Christopher C Day

US Patent:

20190348955, Nov 14, 2019

Filed:

Jul 25, 2019

Appl. No.:

16/522169

Inventors:

Christopher John Day - Santa Rosa CA, US

International Classification:

H03F 1/32
H03F 3/193
H03F 3/21
H03F 3/45

Abstract:

A power amplifier circuit for broadband data communication over a path in a communication network can reduce or avoid gain compression, provide low distortion amplification performance, and can accommodate a wider input signal amplitude range. A dynamic variable bias current circuit can be coupled to a differential pair of transistors to provide a dynamic variable bias current thereto as a function of input signal amplitude. Bias current is increased when input signal amplitude exceeds a threshold voltage established by an offset or level-shifting circuit. The frequency response of the bias current circuit can track the full frequency content of the input signal, rather than its envelope. Gain degeneration can be modulated in concert with the bias current modulation to stabilize amplifier gain.

US Patent:

20190115876, Apr 18, 2019

Filed:

Sep 17, 2018

Appl. No.:

16/133282

Inventors:

- Norwood MA, US
Christopher John Day - Santa Rosa CA, US

International Classification:

H03F 1/32
H03F 3/213
H03F 3/24
H04B 1/04
H03M 1/00
H03M 1/06
H03M 1/18

Abstract:

Techniques for monitoring a distortion signal of a power amplifier circuit, where the output of a distortion monitoring circuit includes little or no fundamental signal and closely represents the actual distortion of the amplifier circuit of a wired communications system. The power amplifier circuit can generate a distortion feedback signal that does not affect the power amplifier's output power capability, e.g., no inherent loss in the fundamental output of the amplifier. That is, using a distortion monitor circuit, the power amplifier circuit can resolve a distortion feedback signal from the intended output signal of the output power amplifier circuit.

US Patent:

20180212573, Jul 26, 2018

Filed:

Jan 25, 2018

Appl. No.:

15/879947

Inventors:

- Norwood MA, US
Christopher John Day - Santa Rosa CA, US

International Classification:

H03F 1/32
H03F 3/19
H03F 3/45
H04L 25/08

Abstract:

A power amplifier circuit for broadband data communication over a path in a communication network can reduce or avoid gain compression, provide low distortion amplification performance, and can accommodate a wider input signal amplitude range. A dynamic variable bias current circuit can be coupled to a common emitter bias node of a differential pair of transistors to provide a dynamic variable bias current thereto as a function of an input signal amplitude of an input signal. Bias current is increased when input signal amplitude exceeds a threshold voltage established by an offset or level-shifting circuit. The frequency response of the bias current circuit can track the frequency content of the input signal. A delay in the signal path to the differential pair can phase-align the bias current to the amplification by the differential pair. A dynamic variable supply voltage can be based on an envelope of the input signal.