| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit for frequency adjustment means capable of adjusting a resonant frequency of an antenna within a desired range, and preferable for a radio communication device such as a portable phone.SOLUTION: A circuit for means of adjusting a resonant frequency of an antenna includes: a parallel resonance circuit having a variable capacitance circuit and a first inductance element; and a second inductance element connected to the parallel resonance circuit in series. The variable capacitance circuit includes a plurality of capacitance units connected in parallel, and the capacitance unit includes a switch connected to a capacitance element in series. |
