Mitsubishi Electric Corporation

Ryota Komaru

Masatake Hangai

Shintaro Shinjo

Koji Yamanaka

Kazuhiko Nakahara

Yoshifumi Kawamura

Kei Fukunaga

Tetsunari Saito

A phase shifter includes: a first all-pass filter; a second all-pass filter; a first switching switch to provide a signal to either one of the first all-pass filter and the second all-pass filter; and a second switching switch to select the signal having passed through the first all-pass filter or the signal having passed through the second all-pass filter, wherein the first all-pass filter includes two inductors and three capacitors, and the second all-pass filter includes two inductors and three capacitors, or the first all-pass filter includes three inductors and two capacitors, and the second all-pass filter includes three inductors and two capacitors, and element values of elements included in the first all-pass filter and element values of elements included in the second all-pass filter are determined by impedance at which impedance matching is achieved, a frequency of the signal, and a variable.

Phase shifter comprising selectable first and second all-pass filters, where the all-pass filters include capacitors and inductors of determined values to achieve impedance matching

A high-frequency power amplifier is configured in such a way as to include an input matching circuit, an amplifying element, an output matching circuit, a coupling circuit, a detection circuit, and an output terminal, and in such a way that either the input matching circuit or the output matching circuit has an active element, the detection circuit receives a signal outputted by the coupling circuit and outputs a control voltage into which the detection circuit converts the signal to the active element, and the active element changes the impedance of the active element in accordance with the control voltage outputted by the detection circuit, thereby changing the power of a signal outputted by either the input matching circuit having the active element or the output matching circuit having the active element, to change the power of a signal which the coupling circuit outputs to the output terminal.

High-frequency power amplifier

A high-frequency switch includes: a first transistor connected to an input terminal and a first output terminal; a second transistor connected to the first output terminal; a third transistor connected to the second transistor and grounded; a resistor connected to a connection between the second and third transistors and grounded; a switching circuit switchable between a state in which the switching circuit allows passage of a transmitted/received signal between the input terminal and a second output terminal and a state in which the switching circuit cuts off the transmitted/received signal; and a control unit to control the first, second, and third transistors and the switching circuit. At the time of reception, the control unit brings the switching circuit into the state in which the switching circuit cuts off the transmitted/received signal, places the first and third transistors in an on-state, and places the second transistor in an off-state. At the time of transmission and reception with an automatic gain control operation, the control unit brings the switching circuit into the state in which the switching circuit allows the passage of the transmitted/received signal, brings the first and third transistors in an off-state, and brings the second transistor in an on-state.

High-frequency switch

There are provided: a first capacitor connected between first and second input/output terminals; a second capacitor connected between the first input/output terminal and a third input/output terminal; a first inductor having one end connected to the first input/output terminal; a second inductor having one end connected to the second input/output terminal and another end connected to another end of the first inductor; a third inductor having one end connected to the first input/output terminal; a fourth inductor having one end connected to the third input/output terminal and another end connected to another end of the third inductor; a first transistor having a drain terminal connected to said another ends of the first and second inductors and a source terminal that is grounded; and a second transistor having a drain terminal connected to said another ends of the third and fourth inductors and a source terminal that is grounded.

Growing community of inventors

Tokyo, Japan

Ryota Komaru