Negative-resistance-compensated microwave buffer

Claim 2

A monolithic microwave buffer amplifier for operating at frequencies above a predetermined 3 dB rolloff frequency, said buffer amplifier comprising cascaded first and second stages, each having an input impedance including a capacitively-reactive component, said capacitively-reactive components, during operation of the first and second stages, cooperating to produce a 180° phase shift such that said reactive components appear collectively at the input of the first stage as a negative input resistance, said buffer amplifier further including at its input a positive resistance having a magnitude which at least cancels said negative input resistance.

Claim 3

A monolithic microwave buffer amplifier as in claim 1 where the positive resistance is electrically connected in parallel with the input of the first stage.

Claim 4

A monolithic microwave buffer amplifier as in claim 1 where the positive resistance is electrically connected in series with the input of the first stage.

Claim 5

A monolithic microwave buffer amplifier as in claim 1 where the magnitude of the positive resistance is substantially greater than the magnitude of the negative input resistance.

Claim 6

A monolithic microwave buffer amplifier for operating at frequencies above a predetermined 3 dB rolloff frequency, said buffer amplifier comprising cascaded first and second stages, each having an input impedance including a capacitively-reactive component, said capacitively-reactive components, during operation of the first and second stages, cooperating to produce a 180° phase shift such that said reactive components appear collectively at the input of the first stage as a negative input resistance of value R - , said buffer amplifier further including, electrically connected in parallel with the input of the first stage, an input resistance of value R, where 1/R=1/R eff +1/R + , the total input resistance of the buffer amplifier being substantially equal to R IN , where 1/R IN =1/R eff +1/R + +1/R, where R + is approximately equal to and substantially cancels the negative input resistance of value R - , and where R eff comprises the effective input resistance of the buffer amplifier.

Claim 7

A monolithic microwave buffer amplifier for operating at frequencies above a predetermined 3 dB rolloff frequency, said buffer amplifier comprising cascaded first and second stages, each having an input impedance including a capacitively-reactive component, said capacitively-reactive components, during operation of the first and second stages, cooperating to produce a 180° phase shift such that said reactive components appear collectively at the input of the first stage as a negative input resistance of value R - , said buffer amplifier further including, electrically connected in parallel with the input of the first stage, an input resistance of value R, where 1/R=1/R eff +1/R + , the total input resistance of the buffer amplifier being substantially equal to R IN , where 1/R IN =1/R eff +1/R + +1/R, where R + is approximately equal to and substantially cancels the negative input resistance of value R - , and where R eff comprises the effective input resistance of the buffer amplifier.

Claim 8

A monolithic microwave buffer amplifier for operating at frequencies above a predetermined 3 dB rolloff frequency, said buffer amplifier comprising cascaded first and second stages, each having an input impedance including a capacitively-reactive component, said capacitively-reactive components, during operation of the first and second stages, cooperating to produce a 180° phase shift such that said reactive components appear collectively at the input of the first stage as a negative input resistance of value R - , said buffer amplifier further including, electrically connected in series with the input of the first stage, an input resistance of value R, where R=R eff +R + , the total input resistance of the buffer amplifier being substantially equal to R IN , where R IN =R eff +R + +R - , where R + is approximately equal to and substantially cancels the negative input resistance of value R - , and where R eff comprises the effective input resistance of the buffer amplifier.

Claim 9

A monolithic microwave buffer amplifier for operating at frequencies above a predetermined 3 dB rolloff frequency, said buffer amplifier comprising cascaded first and second stages, each having an input impedance including a capacitively-reactive component, said capacitively-reactive components, during operation of the first and second stages, cooperating to produce a 180° phase shift such that said reactive components appear collectively at the input of the first stage as a negative input resistance of value R - , said buffer amplifier further including, electrically connected in series with the input of the first stage, an input resistance of value R, where R=R eff +R + , the total input resistance of the buffer amplifier being substantially equal to R IN , where R IN =R eff +R + +R - , where R + is approximately equal to and substantially cancels the negative input resistance of value R - , and where R eff comprises the effective input resistance of the buffer amplifier.

Claim 10

A monolithic microwave buffer amplifier for operating at frequencies above a predetermined 3 dB rolloff frequency, said buffer amplifier comprising: a. a first stage having an input impedance including a resistive component and a capacitively-reactive component; b. a second stage having an input impedance including a capacitively-reactive component, the input of said second stage being coupled to an output of the first stage; said capacitively-reactive components, during operation of the first and second stages, cooperating to produce a 180° phase shift such that said capacitively-reactive components appear collectively at the input of the first stage as a negative input resistance of value R - ; c. a resistance of value R electrically connected in parallel with the input of the first stage, where 1/R=1/R eff +1/R + ; the total input resistance of the buffer amplifier being substantially equal to R IN , where 1R IN =1/R eff +1/R + +1/R - , here R + is approximately equal to and substantially cancels the negative input resistance of value R - , and where R eff comprises the effective input resistance of the buffer amplifier.

