Circuits, Systems and Methods for Frequency Translation and Signal Distribution

• US 20080132193A1
• Filed: 01/17/2008
• Published: 06/05/2008
• Est. Priority Date: 11/03/2006
• Status: Active Grant

• Current Assignee: Entropic Communications, LLC (SoftBank Group Corp.)
• Original Assignee: RF Magic, Inc. (Maxlinear Incorporated)
• Inventors: Doherty, Peter, Petrovic, Branislav, Zeng, Yong
• Granted Patent: US 8,023,912 B2
• Time in Patent Office: Days
• US Class Current: 455/323
• CPC Class Codes: H04B 1/16 Circuits
• CPC Class Codes: H04B 1/28 the receiver comprising at least one semiconductor device having three or more electrodes
• CPC Class Codes: H04H 40/90 specially adapted for satellite broadcast receiving

Abstract

Circuits systems and methods for frequency translation and signal distribution includes a downconverter circuit having first and second inputs coupled to receive respective first and second input signals, and an output for providing a downconverted output signal. The downconverter circuit includes a mixer circuit, a first switch, and a second switch. The mixer includes a first input coupled to a reference source, a second input, and an output coupled to the downconverter circuit output. The first switch includes a first port coupled to the downconverter circuit first input, and a second port switchably coupled to the mixer circuit second input. The second switch includes a first port coupled to the downconverter circuit second input, and a second port switchably coupled to the mixer circuit second input.

Claims

1. A downconverter circuit for a signal distribution and frequency translation system, the downconverter circuit having first and second inputs coupled to receive respective first and second input signals, and an output for providing a downconverted output signal, the downconverter circuit comprising;

a mixer circuit having a first input coupled to a reference frequency source, a second input, and an output coupled to the downconverter circuit output;

a first switch having a first port coupled to the downconverter circuit first input, and a second port switchably coupled to the mixer circuit second input; and

a second switch having a first port coupled to the downconverter circuit second input, and a second port switchably coupled to the mixer circuit second input.

2. The downconverter circuit of claim 1, wherein the first and second switches are complementarily-switched.

3. The downconverter circuit of claim 1, wherein the first input signal originates from a first satellite, and the second input signal originates from a second satellite.

4. The downconverter circuit of claim 1, wherein at least a portion of the frequency source, or the mixer circuit, or the first or second switches comprises a differential signal path.

5. The downconverter circuit of claim 1, further comprise at least one buffer amplifier coupled between the downconverter circuit first input and the first switch, at least one buffer amplifier coupled between the downconverter circuit second input and the second switch, and at least one buffer amplifier coupled between the mixer circuit output and the downconverter circuit output.

6. The downconverter circuit of claim 1, further comprising:

a third switch having a first port coupled to the mixer circuit output, and a second port switchably coupled to the downconverter circuit output; and

a fourth switch having a first port coupled to the downconverter circuit first input, and a second port switchably coupled to the downconverter circuit output.

7. The downconverter circuit of claim 6, further comprising a fifth switch having a first port coupled to the downconverter circuit second input, and a second port switchably coupled to the downconverter circuit output.

8. A frequency translation and signal distribution system, comprising:

a first signal matrix comprising at least one input port operable to receive a signal and a plurality of output ports, the first signal matrix operable to couple a signal received on said at least one input port to any of the plurality of said output ports;

a second signal matrix comprising at least one input port operable to receive a signal and a plurality of output ports, the second signal matrix operable to couple a signal received on said at least one input port to any of the plurality of said output ports; and

a plurality of downconverter circuits, each downconverter having a first input coupled to a respective one of the first matrix output ports, a second input coupled to a respective one of the second matrix output ports, and an output port for providing a downconverted output signal, the downconverter circuit comprising;

a mixer circuit having a first input coupled to a reference frequency source, a second input, and an output coupled to the downconverter circuit output;

a first switch having a first port coupled to the downconverter circuit first input, and a second port switchably coupled to the mixer circuit second input; and

a second switch having a first port coupled to the downconverter circuit second input, and a second port switchably coupled to the mixer circuit second input.

