US 6,121,838 A · Precision GaAs low-voltage DC amplifier

Abstract

A precision GaAs low-voltage DC amplifier includes a level shift circuit, an amplifier and a first and a second bias control circuit. The level shift circuit shifts an input signal to generate a level shifted input signal, whose bias level is controlled by a first bias control voltage. The amplifier amplifies the level shifted input signal to generate an output signal. The bias level of the output signal is controlled by a second bias control voltage. The first bias control circuit insures that the first bias control voltage varies as necessary with temperature to hold constant the bias level of the level shifted input signal. The second bias control circuit insures that the second bias control voltage varies as necessary with temperature to hold constant the bias level of the output signal.

Claims20

Dependent claims

A precision GaAs amplifier, comprising:

a) a first level shift circuit for level shifting an input signal to generate a level shifted input signal, the level shifted input signal having a first bias level controlled by a first bias control voltage;
b) an amplifier for amplifying the level shifted input signal to generate an output signal, the output signal having a second bias level controlled by a second bias control voltage;
c) a first bias control circuit for generating the first bias control voltage such that the first bias control voltage varies as necessary, with respect to a process that fabricated the GaAs amplifier, to hold constant the first bias level;
and
d) a second bias control voltage for generating the second bias control voltage.

2 more elements

A precision low-voltage GaAs amplifier comprising:

a multiplicity of DC coupled amplifier stages, each amplifier stage including:
1) a first level shift circuit for level shifting an input signal to generate a level shifted input signal, the level shifted input signal having a first bias level controlled by a first bias control voltage, the first bias control voltage varying as necessary with temperature and with respect to a process that fabricated the GaAs amplifier to hold constant the first bias level;
and
2) an amplifier for amplifying the level shifted input signal to generate an output signal, the output signal having a second bias level controlled by a second bias control voltage, the second bias control voltage varying as necessary with temperature to hold constant the second bias level.

1 more element

A precision GaAs amplifier, comprising:

a) a first level shift circuit for level shifting an input signal to generate a level shifted input signal, the level shifted input signal having a first bias level controlled by a first bias control voltage;
b) an amplifier for amplifying the level shifted input signal to generate an output signal, the output signal having a second bias level controlled by a second bias control voltage;
c) a first bias control circuit for generating the first bias control voltage, wherein the first bias control circuit comprises:
c1) a first operational amplifier outputting the first bias control voltage at a first operational amplifier output, the first operational amplifier having a first input coupled to a first DC reference voltage, the first operational amplifier having a second input;
and
c2) a first model circuit for generating the first bias level in response to the first bias control voltage, the first bias level being coupled to the second input of the first operational amplifier, the first model circuit modeling at least a portion of the first level shift circuit;
and
d) a second bias control voltage for generating the second bias control voltage.

5 more elements

Dependencies are inferred from the claim text.

Precision GaAs low-voltage DC amplifier

Life of this patent

Precision GaAs low-voltage DC amplifier

Life of this patent

Abstract

Claims20