Patent ID: 6127894
Filing Date: 2000-10-03
Classification: H01L,H03F

Abstract:
A high frequency shunt feedback amplifier comprising:a substrate having a ground plane;a high frequency hybrid amplifier circuit located on the substrate, the amplifier circuit comprising an amplifier mounted in a transistor cavity of the substrate and having an input terminal and an output terminal; anda feedback path that electrically couples the amplifier input terminal and the amplifier output terminal, such that the feedback path includes(a) a first direct current blocking device,(b) a second direct current blocking device,(c) a first electrically resistive coupling element coupled between the amplifier input terminal and the first direct current blocking device, and(d) a transmission line circuit path electrically coupled between the first and second direct current blocking devices at a first end and electrically coupled to the ground plane at a second end, such that the second direct current blocking device is electrically coupled to the amplifier output terminal;wherein the transmission line circuit path is selected such that it produces a feedback signal that is approximately ninety degrees out of phase with an amplifier input signal for high frequencies of interest.