Patent ID: 8803564
Filing Date: 2014-08-12
Classification: H03J,H03K

Abstract:
1. A tunable capacitance control circuit comprising: a metal-insulator-metal (MIM) capacitor; a plurality of field effect transistor (FET) switches connected in series with the MIM capacitor; and a control unit applying switch on or off control signals to each of the gate terminals of the plurality of FET switches, wherein the control unit outputs the control signals allowing only one of the plurality of (n) FET switches to be switched on and the remaining (n−1) FET switches to be switched off, thereby obtaining a desired tunable capacitance value, and wherein in obtaining the desired tunable capacitance value (Cmim), the control unit adjusts and obtains a “Cmim2” value and a Coff value according to the switch off the FET by the following Equation,