TWO-FREQUENCY SWITCH, DEVICE USING TWO-FREQUENCY ANTENNA IN COMMON, AND MOBILE RADIO COMMUNICATION EQUIPMENT FOR TWO-FREQUENCY BANDS USING THE DEVICE

摘要

A high frequency switch used for a mobile communication apparatus, such as, a portable telephone or the like is provided. The dual band switch may be in an ON or an OFF state in two bands. The dual band switch may comprise a series circuit including a PIN diode and a compensation circuit. The compensation circuit may be formed having at least two series resonance points and one parallel resonance point. The circuit arrangement allows the impedance of the compensation circuit, which is capacitive at low frequency close to a direct current, to become inductive after a first series resonance point, so that a parasitic capacitance of the diode may be canceled in a first band. The impedance of the compensation circuit may also become inductive after a parallel resonance point and the following series resonance point, so that a parasitic capacity of the PIN diode may be canceled in a second band.