Source/Drain to Gate Capacitive Switches and Wide Tuning Range Varactors

摘要

A two-terminal capacitive circuit element 100 includes a MOS transistor including a source 126 and drain 127 separated by a body region 131, and a gate 105 separated from the body 129 by a gate insulator layer 110, and a bypass capacitor 125. The gate node (port2; 115) is AC grounded through the bypass capacitor 125 and the source 126 and drain 127 are tied together (port-1; 120). By toggling the transistor on and off using an appropriate gate to body voltage, the capacitance of the capacitive circuit element 100 between port-1 and port-2 significantly changes.