A termination/attenuation network applies to an input of a set-top box a MOCA channel signal having a narrow band of frequencies and included in RF signals having a wide band of frequencies received via a cable from a satellite antenna. The network includes a pair of series resistors and a parallel resistor coupled to a junction terminal between the pair of series resistors in a T-shaped configuration. A series-pass band-pass filter (L 1 , C 2 ) bypasses the pair of series resistors and a parallel band stop filter (L 2 , C 1 ) decouples the parallel resistor at the frequency band of the MOCA channel signal for selectively reducing attenuation at the frequency band of the MOCA channel signal.
1. A termination network coupled in operation to an input of a band-pass filter, comprising:
a first resistor coupled to a second resistor to form a voltage divider for voltage dividing a first radio frequency (RF) input signal that is applied, as attenuated by said voltage divider, to said filter input; and
a first resonant circuit responsive to said first RF input signal for controlling a magnitude of a second RF input signal developed at said filter input, said second RF input signal having a larger magnitude when said first RF input signal is at a resonant frequency of said first resonant circuit, relative to when said first RF input signal is outside a range of frequencies that includes said resonant frequency.
2. The termination network according to claim 1 , comprising a third resistor for coupling the voltage divided, first RF input signal to said filter input.
3. The termination network according to claim 1 wherein said filter comprises a band pass filter for passing a Multimedia over Cable Alliance (MOCA) frequency range.
4. The termination network according to claim 1 wherein said frequency range comprises a Multimedia over Cable Alliance (MOCA) frequency range and wherein an upper limit of the frequencies that are outside said range of frequencies is at least 2000 MHz.
5. The termination network according to claim 1 wherein said first resonant circuit comprises a parallel resonant circuit that is coupled in series with said second resistor.
6. The termination network according to claim 5 , comprising a third resistor for coupling to said filter input a signal developed in said series coupled parallel resonant circuit and said second resistor.
7. The termination network according to claim 6 wherein said first, second and third resistors are coupled in a T-shaped configuration.
8. The termination network according to claim 5 wherein said parallel resonant circuit comprises a first capacitor coupled in parallel with a first inductor.
9. The termination network according to claim 8 , comprising a second inductor coupled in series with said parallel resonant circuit.
10. The termination network according to claim 1 wherein said first resonant circuit comprises a series resonant circuit that is coupled to said filter input in a manner to bypass said first resistor.
11. The termination network according to claim 10 wherein said series resonant circuit comprises a second capacitor coupled in series with a third inductor.
12. The termination network according to claim 11 , comprising a third capacitor coupled in parallel with said third inductor.
13. The termination network according to claim 11 , comprising a parallel resonant circuit that is coupled in series with said second resistor.
14. The termination network according to claim 13 wherein said parallel resonant circuit comprises a first capacitor coupled in parallel with a first inductor.
15. The termination network according to claim 14 , comprising a second inductor coupled in series with said parallel resonant circuit.
16. The termination network according to claim 15 , comprising a third resistor having a first terminal coupled between said first and second resistors and a second terminal coupled to said filter input.
17. The termination network according to claim 16 wherein said first, second and third resistors form a T-shaped configuration.
18. A termination device comprising a band-pass filter, said termination device comprising:
a first resistor coupled to a second resistor to form a voltage divider for voltage dividing a first radio frequency (RF) input signal that is applied, as attenuated by said voltage divider, to an input of said band-pass filter; and
a first resonant circuit responsive to said first RF input signal for controlling a magnitude of a second RF input signal developed at said filter input, said second RF input signal having a larger magnitude when said first RF input signal is at a resonant frequency of said first resonant circuit, relative to when said first RF input signal is outside a range of frequencies that includes said resonant frequency.
19. The termination device of claim 18 wherein said first resonant circuit comprises a parallel resonant circuit that is coupled in series with said second resistor.