POLYPHASE FILTER AND SINGLE SIDE BAND MIXER COMPRISING THE POLYPHASE FILTER

摘要

Disclosed is a four-phase filter.  The four-phase filter comprises four unit filters that each comprise a resistor and a main capacitor into which an input signal is inputted.  An input signal is supplied through a switch buffer into a subcapacitor provided in parallel with the main capacitor in each unit filter.  Shifting in an operating frequency band is made possible depending upon whether or not the switch buffer is in an output high impedance state.