Novel Bi-Stable Switched Capacitors Using Phase-Change Materials

This letter presents a new type of switched capacitor based using Phase-Change Materials (PCM). A Metal-Insulator-Metal (MIM) capacitance is made using a PCM material as a top electrode, and a heater element as the bottom electrode. When the PCM material is amorphous, the capacitance is small, and when the PCM is conductive, the MIM capacitance is larger. A single element capacitor can be switched between 17.5 fF and 44 fF. 4-Bit capacitor can be controlled between 413.5 fF to 731.5 fF. $\text{Q}_{\text {s}}$ are extracted between 69.6 and 144.4 at 2 GHz for single element capacitor. Power handling has been measured showing stable behavior up to 24 dBm, limited by recrystallization of the material. The capacitance can withstand DC static voltage of 50V.