Nippon Telegraph and Telephone Corporation

Kiyomitsu Onodera

Hideyuki Nosaka

Koichi Murata

Munehiko Nagatani

Shogo Yamanaka

Kimikazu Sano

Takatomo Enoki

Masahiro Muraguchi

A vector sum phase shifter includes a 90&#xb0; phase shifter () which generates an in-phase signal (VINI) and a quadrature signal (VINQ) from an input signal (VIN), a four-quadrant multiplier (I) which changes the amplitude of the in-phase signal (VINI) based on a control signal (CI), a four-quadrant multiplier (Q) which changes the amplitude of the quadrature signal (VINQ) based on a control signal (CQ), a combiner () which combines the in-phase signal (VINI) and the quadrature signal (VINQ), and a control circuit (). The control circuit () includes a voltage generator which generates a reference voltage, and a differential amplifier which outputs the difference signal between a control voltage (VC) and the reference voltage as the control signal (CI, CQ). The differential amplifier performs an analog operation of converting the control voltage (VC) into the control signal (CI, CQ) similar to a sine wave or a cosine wave.

Vector sum phase shifter, optical transceiver, and control circuit

A voltage generator () includes a resistor ladder including resistors (-) which divide a supplied voltage to generate a plurality of reference voltages, a resistor () provided between a power supply voltage (VCC) and one terminal of the resistor ladder, and a resistor () provided between a power supply voltage (VEE) and the other terminal of the resistor ladder.

Voltage generator, control circuit, vector sum phase shifter, and optical transceiver

A frequency conversion circuit having at least one transistor with an input terminal and an output terminal. A frequency signal to be converted or a local oscillator (LO) signal is input to the input terminal, and a converted frequency signal is output from the output terminal. A linear feedback circuit allowing at least a radio frequency (RF) signal and the LO signal to feed back is directly connected across the input and output terminals.

Frequency conversion circuit with linear feedback

Growing community of inventors

Kanagawa, Japan

Kiyomitsu Onodera