HIGH-FREQUENCY CIRCUIT, HIGH-FREQUENCY PART, AND MULTIBAND COMMUNICATION DEVICE

摘要

Provided is a high-frequency circuit used by a multiband-compatible radio device for switching the connection between an antenna and a transmission/reception circuit in accordance with signals of a plurality of communication systems.  The high-frequency circuit includes: a single-pole multiple-throw switch circuit having an FET switch circuit arranged between a common port connected to the antenna side circuit and a plurality of single ports connected to the transmission/reception circuit; and a first rectification circuit connected to the common port.  The first rectification circuit includes: a first inductance element connected in series to a signal path between the antenna and the common port; and a first capacitance element connected to the antenna side of the first inductance element and grounded.  The first inductance element induces the impedance of the single-pole multiple-throw switch circuit when the single port side is viewed from the antenna side.  The first capacitance element adjusts the impedance matching between the antenna side circuit and the transmission/reception circuit.