Adaptive high-frequency filter and an adaptive high-frequency duplexer and a radio apparatus using the same

摘要

PROBLEM TO BE SOLVED: To solve the conventional problem in an adaptive high-frequency filter that full coping with the deterioration in the characteristics of radio equip ment caused by disturbing signals or spurious signals, generated from the sur rounding radio environment or the frequency configuration inside the radio equipment cannot be provided.;SOLUTION: In this adaptive high-frequency filter, one or a plurality of voltage-controlled variable frequency resonance elements are used, each of which is constituted by electrically connecting a resonance element to a voltage- controlled variable impedance element and electrically connected to a control section. A signal monitor section adaptively generates a control signal, based on the information on the oscillation frequency of the internal oscillator of the radio equipment, loaded with the filter and adaptively variably controls the frequency characteristic of the filter using a control voltage signal generated by means of the control section, based on the control signal.;COPYRIGHT: (C)2003,JPO