SWITCHED TRANSFORMER

摘要

PURPOSE: A variable transformer is provided to be used for a matching circuit of a power amplifier requiring a plurality of load resistors by controlling first side inductance and second side inductance or inductance of first and second sides. CONSTITUTION: A variable transformer includes a first side transmission line(1102) and a second side transmission line(1103). The first side transmission line connects a plurality of inductors, connects its one end to a first output end of a differential amplifier(1101) and the other end to a second output end of the differential amplifier. The second side transmission line connects a plurality of the inductors and is separated from the first side transmission line. The second side transmission line is formed with the same pattern as the first transmission line and forms the other end as an output end. The first side transmission line and the second side transmission line include switching devices(1106,1107) varying inductance of the inductor formed in the each transmission line.