摘要 |
PROBLEM TO BE SOLVED: To provide a switching circuit with which higher frequency and larger power amplification is possible than with a push-pull amplifier using a switching element whose semiconductor material consists of silicon or gallium arsenide, by switching an inductance element with a single switching element, and to provide an envelope signal amplifier with the switching circuit. SOLUTION: The switching circuit 33a is provided with: an input side transmission line in which gates of n transistors (FET) M1, M2 to Mn using silicon carbide (SiC) as the semiconductor material are cascade-connected via a coil L1; and an output side transmission line in which drains of the respective transistors M1, M2 to Mn are cascade-connected via a coil L2. The transistors Mm (m is an integer from 1 to n) are sequentially turned on by a PWM signal which is given from an input end 331 to be propagated on the input side transmission line, and current which flows in the drain of the transistors Mm is added to current which is propagated in a direction toward an output end 332 on the output side transmission line. COPYRIGHT: (C)2011,JPO&INPIT |