公开(公告)号：US20230327613A1

公开(公告)日：2023-10-12

申请号：US18330019

申请日：2023-06-06

Applicant: Socionext Inc.

Inventor： Takeaki WATANABE

IPC: H03F1/56 ,  H03F3/19

CPC classification number: H03F1/565 ,  H03F3/19 ,  H03F2200/451 ,  H03F2200/294

Abstract: A wireless communication circuit includes: an antenna; a transmitter circuit having an output amplifier outputting a transmission signal to the antenna; a receiver circuit having an LNA into which a reception signal from the antenna is input; and a matching circuit provided between the antenna and the input of the LNA. The LNA has a MOS input transistor receiving at its gate the reception signal from the antenna via the matching circuit, and includes a variable capacitance provided between the gate and source of the input transistor, the capacitance value of the variable capacitance being changed between the transmission time and the reception time.

公开(公告)号：US20170310350A1

公开(公告)日：2017-10-26

申请号：US15644578

申请日：2017-07-07

Applicant: SOCIONEXT INC.

Inventor： Koichiro TANAKA ,  Takeaki WATANABE

IPC: H04B1/16 ,  H03F3/19 ,  H03G3/30

CPC classification number: H04B1/16 ,  H03F3/19 ,  H03F2200/294 ,  H03F2200/451 ,  H03G3/3036 ,  H03G3/3052 ,  H03G3/3078 ,  H03G2201/202 ,  H04B1/30

Abstract: An AGC circuit for a radio receiver includes a detector converting a high frequency signal into a baseband signal. To reduce generation of a DC offset, the AGC circuit includes: a variable gain amplifier having an amplifier circuit and a high-pass filter, the amplifier circuit amplifying the baseband signal with a variable gain and the high-pass filter coupled to the amplifier circuit and having a cut-off frequency which is variable; a controller supplying a gain control signal; and a blocker temporarily blocking the high frequency signal. Using the block control signal, the controller causes the blocker to start blocking the high frequency signal, before the cut-off frequency of the high-pass filter is switched from high to low.