Patent ID: 9231559
Filing Date: 2016-01-05
CPC Classification: H03H

Claim Text:
1. A vector sum circuit for producing a radio frequency (RF) output at a selectable phase offset, comprising: an RF input configured to receive a differential pair RF input; a quadrature network configured to produce an additional pair of RF inputs whose phase is advanced 90 degrees (90°) with reference to the differential pair RF input, thereby producing four RF input signals offset at 0°, 90°, 180° and 270°; for each RF input signal, a set of three cascodes, each cascode comprising a plurality of NPN transistors, wherein an emitter electrode of each NPN transistor in each cascode is commonly connected to a corresponding RF input; a first output terminal connected to a collector electrode of each NPN transistor in a first cascode of the set of three cascodes for each RF input; a second output terminal connected to a collector electrode of each NPN transistor in a second cascode of the set of three cascodes for each RF input; and a voltage rail connected to a collector electrode of each NPN transistor in a third cascode of the set of three cascodes for each RF input, wherein a first output from said first output terminal and a second output from said second output terminal combine to define an output signal that is a vector addition of said four RF input signals.