Radio frequency signal frequency converter

• US 5,323,064 A
• Filed: 04/26/1993
• Issued: 06/21/1994
• Est. Priority Date: 04/26/1993
• Status: Expired due to Term

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Tajima, Yusuke, Kaczman, Daniel L., Cole, J. Bradford, Olsen, Erick A., Bacon, Peter
• Primary Examiner(s): Callahan, Timothy P.
• Assistant Examiner(s): LAM, TUAN THIEU
• Application Number:
  US08/053,126
• Time in Patent Office: 421 Days
• Field of Search: 307/242, 307/246, 307/571, 307/271, 307/529, 307/592, 307/39, 307/243, 328/104, 328/154, 328/15, 455/333
• US Class Current: 327/114
• CPC Class Codes: H04B 1/16 Circuits
• CPC Class Codes: H04B 1/26 for superheterodyne receivers multiple frequency-changing H03D7/16

Abstract

A switchable, dual channel frequency converter is provided. The converter includes a semiconductor body having formed as a monolithic microwave integrated circuit: a pair of input signal channels; a pair of output signal channels; and, a mixer and multiplexer means, disposed between the pair of input signal channels and the pair of output signal channels, for converting the frequency of signals fed to the pair of input signal channels to a different frequency and for directing the frequency converted signals to the pair of output signal channels selectively in accordance with a control signal. The mixer and multiplexer means includes: a pair of mixers coupled to the pair of input signal channels and a common local oscillator signal; and a multiplexer network. The mixers covert the radio frequency of the signals in the pair of input signal channels into a corresponding pair of intermediate frequency signal channels. The multiplexer network includes a pair of input ports fed by the pair of intermediate frequency signal channels and a pair of output ports which feed the pair of output signal channels. A control signal is fed to the multiplexer network. The power transfer of the intermediate frequency signals through the multiplexer network to the output signal channels is substantially the same (i.e., less than 0.5 db difference) independent of the state of the control signal.

Claims

1. A switchable, dual channel frequency converter, comprising:

a semiconductor body having formed as a monolithic microwave integrated circuit;

a pair of input signal channels;

a pair of output signal channels; and

, a mixer and multiplexer means, disposed between the pair of input signal channels and the pair of output signal channels, for converting the frequency of signals fed to the pair of input signal channels to a different frequency and for directing the frequency converted signals to the pair of output signal channels selectively in accordance with a control signal;

wherein the mixer and multiplexer means includes;

a pair of mixers, each one being coupled to a corresponding one of the pair of input signal channels and a common local oscillator signal; and

,

a pair of multiplexers, each one being coupled to an output of a corresponding one of the mixers; and

wherein each one of the pair of multiplexers is responsive to a control signal and includes a pair of inputs and an output, the pair of inputs of each one of the multiplexers being coupled to the outputs of the pair of mixers, the outputs of the pair of multiplexers being coupled to the pair of output signal channels and, wherein;

when the control signal is in a first state, a first one of the pair of input channels is coupled to a first one of the pair of output channels through a first one of the pair of mixers and a first one of the pair of multiplexers, while a second one of the pair of input channels is coupled to a second one of the pair of output channels through a second one of the pair of mixers and a second one of the pair of multiplexers;

when the control signal is in a second state the first one of input channels is coupled to the second one of the pair of output channels through the first one of the pair of mixers and the second one of the pair of multiplexers, while the second one of the pair of input channels is coupled to a first one of the pair of output channels through a second one of the pair of mixers and a first one of the pair of multiplexers;

when the control signal is in a third state, the first one of the pair of input channels is coupled to the first one of the pair of output channels through the first one of the pair of mixers and the first one of the pair of multiplexers and is also coupled to the second one of the pair of output channels through the first one of the pair of mixers and the second one of the pair of multiplexers, while the second one of the pair of input channels is decoupled from both the first and second output channels; and

,

when the control signal is in a fourth state, the first one of the pair of input channels is decoupled from both the first and second output channels, while the second one of the pair of input channels is coupled to the first one of the pair of output channels through the second one of the pair of mixers and the first one of the pair of multiplexers and is also coupled to the second one of the pair of signal channels through the second one of the pair of mixers and the second one of the multiplexers.

2. The converter recited in claim 1 wherein each one of the multiplexers includes a pair of transistor switching networks, such pair of switching networks having input terminals fed by the pair of input channels and a pair of output terminals connected to a common one of the pair of output channels, and wherein in each one of the four states of the control signal, when one of the pair of switching networks decouples the input terminal from ground terminal and couples it to the common output channel, the other one of the pair of switching networks decouples the input terminal from common channel couples it to ground.

