Patent ID: 8878619

Claim:
A variable phase amplifier circuit comprising: a phase splitter circuit, wherein the phase splitter circuit receives an input differential signal pair, and wherein the phase splitter circuit outputs a first and a second differential signal pair in response to receiving the input differential signal pair, and wherein the second differential signal pair has a phase that is different than a phase of the first differential signal pair; a first variable gain amplifier circuit coupled to the phase splitter circuit, wherein the first variable gain amplifier circuit scales the first differential signal pair by a first scale factor in response to receiving the first differential signal pair; a second variable gain amplifier circuit coupled to the phase splitter circuit, wherein the second variable gain amplifier circuit scales the second differential signal pair by a second scale factor in response to receiving the second differential signal pair; and a summation circuit coupled to the first and the second variable gain amplifier circuits, wherein the summation circuit receives a first and a second scaled differential signal pair from the first and the second variable gain amplifier circuits respectively, and outputs a modified differential signal pair in response; wherein the first variable gain amplifier circuit comprises a limiter stage, wherein the limiter stage limits the amplitude of the first scaled differential signal pair.