Patent ID: 7421259
Filing Date: 2008-09-02
Classification: H03D

Abstract:
1. A radio frequency (RF) mixer, comprising: a. an input transistor pair, configured to receive a baseband signal and a local oscillator (LO) signal; b. a plurality of submixers coupled to each other in parallel, configured to mix the baseband signal and individual phase-shifted LO waveforms, each submixer in the plurality of submixers being driven by a single phase-shifted LO waveform and having a polarity that prevents cancellation of signals output from each other submixer in the plurality of submixers; and c. a tail current source configured to supply power, wherein the plurality of submixers share the input transistor pair and the tail current source, and wherein the LO signal is divided into a plurality of individual phase-shifted LO waveforms that create a piecewise linear waveform approximating the LO signal when combined, and a phase difference between any two time-adjacent individual LO waveforms in the plurality of individual LO waveforms is approximately equal to a phase difference between any other two time-adjacent individual LO waveforms in the plurality of individual LO waveforms.