3. The converter recited in claim 2 wherein the power transfer of the switching network is substantially the same independent of the state of the control signal.

4. The converter recited in claim 3 wherein each one of the transistor switching networks includes a pair of field effect transistors, one of the transistors having its source and drain electrodes coupled serially between the input terminal and the output terminal and the other one of the transistors having its source and drain electrodes serially coupled between the input terminal and the ground terminal, and wherein the gate electrodes are coupled to the control signal and, for each one of the four states of the control signal, drives one of the pair of transistors towards a conducting state and the other towards a non-conducting state.

5. The converter recited in claim 4 including a third field effect transistor, and wherein one of the source and drain electrodes of each of the pair of transistors are connected at a junction, the source and drain electrodes of the third transistor being serially connected between the junction and the output terminal.

6. The converter recited in claim 5 including a capacitor connected in shunt with the source and drain electrodes of the first mentioned transistor.

7. The converter recited in claim 5 wherein the gate electrode of the third transistor is coupled to the control signal and, in response thereto, is driven to the same conducting/non-conducting state of the first mentioned one of the pair of transistors.

8. A multiplexer system, comprising:

(a) a pair of multiplexers, each one thereof comprising;

a pair of input terminals;

an output terminal; and

, means, responsive to a control signal, for coupling a first one of the pair of input terminals to the output terminal when the control signal is in a first state and for coupling a second one of the pair of input terminals to the output terminal when the control signal is in a second state; and

,

(b) wherein in each one of the two states of the control signal, when one of the pair of switching networks decouples the input terminal from ground terminal and couples it to the common output channel, the other one of the pair of switching networks decouples the input terminal from common channel couples it to ground; and

(c) wherein the power transfer of the pair of switching network is substantially equal independent of the state of the control signal; and

(d) wherein each one of the transistor switching networks includes a pair of field effect transistors, a first one of the pair of transistors having its source and drain electrodes coupled serially between the input terminal and the output terminal and the other one of the pair of transistors having its source and drain electrodes serially coupled between the input terminal and the ground terminal, and wherein the gate electrodes are coupled to the control signal and, for each one of the four states of the control signal, drives one of the pair of transistors towards a conducting state and the other towards a non-conducting state; and

(e) including a third field effect transistor, and wherein one of the source and drain electrodes of each of the pair of transistors are connected at a junction, the source and drain electrodes of the third transistor being serially connected between the junction and the output of the multiplexer system.

9. The multiplexer recited in claim 8 including a capacitor connected in shunt between the source and drain electrodes of the first one of the pair of transistors.

10. The multiplexer system recited in claim 8 wherein the gate electrode of the third transistor is coupled to the control signal and, in response thereto, is driven to the same conducting/non-conducting state of the first one of the pair of transistors.

11. A monolithic microwave integrated circuit, comprising:

a pair of input signal channels;

a pair of output signal channels; and

, a mixer and multiplexer means, disposed between the pair of input signal channels and the pair of output signal channels, for converting the frequency of signals fed to the pair of input signal channels to a different frequency and for directing the frequency converted signals to the pair of output signal channels selectively in accordance with a control signal, the mixer and multiplexer means includes;

a pair of mixers coupled to the pair of input signal channels and a common local oscillator signal; and

a multiplexer network, the mixers converting the radio frequency of the signals in the pair of input signal channels into a corresponding pair of intermediate frequency signal channels, the multiplexer network includes;

a pair of input ports fed by the pair of intermediate frequency signal channels and a pair of output ports which feed the pair of output signal channels;

a control signal being fed to the multiplexer network, when the control signal is in a first state, a first one of the pair of intermediate frequency signal channels is coupled to a first one of the pair of output channels, while a second one of the pair of intermediate frequency signal channels is coupled to a second one of the pair of output channels, when the control signal is in a second state, the first one of the pair of intermediate frequency signal channels is coupled to the second output channel, while the second intermediate frequency signal channel is coupled to the first output channel, when the control signal is in third state, the first intermediate frequency signal channel is coupled to the first output channel and is also coupled to the second output channel, while the second input channel is decoupled from both the first and second output channels, and when the control signal is in a fourth state, the first intermediate frequency signal channel is decoupled from both the first and second output channels, while the second intermediate frequency signal channel is coupled to the first output channel and is also coupled to the second output signal channel.

12. The integrated circuit recited in claim 11 wherein the power transfer of the intermediate frequency signals through the multiplexer network to the output signal channels is substantially the same in all four states of the control signal.

13. The integrated circuit recited in claim 12 wherein the power transfer of the intermediate frequency signals through the multiplexer network to the output signal channels differ by less than 0.5 db in all four states of the control signal.