Patent ID: 6424227
Filing Date: 2002-07-23
Classification: H01L,H03F

Abstract:
A monolithic balanced radiofrequency power amplifier comprising:a semiconductor substrate; a first transistor formed over said substrate; a second transistor formed over said substrate; a transformer having a first conductive spiral coupled to said first transistor and residing over a first portion of said substrate so that positive current flows in a first rotational direction, a second conductive spiral coupled to said second transistor and residing over a second portion of said substrate so that positive current flows in a second rotational direction which opposes said first rotational direction, a center tap between said first and second conductive spirals, a third conductive spiral positioned over said first portion of said substrate, and a fourth conductive spiral positioned over said second portion of said substrate; and a source of direct current biasing for said first and second transistors coupled to said center tap of said transformer.