Claim 11

A monolithic microwave buffer amplifier for operating at frequencies above a predetermined 3 dB rolloff frequency, said buffer amplifier comprising: a. a first stage having an input impedance including a resistive component and a capacitively-reactive component; b. a second stage having an input impedance including a capacitively-reactive component, the input of said second stage being coupled to an output of the first stage; said capacitively-reactive components, during operation of the first and second stages, cooperating to produce a 180° phase shift such that said capacitively-reactive components appear collectively at the input of the first stage as a negative input resistance of value R - ; c. a resistance of value R electrically connected in parallel with the input of the first stage, where 1/R=1/R eff +1/R + ; the total input resistance of the buffer amplifier being substantially equal to R IN , where 1R IN =1/R eff +1/R + +1/R - , here R + is approximately equal to and substantially cancels the negative input resistance of value R - , and where R eff comprises the effective input resistance of the buffer amplifier.

Claim 12

A monolithic microwave buffer amplifier for operating at frequencies above a predetermined 3 dB rolloff frequency, said buffer amplifier comprising: a. a first stage having an input impedance including a resistive component and a capacitively-reactive component; b. a second stage having an input impedance including a capacitively-reactive component, the input of said second stage being coupled to an output of the first stage; said capacitively-reactive components, during operation of the first and second stages, cooperating to produce a 180° phase shift such that said capacitively-reactive components appear collectively at the input of the first stage as a negative input resistance of value R - ; c. a resistance of value R electrically connected in series with the input of the first stage, where R=R eff +R + ; the total input resistance of the buffer amplifier being substantially equal to R IN , where R IN =R eff +R + +R - , where R + is approximately equal to and substantially cancels the negative input resistance of value R - , and where R eff comprises the effective input resistance of the buffer amplifier.

Claim 13

A monolithic microwave buffer amplifier for operating at frequencies above a predetermined 3 dB rolloff frequency, said buffer amplifier comprising: a. a first stage having an input impedance including a resistive component and a capacitively-reactive component; b. a second stage having an input impedance including a capacitively-reactive component, the input of said second stage being coupled to an output of the first stage; said capacitively-reactive components, during operation of the first and second stages, cooperating to produce a 180° phase shift such that said capacitively-reactive components appear collectively at the input of the first stage as a negative input resistance of value R - ; c. a resistance of value R electrically connected in series with the input of the first stage, where R=R eff +R + ; the total input resistance of the buffer amplifier being substantially equal to R IN , where R IN =R eff +R + +R - , where R + is approximately equal to and substantially cancels the negative input resistance of value R - , and where R eff comprises the effective input resistance of the buffer amplifier.

Claim 14

A monolithic microwave buffer amplifier as in claim 1, 5, 6, 7, or 8 where the first stage comprises an amplifier and the second stage comprises an impedance.

Claim 15

A monolithic microwave buffer amplifier as in claim 1, 5, 6, 7, or 8 where the first stage comprises a transistor.

Claim 16

A monolithic microwave buffer amplifier as in claim 10 where the transistor comprises a FET.

Claim 17

A monolithic microwave buffer amplifier as in claim 10 where the transistor comprises a bipolar transistor.

Claim 18

A monolithic microwave buffer amplifier as in claim 1, 5, 6, 7, or 8 where the input impedance of the buffer amplifier is substantially equal to the input resistance of said buffer amplifier.

Claim 19

A monolithic microwave buffer amplifier as in claim 1, 5, 6, 7, or 8 where the first stage comprises an emitter follower circuit.

Claim 20

A monolithic microwave buffer amplifier as in claim 14 where the second stage comprises a common emitter circuit.

Claim 21

A monolithic microwave buffer amplifier as in claim 14 where the second stage comprises a capacitive element.

Claim 22

A monolithic microwave buffer amplifier as in claim 1, 5, 6, 7, or 8 where the second stage comprises a common emitter circuit.

Claim 23

A monolithic microwave buffer amplifier as in claim 1, 5, 6, 7, or 8 where the second stage comprises a capacitive element.

Claim 24

A monolithic microwave buffer amplifier as in claim 1, 5, 6, 7 or 8 where the first and second stages each include a transistor.