Tunability improvement of tunable capacitors using the finger patterned electrode

In this work, tunable capacitors by enhancing fringe electric (E)-field in order to improve their tunability have been presented. Tunable capacitors were fabricated on a quartz substrate employing a low-loss and high-tunability para-ferro electric multi-layer thin film dielectric. Effects of finger patterns enhancing fringe electric-fields are analyzed in terms of effective capacitance and tunability, compared to the conventional tunable capacitors. At 25V and 3GHz, the maximum tunability of the finger-patterned capacitor with a line width of 2 μm is 38% that is 5.8% higher value than that of the convention one with the same electrode area.