NON-RECIPROCAL CIRCUIT ELEMENT, COMPOSITE ELECTRONIC COMPONENT AND COMMUNICATIONS EQUIPMENT

摘要

PURPOSE: To realize satisfactory impedance matching and to attain miniaturization and low price by providing a port for connecting a matching capacity to a central conductor in parallel and a port for connecting the matching capacity to the central conductor in series. CONSTITUTION: An isolator uses matching capacities C1 to C3 of nearly the same size and of the same capacity value, and a port P1 serially connects the capacity C1 to a central conductor 2 to markedly lower its input/output impedance compared with other ports P2, P3. The input impedance of the port P1 is constituted to match with the output impedance of the amplification element of the output stage of a power amplifier to be connected with the port 1 to directly connect the low impedance of the amplification element without an output matching circuit. Thus, an output power quantity amplifier can be miniaturized and the increase of an insertion loss and narrowing of a band occurring, in the case of providing a matching circuit, are prevented to reduce a loss and to widen a band.