9. The system of claim 8, wherein the first and second signal matrices comprises respective first and second N-way resistive divider circuits, each of the first and second N-way resistive divider circuits having an input port operable to receive a signal and a plurality of output ports, each of the first and second resistive divider circuits including a plurality of N parallel-coupled impedance transformers coupled between each'"'"'s respective input port and output ports, each of the plurality of the impedance transformers comprising:

a first resistor Rs having a first node coupled to a common input junction, and a second node; and

a second resistor Rp having a first node coupled to the second node of the first resistor, and a second node coupled to a signal ground,

wherein the resistance value of each of the first resistors Rs is substantially the value defined by the equation;

Rs=√

{square root over (N·

(N−

1))}·

R_esired

and wherein the resistance value of each of the second resistors Rp is substantially the value defined by the equation;

Rp=√

{square root over (N/(N−

1))}·

R_esired

and where R_desired is the desired impedance looking into the input port of the respective first or second N-way resistive divider circuit, and N is the number of impedance transformers included within the respective first or second N-way resistive divider circuit.

10. The system of claim 9, wherein each of the first resistors Rs comprises a plurality of series-coupled resistors.

11. The system of claim 8, wherein the first signal matrix includes a plurality of inputs, the first signal matrix further comprising:

a plurality of signal matrices, each signal matrix comprising at least one input port operable to receive a signal and a plurality of output ports, each of the plurality of signal matrices operable to couple a signal received on said input port to any of the plurality of said output ports; and

a plurality of combiners, each combiner having a plurality of inputs and a combiner output, wherein each combiner input port is coupled to a respective one output port of one of the plurality of matrices, whereby the combiner input ports are coupled to respective output ports of different matrices, and wherein each combiner output port is coupled to a first input or second input of a respective one of the downconverter circuits.

12. The system of claim 11,

wherein the plurality of signal matrices comprises:

a first switch matrix having at least one input port coupled to receive a respective at least one signal, and at least N output ports, the first switch matrix operable to couple a signal received on the at least one input port to any of the at least N output ports; and

a second switch matrix having at least one input port coupled to receive a respective at least one signal, and at least N output ports, the second switch matrix operable to couple a signal received on the at least one input port to any of the at least N output ports; and

wherein the plurality of combiners comprises a respective at least N combiners, each of the plurality of N signal combiners including a first input coupled to a respective one of the N outputs of the first switch matrix, and a second input coupled to a respective one of the N outputs of the second switch matrix.

13. The system of claim 12, wherein the first signal matrix includes a plurality of input ports, whereby at least one of the plurality of input ports is configured to receive a signal operating within a first frequency band and a signal operating within a second frequency band.

14. The system of claim 13, further comprising circuitry for supplying said signals operating within said first and second frequency bands, said circuitry comprising:

a frequency converter having a plurality of inputs coupled to receive the signal operating within the first frequency band, and a plurality of outputs, the frequency converter operable to either;

(i) pass the signal operable within the first frequency band therethrough without frequency translation, or (ii) frequency translate said signal from a first part of the first frequency band to a second part of the first frequency band; and

a plurality of signal lines, each coupled to receive the signal operating within the second frequency band,

wherein a respective one of the frequency converter outputs is coupled to a respective one of the signal lines, whereby the signal operating within the first frequency band is combined with the signal operating within the second frequency band.

15. The system of claim 14, wherein the frequency converter further includes:

a first frequency converter mixer coupled to receive the signal operating at the first part of the first frequency band, the first frequency converter mixer operable to frequency translate said signal input thereto to the second part of the first frequency band;

a second frequency converter mixer coupled to receive the signal operating at the second part of the first frequency band, the second frequency converter mixer operable to frequency translate said signal input thereto to the first part of the first frequency band;

a first bypass signal line coupled to receive the signal operating at the first part of the first frequency band, the first bypass signal line coupled to bypass the first frequency converter mixer; and

a second bypass signal line coupled to receive the signal operating at the second part of the first frequency band, the second bypass signal line coupled to bypass the second frequency converter mixer.

16. The system of claim 13, wherein the second signal matrix includes a plurality of input ports, whereby at least one of the plurality of input ports is configured to receive a signal operating within a first frequency band and a signal operating within a second frequency band.

17. The system of claim 16, further comprising circuitry for supplying said signals operating within said first and second frequency bands, said circuitry comprising:

a frequency converter having a plurality of inputs coupled to receive the signal operating within the first frequency band, and a plurality of outputs, the frequency converter operable to either;

(i) pass the signal operable within the first frequency band therethrough without frequency translation, or (ii) frequency translate said signal from a first part of the first frequency band to a second part of the first frequency band; and

a plurality of signal lines, each coupled to receive the signal operating within the second frequency band,

wherein a respective one of the frequency converter outputs is coupled to a respective one of the signal lines, whereby the signal operating with the first frequency band is combined with the signal operating within the second frequency band.

