CMOS SWITCH FOR USE IN RADIO FREQUENCY SWITCHING AND ISOLATION ENHANCEMENT METHOD

摘要

PURPOSE: A CMOS switch for switching a high frequency band and switching isolation enhancing method are provided to enhance isolation features, thereby enhancing the operating features in a microwave band or a band whose frequency is higher than the microwave band. CONSTITUTION: A serial switching unit configures an SPDT switch by first and second CMOS switches(304,305). N-type MOS transistors(306,307) configure a switching isolation unit which electrically isolates a non selection output terminal from a common input terminal. An isolation enhancing unit(310) is connected to the first and second CMOS switches between two output terminals in parallel. The isolation enhancing unit forms a parallel resonant circuit with the parasitic capacitor of the serial switching unit. The isolation enhancing unit enhances the switching isolation about the serial switching unit. The SPDT switch switches a signal of a microwave band.