The University of Electro-Communications

Campus Create Co., Ltd.

Yoichiro Takayama

Kazuhiko Honjo

Ryo Ishikawa

A concurrent-type multiband amplifier (or a dual-band amplifier) which amplifies multiband signals concurrently using a plurality of (N) amplifier circuits which each independently amplify signals in a plurality of (N) frequency bands. An n-th (n=any of 1 to N) amplifier circuit is provided with a circuit for blocking signals in frequency bands other than the n-th frequency band so as to amplify and output only the n-th frequency band signal. The n-th amplifier circuit is designed so as to consist of its input/output impedance matching circuit for the n-th an amplifier element at the n-th frequency band.

Dual-band amplifier

An amplifier circuit operating at a fundamental angular frequency &#x2022;, includes: a transistor which is represented by an equivalent circuit which includes: an equivalent output current source, a drain-source capacitor as a parallel parasitic capacitor to an output node of the equivalent output current source, and a drain inductor as serial parasitic inductor connected between the equivalent output current source and a drain output node; a harmonic frequency processing circuit which includes an input node connected with the drain output node and an output node; a resonant circuit section provided between the output node of the harmonic frequency processing circuit and a ground node and comprising (2n+1) resonators which have resonance frequencies different from each other; and a load resistance provided in a back stage of the harmonic frequency processing circuit. The resonance frequencies of the (2n+1) resonators are coincident with frequencies of (n+1) poles and n zeros formed between the drain output node and the ground node in the transistor when the output node of the harmonic frequency processing circuit is short-circuited to the ground node.

Growing community of inventors

Tokyo, Japan

Yoichiro Takayama