18. The system of claim 17, wherein the frequency converter further includes:

a first frequency converter mixer coupled to receive the signal operating at the first part of the first frequency band, the first frequency converter mixer operable to frequency translate said signal input thereto to the second part of the first frequency band;

a second frequency converter mixer coupled to receive the signal operating at the second part of the first frequency band, the second frequency converter mixer operable to frequency translate said signal input thereto to the first part of the first frequency band;

a first bypass signal line coupled to receive the signal operating at the first part of the first frequency band, the first bypass signal line coupled to bypass the first frequency converter mixer; and

a second bypass signal line coupled to receive the signal operating at the second part of the first frequency band, the second bypass signal line coupled to bypass the second frequency converter mixer.

19. The system of claim 8, further comprising at least one signal combiner, comprising:

a first input coupled to a respective output port of a first of the plurality of downconverter circuits; and

a second input coupled to a respective output port of a second of the plurality of downconverter circuits,

wherein the signal combiner is further configured to receive a signal operating within a predefined frequency band, whereby a downconverted signal output from the first or second downconverter circuits is included within said predefined frequency band.

20. The system of claim 19, further comprising circuitry for supplying said signal operating within the predefined frequency band, said circuitry comprising:

a frequency converter having a plurality of inputs coupled to receive the signal operating within the predefined frequency band, and a plurality of outputs, the frequency converter operable to either;

(i) pass the signal operable within the predefined frequency band therethrough without frequency translation, or (ii) frequency translate said signal from a first part of the predefined frequency band to a second part of the predefined frequency band.

21. The system of claim 20, wherein the frequency converter further includes:

a first frequency converter mixer coupled to receive the signal operating at the first part of the predefined frequency band, the first frequency converter mixer operable to frequency translate said signal input thereto to the second part of the predefined frequency band;

a second frequency converter mixer coupled to receive the signal operating at the second part of the predefined frequency band, the second frequency converter mixer operable to frequency translate said signal input thereto to the first part of the predefined frequency band;

a first bypass signal line coupled to receive the signal operating at the first part of the predefined frequency band, the first bypass signal line coupled to bypass the first frequency converter mixer; and

a second bypass signal line coupled to receive the signal operating at the second part of the predefined frequency band, the second bypass signal line coupled to bypass the second frequency converter mixer.

22. The system of claim 21, further comprising a frequency converter signal matrix having a plurality of inputs and a plurality of outputs, each input coupled to a respective one of the first or second frequency converter mixer outputs, or first or second bypass signal lines, and a group of at least two outputs coupled to a respective combiner.

23. In a downconverter circuit having a mixer circuit, and first and second switches, a method for downconverting, to an output frequency, each of the at least first and second signals supplied to the downconverter circuit, the method comprising:

supplying said at least first and second signals to respective at least first and second switches of said downconverter circuit;

controlling the first switch to a closed state to switchable couple the first signal to the mixer circuit and controlling the second switch to an open state, whereby said mixer circuit downconverts the first signal to the downconverted output frequency; and

controlling the first switch to an open state, and the second switch to a closed state to switchable couple the second signal to the mixer circuit, whereby said mixer circuit downconverts the second signal to the downconverted output frequency.

24. The method of claim 23, wherein supplying a first signal to a first switch comprises:

frequency multiplexing a signal operating within a first frequency band with a signal operating within a second frequency band; and

providing, as the first signal, the frequency-multiplexed signal to the first switch.

25. The method of claim 23, wherein the downconverter circuit further includes third and fourth switches, the method further comprising:

controlling the first and third switches to a closed state to switchable couple the first signal to the mixer circuit and controlling the second and fourth switches to an open state, whereby said mixer circuit downconverts the first signal to the downconverted output frequency;

or

controlling the first and third switches to an open state, and the second and fourth switches to a closed state to switchable couple the second signal to the mixer circuit, whereby said mixer circuit downconverts the second signal to the downconverted output frequency;

or

controlling the first, second, and third switches to an open state, and the fourth switch to a closed state to switchably couple the first signal through the downconverter circuit without frequency translation to an output port of the downconverter circuit.