Patent ID: 8385475
Filing Date: 2013-02-26
Classification: H03D,H03K

Abstract:
1. A circuit for producing multiple switching control signals for a harmonic rejection mixer from multiple phases of a digital local oscillator signal, wherein the circuit comprises: a first waveform combiner having a waveform logical combination circuit arranged to generate from the multiple phases of the digital local oscillator signal at least one switching control signal by logical combining two from the multiple phases of the digital local oscillator signal, the first waveform combiner including an output to output the at least one switching control signal to the harmonic rejection mixer; and a second waveform combiner having a waveform logical combination circuit arranged to generate from the multiple phases of the digital local oscillator signal at least one first switching control signal by logical combining one from the multiple phases of the digital local oscillator signal with a predetermined signal having a static logical value, the second waveform combiner including an output to output the at least one switching control signal to the harmonic rejection mixer; wherein a schematic topology of the first and the second waveform combiners are fully symmetrical to each other; wherein the first waveform combiner includes the logical combination circuit of the first waveform combiner and a copy of the logical combination circuit from the second waveform combiner, the copy of the logical combination circuit being configured as a dummy combiner circuit to logically combine one from the multiple phases of the digital local oscillator signal with a static logical value; and wherein the second waveform combiner includes the logical combination circuit of the second waveform combiner and a copy of the logical combination circuit from the first waveform combiner, the copy of the logical combination circuit being configured as a dummy combiner circuit to logically combine two from the multiple phases of the digital local oscillator signal.