OFF-STATE ISOLATION ENHANCEMENT FOR FEEDBACK AMPLIFIERS

摘要

A feedback amplifier having an improved feedback network including two cross coupled switches that isolate the amplifier from extraneous undesired electrical signals present in a system or network when the amplifier is turned off (i.e., in an off-state). The cross coupled switches interconnect two feedback paths of a feedback network to enable out-of-phase differential signals to be summed and effectively canceled. Further, the feedback amplifier provides on-stage advantages to enable different amplifier characteristics and parameter to be selectively engaged by turning on or turning off certain feedback networks.

主权项

1. A differential feedback amplifier comprising:
a positive first line input corresponding to a negative first line output; a negative second line input corresponding to a positive second line output; a first feedback path extending from the first line output towards the first line input; a second feedback path extending from the second line output towards the second line input; wherein the first feedback path includes a first switch and a second switch, wherein the first switch couples the first feedback path to the positive first line input and the second switch cross couples the first feedback path to the negative second line input; and wherein the second feedback path includes a third switch and a fourth switch, wherein the third switch couples the second feedback path to the negative second line input and the fourth switch cross couples the second feedback path to the positive first line input.