US 11,990,873 B2
Radio-frequency power-amplifying element
Yasunari Umemoto, Nagaokakyo (JP); Shaojun Ma, Nagaokakyo (JP); and Shigeki Koya, Nagaokakyo (JP)
Assigned to Murata Manufacturing Co., Ltd., Kyoto-fu (JP)
Filed by Murata Manufacturing Co., Ltd., Kyoto-fu (JP)
Filed on Feb. 5, 2021, as Appl. No. 17/168,904.
Claims priority of application No. 2020-026220 (JP), filed on Feb. 19, 2020.
Prior Publication US 2021/0257973 A1, Aug. 19, 2021
Int. Cl. H03F 1/30 (2006.01); H03F 3/19 (2006.01); H03F 3/21 (2006.01)
CPC H03F 1/302 (2013.01) [H03F 3/19 (2013.01); H03F 3/211 (2013.01); H03F 2200/451 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A radio-frequency power-amplifying element, comprising:
a substrate; and
a first amplifier circuit and a second amplifier circuit that are disposed on the substrate, wherein
the first amplifier circuit includes at least one bipolar transistor,
the second amplifier circuit includes a plurality of bipolar transistors,
the at least one bipolar transistor of the first amplifier circuit and the plurality of bipolar transistors of the second amplifier circuit each include
a collector layer on the substrate,
a base layer on the collector layer,
an emitter layer on the base layer,
an emitter mesa layer on the emitter layer,
an emitter electrode connected to the emitter layer through the emitter mesa layer, and
a base electrode disposed on the base layer and connected to the base layer,
the emitter mesa layer and the base electrode of the at least one bipolar transistor of the first amplifier circuit do not overlap each other when viewed in plan,
the emitter mesa layer and the base electrode of each of the plurality of bipolar transistors of the second amplifier circuit do not overlap each other when viewed in plan, and
a minimum spacing between the base electrode and the emitter mesa layer of at least one of the plurality of bipolar transistors of the second amplifier circuit is greater than a minimum spacing between the base electrode and the emitter mesa layer of the at least one bipolar transistor of the first amplifier circuit.