US 12,451,846 B2
High-frequency, multistage, low-noise amplifier
Takaaki Yoshioka, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 17/760,179
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Jul. 27, 2020, PCT No. PCT/JP2020/028728
§ 371(c)(1), (2) Date Aug. 4, 2022,
PCT Pub. No. WO2022/024189, PCT Pub. Date Feb. 3, 2022.
Prior Publication US 2023/0066275 A1, Mar. 2, 2023
Int. Cl. H03F 1/42 (2006.01); H03F 1/56 (2006.01); H03F 3/195 (2006.01); H03F 3/24 (2006.01); H03F 3/68 (2006.01)
CPC H03F 1/42 (2013.01) [H03F 1/565 (2013.01); H03F 3/195 (2013.01); H03F 3/245 (2013.01); H03F 3/68 (2013.01); H03F 2200/267 (2013.01); H03F 2200/294 (2013.01); H03F 2200/36 (2013.01); H03F 2200/451 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A high-frequency, multistage, low-noise amplifier comprising:
a high-frequency input terminal;
a high-frequency output terminal;
a multistage circuit provided between the high-frequency input terminal and the high-frequency output terminal and including two or more amplifiers connected in series to each other, each amplifier including an input matching circuit, a transistor, and an output matching circuit;
a stabilizing circuit provided in each of at least two of the amplifiers of the multistage circuit and including a bandpass filter and a resistor connected in parallel to each other; and
a band-rejection filter provided between the at least two of the amplifiers and eliminating a frequency lower than an operation frequency of the amplifier,
wherein the stabilizing circuit and the band-rejection filter are provided between an output terminal of the transistor of the amplifier and the output matching circuit or provided in the output matching circuit, and
the closer to the high-frequency input terminal a respective bandpass filter among the bandpass filters is, the lower a resonance frequency of the respective bandpass filter is, with respect to the bandpass filters included in the stabilizing circuits.