US 12,273,077 B2
Load detection circuit and amplifier circuit
Ikumi Tokuda, Kyoto (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Kyoto (JP)
Filed on Apr. 28, 2021, as Appl. No. 17/242,474.
Claims priority of application No. 2020-080300 (JP), filed on Apr. 30, 2020.
Prior Publication US 2021/0344307 A1, Nov. 4, 2021
Int. Cl. H03F 1/52 (2006.01); H03F 1/56 (2006.01); H03F 3/195 (2006.01)
CPC H03F 1/565 (2013.01) [H03F 3/195 (2013.01); H03F 2200/105 (2013.01); H03F 2200/318 (2013.01); H03F 2200/423 (2013.01); H03F 2200/451 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A load detection circuit comprising:
a first detection circuit that is capacitively coupled with a signal transmission line, and that is configured to output a first signal, the signal transmission line connecting an output port of a RF amplifier and a load;
a second detection circuit that is inductively coupled with the signal transmission line, and that is configured to output a second signal; and
an arithmetic circuit configured to generate a load impedance detection signal by performing a subtraction operation on the first signal and the second signal.