Tuning Range and Efficiency Optimization of a Frequency-Reconfigurable Patch Antenna

This letter studies the design tradeoffs for a classical frequency-reconfigurable microstrip patch antenna using tuning varactors. A solid framework to maximize the tuning range and efficiency of the antenna is proposed and experimentally validated. The method can be generalized to different antennas using varactors as tuning mechanism. The study shows the importance in simultaneously choosing the number of tuning devices as well as, importantly, their distances to obtain the appropriate capacitance range for an optimal design.