IMPEDANCE CONVERTER CIRCUIT, ANTENNA APPARATUS AND WIRELESS COMMUNICATION APPARATUS

摘要

Included are: an autotransformer circuit (25) that comprises a first inductor connected between a first port (P1) connected to a feeding unit side and a second port (P2) connected to an antenna side and that also comprises a second inductor connected between the second port (P2) and a third port (P3) connected to the ground; a first phase shifter (24) that has a first end connected to the first port (P1) of the autotransformer circuit (25); an inductor (23) that is series connected between a second end of the first phase shifter (24) and the feeding unit; and a capacitor (21) that is series connected to the inductor (23) and also series connected between the second end of the first phase shifter (24) and the feeding unit. Such arrangement achieves, in communication systems using discrete frequencies, respective matching states.