Mediatek Singapore Pte. Ltd.

Mediatek Corporation

Ian Tseng

Ming-Da Tsai

Chien-Cheng Lin

Yangjian Chen

Chien-Wei Tseng

Bernard Mark Tenbroek

A quadrature transmitter includes a first and second matched transmitter path. Each transmitter path receives respective sets of quadrature baseband signals. At least one local oscillator port receives respective sets of quadrature LO signals. Mixer stage(s) respectively multiply the sets of quadrature baseband signals with the respective sets of quadrature LO signals to produce a respective output radio frequency signal. A combiner combines the output RF signals. The first set of quadrature signals is a substantially 45&#xb0; phase shifted version of the second set of quadrature signals; and the first set of quadrature LO signals is a reverse substantially 45&#xb0; phase shifted version of the second set of quadrature LO signals. A baseband error correction circuit corrects a phase error between the quadrature baseband signals at baseband and a LO error correction circuit corrects a phase error between the quadrature baseband signals at a LO frequency.

Quadrature transmitter, wireless communication unit, and method for spur suppression

A harmonic-rejection mixer apparatus includes a mixing circuit and a combining circuit. The mixing circuit receives mixes an input signal and a first local oscillator (LO) signal to generate a first output signal, and mixes the same input signal and a second LO signal to generate a second output signal, wherein the first LO signal and the second LO signal have a same frequency but different phases. The combining circuit combines the first output signal and the second output signal, wherein harmonic rejection is at least achieved by combination of the first output signal and the second output signal.

Phase-rotated harmonic-rejection mixer apparatus

A quadrature transmitter is described that comprises: a first transmitter path and a second transmitter path that are matched. Each transmitter path comprises: at least one input arranged to receive respective first or second sets of quadrature baseband signals; at least one local oscillator, LO, port configured to receive respective first and second sets of quadrature LO signals; at least one mixer stage coupled to the at least one input and configured to respectively multiply the sets of quadrature baseband signals with the respective first or second sets of quadrature LO signals to produce a respective output radio frequency, RF, signal; and a combiner configured to combine the output radio frequency signals of the first transmitter path and the second transmitter path. The first set of quadrature signals is a substantially 45&#xb0; phase shifted version of the second set of quadrature signals; and the first set of quadrature LO signals is a reverse substantially 45&#xb0; phase shifted version of the second set of quadrature LO signals.

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Taipei, Taiwan

Ian Tseng