RF amplifier with reduced power consumption

Claim 2

An amplifier for amplifying AC signals in an operating frequency range, comprising: a first transistor having first, second and third terminals, the first terminal being coupled to an input signal source; a second transistor having first, second and third terminals, the first terminal being coupled to the first terminal of the first transistor for signals in the operating frequency range, the second terminal of the second transistor being coupled to the second terminal of the first transistor for signals in the operating frequency range; a first bias voltage generator circuit coupled to the first terminal of the first transistor, the first bias voltage generator circuit being operable to provide a first bias voltage to the first terminal of the first transistor; a second bias voltage generator circuit coupled to the first terminal of the second transistor, the second bias voltage generator circuit being operable to provide a second bias voltage to the first terminal of the second transistor; and an impedance connected between the third terminal of the second transistor and the second terminal of the first transistor, the impedance being operable to conduct a bias current; wherein the first and second transistors are each operable to conduct a varying current in response to an input signal from the input signal source.

Claim 3

The amplifier of claim 1, further comprising a load impedance coupled to the second terminal of the second transistor, the load impedance being operable to conduct a variable current generated by the first and second transistors, and operable to convert the variable current into an output voltage.

Claim 4

The amplifier of claim 1, further comprising a resonant circuit connected between the first terminal of the first transistor and the first terminal of the second transistor, the resonant circuit being tuned to present a low impedance to signals in the operating frequency range and a high impedance to direct current.

Claim 5

The amplifier of claim 3, further comprising a second resonant circuit connected between the second terminal of the first transistor and the second terminal of the second transistor, the second resonant circuit being tuned to present a low impedance to signals in the operating frequency range and a high impedance to direct current.

Claim 6

The amplifier of claim 1, further comprising a resonant circuit connected between the second terminal of the first transistor and the second terminal of the second transistor, the resonant circuit being tuned to present a low impedance to signals in the operating frequency range and a high impedance to direct current.

Claim 7

The amplifier of claim 1, further comprising a capacitor connected between the first terminal of the first transistor and the first terminal of the second transistor.

Claim 8

The amplifier of claim 6, further comprising a second capacitor connected between the second terminal of the first transistor and the second terminal of the second transistor.

Claim 9

The amplifier of claim 1, further comprising a capacitor connected between the second terminal of the first transistor and the second terminal of the second transistor.

Claim 10

The amplifier of claim 1, wherein the impedance comprises an inductor.

Claim 11

The amplifier of claim 1, wherein the impedance comprises a resonant circuit tuned to present a high impedance to signals in the operating frequency range.

Claim 12

The amplifier of claim 1, further comprising: a voltage source; and a second impedance connected between the third terminal of the second transistor and the voltage source, the second impedance being operable to conduct the bias current.

Claim 13

The amplifier of claim 11, wherein the second impedance comprises an inductor.

Claim 14

A cellular telephone comprising: a microphone; a speaker; an antenna operable to transmit and receive broadcast electromagnetic signals; internal circuitry coupled to the microphone and operable to receive voice signals from the microphone, the internal circuitry being coupled to the speaker and operable to transmit voice signals to the speaker, the internal circuitry being coupled to the antenna and operable to transmit and receive RF signals to and from the antenna, the internal circuitry including an RF amplifier operable to amplify at least one of the RF signals, the RF amplifier having: a first transistor having a gate terminal coupled to an input signal source; a second transistor having a gate terminal coupled to the gate terminal of the first transistor for signals in the operating frequency range, the second transistor further having a drain terminal coupled to a drain terminal of the first transistor for signals in the operating frequency range; a first bias voltage generator circuit coupled to the gate terminal of the first transistor, the first bias voltage generator circuit being operable to provide a first bias voltage to the gate terminal of the first transistor; a second bias voltage generator circuit coupled to the gate terminal of the second transistor, the second bias voltage generator circuit being operable to provide a second bias voltage to the gate terminal of the second transistor; an impedance connected between a source terminal of the second transistor and the drain terminal of the first transistor, the impedance being operable to conduct a bias current; wherein the first and second transistors are each operable to conduct a varying current in response to an input signal from the input signal source.

Claim 15

A cellular telephone comprising: a microphone; a speaker; an antenna operable to transmit and receive broadcast electromagnetic signals; internal circuitry coupled to the microphone and operable to receive voice signals from the microphone, the internal circuitry being coupled to the speaker and operable to transmit voice signals to the speaker, the internal circuitry being coupled to the antenna and operable to transmit and receive RF signals to and from the antenna, the internal circuitry including an RF amplifier operable to amplify at least one of the RF signals, the RF amplifier having: a first transistor having a gate terminal coupled to an input signal source; a second transistor having a gate terminal coupled to the gate terminal of the first transistor for signals in the operating frequency range, the second transistor further having a drain terminal coupled to a drain terminal of the first transistor for signals in the operating frequency range; a first bias voltage generator circuit coupled to the gate terminal of the first transistor, the first bias voltage generator circuit being operable to provide a first bias voltage to the gate terminal of the first transistor; a second bias voltage generator circuit coupled to the gate terminal of the second transistor, the second bias voltage generator circuit being operable to provide a second bias voltage to the gate terminal of the second transistor; an impedance connected between a source terminal of the second transistor and the drain terminal of the first transistor, the impedance being operable to conduct a bias current; wherein the first and second transistors are each operable to conduct a varying current in response to an input signal from the input signal source.

Claim 16

The cellular telephone of claim 13, wherein the amplifier further comprises a load impedance coupled to the drain terminal of the second transistor, the load impedance being operable to conduct a variable current generated by the first and second transistors, and operable to convert the variable current into an output voltage.

Claim 17

The cellular telephone of claim 13, wherein the amplifier further comprises a resonant circuit connected between the gate terminal of the first transistor and the gate terminal of the second transistor, the resonant circuit being tuned to present a low impedance to signals in the operating frequency range and a high impedance to direct current.

Claim 18

The cellular telephone of claim 13, wherein the amplifier further comprises a resonant circuit connected between the drain terminal of the first transistor and the drain terminal of the second transistor, the resonant circuit being tuned to present a low impedance to signals in the operating frequency range and a high impedance to direct current.

Claim 19

The cellular telephone of claim 13, wherein the amplifier further comprises a capacitor connected between the first terminal of the first transistor and the first terminal of the second transistor.

Claim 20

The cellular telephone of claim 17, wherein the amplifier further comprises a second capacitor connected between the second terminal of the first transistor and the second terminal of the second transistor.

Claim 21

The cellular telephone of claim 13, wherein the amplifier further comprises a capacitor connected between the second terminal of the first transistor and the second terminal of the second transistor.

Claim 22

The cellular telephone of claim 13, wherein the impedance comprises an inductor.

Claim 23

The cellula r telephone of claim 13, wherein the impedance comprises a resonant circuit tuned to present a high impedance to signals in the operating frequency range.

Claim 24

The cellular telephone of claim 13, wherein the amplifier further comprises: a voltage source; and a second impedance connected between the third terminal of the second transistor and the voltage source, the second impedance being operable to conduct the bias current.

Claim 27

The method of claim 23, further comprising conducting the output current by a load impedance to generate an output voltage at the output node.