Patent ID: 11855601

Abstract:
The present invention relates to a high-frequency semiconductor device. A conventional high-frequency semiconductor device including an input second-order harmonic matching circuit has such a problem that gain decrease occurs. In a high-frequency semiconductor device (100) of the present invention, two adjacent unit transistor cells (7) and (8) are connected to one input second-order harmonic matching circuit (19) provided on an upper surface of a semiconductor substrate (1). The input second-order harmonic matching circuit (19) includes a first capacitor (13), a first inductor (14), a second capacitor (15), and a second inductor (16). The first capacitor (13) and the first inductor (14) resonate at the frequency of a fundamental wave, and each of impedances as seen by input electrodes of the two unit transistor cells (7) and (8) is short-circuited at the frequency of a second-order harmonic.