Self-oscillating mixer with Darlington transistors

Claim 2

A self-oscillating mixer for receiving an input signal and for generating an output signal containing the frequency products of the input signal and a local-oscillator signal, said self-oscillating mixer comprising: an input port for receiving the input signal; an output port for supplying the output signal; first and second bipolar transistors coupled as a Darlington pair, wherein the base of said first transistor is coupled to said input port, and wherein the common collectors of said transistors are coupled to said output port; and a feedback loop operable for coupling signals at the local-oscillator frequency from said common collectors to said base of said first transistor.

Claim 3

A self-oscillating mixer as recited in claim 1 wherein said feedback loop includes a resonator coupled between said base of said first transistor and said common collectors, and wherein the resonant frequency of said resonator determines the local-oscillator frequency of said mixer.

Claim 4

A self-oscillating mixer as recited in claim 1 wherein said feedback loop includes a dielectric resonator that couples signals at the local-oscillator frequency from a microstrip line connected between said common collectors and said output port to another microstrip line connected to said base of said first transistor.

Claim 5

A self-oscillating mixer as recited in claim 1 wherein said first and second bipolar transistors comprise NPN transistors.

Claim 6

A self-oscillating mixer as recited in claim 1 further comprising biasing means for biasing said transistors.

Claim 7

A self-oscillating mixer as recited in claim 5 wherein said transistors and said biasing means are fabricated as a monolithic integrated circuit.

Claim 8

A self-oscillating mixer as recited in claim 5 wherein said biasing means is operable for separately biasing said first and second transistors.

Claim 9

A self-oscillating mixer for receiving an input signal and for generating an output signal containing the frequency products of the input signal and a local-oscillator signal, said self-oscillating mixer comprising: an input port for receiving the input signal; an output port for supplying the output signal; first and second NPN transistors coupled as a Darlington pair, wherein the base of said first transistor is coupled to said input port, and wherein the common collectors of said transistors are coupled to said output port; means for biasing said transistors; and a feedback loop operable for coupling signals at the local-oscillator frequency from said common collectors to said base of said first transistor, wherein said feedback loop includes a dielectric resonator that couples signals at the local-oscillator frequency from a microstrip line connected between said common collectors and said output port to another microstrip line connected to said base of said first transistor, and wherein the resonant frequency of said dielectric resonator determines the local-oscillator frequency of said mixer.

Claim 10

A self-oscillating mixer for receiving an input signal and for generating an output signal containing the frequency products of the input signal and a local-oscillator signal, said self-oscillating mixer comprising: an input port for receiving the input signal; an output port for supplying the output signal; first and second NPN transistors coupled as a Darlington pair, wherein the base of said first transistor is coupled to said input port, and wherein the common collectors of said transistors are coupled to said output port; means for biasing said transistors; and a feedback loop operable for coupling signals at the local-oscillator frequency from said common collectors to said base of said first transistor, wherein said feedback loop includes a dielectric resonator that couples signals at the local-oscillator frequency from a microstrip line connected between said common collectors and said output port to another microstrip line connected to said base of said first transistor, and wherein the resonant frequency of said dielectric resonator determines the local-oscillator frequency of said mixer.

Claim 11

A frequency converter comprising: mixing means for receiving an input signal and a local-oscillator signal and for generating an output signal containing the frequency products of the local-oscillator and input signals, wherein said mixing means includes first and second bipolar transistors coupled as a Darlington pair, wherein the base of said first transistor is coupled to receive the input and local-oscillator signals, and wherein the common collectors of said transistors are coupled to generate the output signal; and local-oscillator means for supplying the local-oscillator signal to said mixing means.

Claim 12

A frequency converter comprising: mixing means for receiving an input signal and a local-oscillator signal and for generating an output signal containing the frequency products of the local-oscillator and input signals, wherein said mixing means includes first and second bipolar transistors coupled as a Darlington pair, wherein the base of said first transistor is coupled to receive the input and local-oscillator signals, and wherein the common collectors of said transistors are coupled to generate the output signal; and local-oscillator means for supplying the local-oscillator signal to said mixing means.

Claim 13

A frequency converter as recited in claim 9 wherein said local-oscillator means includes a feedback loop with a resonator coupled between said common collectors and said base of said first transistor, wherein said local-oscillator signal has a substantially constant frequency equal to the resonant frequency of said resonator.

Claim 14

A frequency converter as recited in claim 9 wherein said local-oscillator means includes a feedback loop that is operable for coupling signals at the local-oscillator frequency from said common collectors to said base of said first transistor.

Claim 15

A frequency converter as recited in claim 11 wherein said feedback loop includes a resonator coupled between said common collectors and said base of said first transistor, and wherein the resonant frequency of said resonator determines the local-oscillator frequency of said mixer.

Claim 16

A frequency converter as recited in claim 11 wherein said feedback loop includes a dielectric resonator that couples signals at the local-oscillator frequency from a microstrip line connected to said common collectors to another microstrip line connected to said base of said first transistor.

Claim 17

A frequency converter as recited in claim 9 wherein said first and second bipolar transistors comprise NPN transistors.

Claim 18

A frequency converter as recited in claim 9 wherein said mixing means further includes biasing means for biasing said transistors.

Claim 19

A frequency converter as recited in claim 15 wherein said transistors and said biasing means are fabricated as a monolithic integrated circuit.

Claim 20

A frequency converter as recited in claim 15 wherein said biasing means is operable for separately biasing said first and second transistors.

Claim 21

A frequency converter comprising: mixing means for receiving an input signal and a local-oscillator signal and for generating an output signal containing the frequency products of the local-oscillator and input signals, wherein said mixing means includes first and second NPN transistors coupled as a Darlington pair, wherein the base of said first transistor is coupled to receive the input and local-oscillator signals and the common collectors of said transistors are coupled to generate the output signal, and wherein said mixing means further includes means for separately biasing said first and second transistors; and a feedback loop operable for supplying the local-oscillator signal to said mixing means, wherein said feedback loop includes a dielectric resonator that couples signals at the local-oscillator frequency from a microstrip line connected to said common collectors to another microstrip line connected to said base of said first transistor, and wherein the resonant frequency of said dielectric resonator determines the local-oscillator frequency of said frequency converter.

Claim 22

A frequency converter comprising: mixing means for receiving an input signal and a local-oscillator signal and for generating an output signal containing the frequency products of the local-oscillator and input signals, wherein said mixing means includes first and second NPN transistors coupled as a Darlington pair, wherein the base of said first transistor is coupled to receive the input and local-oscillator signals and the common collectors of said transistors are coupled to generate the output signal, and wherein said mixing means further includes means for separately biasing said first and second transistors; and a feedback loop operable for supplying the local-oscillator signal to said mixing means, wherein said feedback loop includes a dielectric resonator that couples signals at the local-oscillator frequency from a microstrip line connected to said common collectors to another microstrip line connected to said base of said first transistor, and wherein the resonant frequency of said dielectric resonator determines the local-oscillator frequency of said frequency converter.