Patent ID: 7756491
Filing Date: 2010-07-13
Classification: H03F,H03H,H04B

Abstract:
1. A phase shifter, comprising: a plurality of variable gain elements, each variable gain element configured to receive one of a plurality of quadrature input signals, each quadrature input signal having a phase that is shifted with respect to each other input signal, wherein each variable gain element comprises a switching transistor and a gain control transistor coupled to the switching transistor, the gain control transistor configured to receive the control signal, and wherein the gain control transistor controls the amount of current flowing through the gain control transistor when the switching transistor is active as a function of the gate-source voltage of the gain control transistor; a control signal supplied to each variable gain element, the control signals defining a phase shift; and a signal combiner configured to combine an output of each of the plurality of variable gain elements, the signal combiner providing a phase shifted output signal.