Renesas Electronics Corporation

Kenji Toyota

Masakazu Mizokami

Tomohiro Sano

Yoshikazu Furuta

Kazuhiko Hikasa

A semiconductor apparatus, includes a common mode detector circuit that receives alternating current (AC) signals in a common mode.

Semiconductor apparatus and radio communication apparatus

A semiconductor apparatus includes a common mode detector circuit that receives differential alternating current (AC) signal; and a detector circuit.

A semiconductor apparatus that can detect the amplitude level of harmonics is provided. A semiconductor apparatus includes a common mode detector circuit that detects alternating current (AC) signals in a common mode, and a detector circuit that detects the amplitude level of an even-order harmonic output from the common mode detector circuit. The common mode detector circuit combines the AC signals being differential signals in common mode, thereby cancelling out odd-order harmonics to obtain direct current and even-order harmonics. The detector circuit detects the amplitude level of the even-order harmonics from a signal obtained by the common mode detection, and outputs the detected amplitude level.

A transmitter has a transmission modulator including first and second modulators, a phase comparator and a controller. First and second non-inverted local signals supplied to the modulators are set to have a predetermined phase difference. In a calibration action for reducing carrier leakage, the phase comparator is supplied with the first or second local signals, and carrier signals leaking at an output of the transmission modulator. The controller keeps changing the ratio of DC biasing currents to paired transistors of each modulator until the predetermined phase difference is detected with the phase comparator. When the predetermined phase difference is detected, the controller stops changing the ratio of DC biasing currents. The chip footprint of a transmitter on the direct up-conversion (DUC) architecture is reduced, and carrier leakage owing to local signals supplied to the transmission modulator are decreased.

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Tokyo, Japan

Kenji Toyota