IMPEDANCE MATCHING CIRCUIT, ANTENNA DEVICE, AND COMMUNICATION TERMINAL APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide an impedance matching circuit that impedance-matches a feeder circuit and an antenna element over a wide frequency band, and an antenna device and a communication terminal apparatus therewith.

SOLUTION: An impedance matching circuit 101 includes: a first transformer circuit TC1 including a first transformer T1; and a second transformer circuit TC2 including a second transformer T2 and resonating at a frequency different from a resonant frequency of the first transformer circuit TC1. A primary coil L11 of the first transformer T1 and a primary coil L21 of the second transformer T2 are electromagnetically coupled, and a secondary coil L12 of the first transformer T1 and a secondary coil L22 of the second transformer T2 are electromagnetically coupled. The second transformer circuit TC2 includes inductors LS1 and LS2 as a phase shifter for making the phase of a signal propagated through the second transformer circuit TC2 different from the phase of a signal propagated through the first transformer circuit TC1.

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