A Single‐Feed Dual‐Band Frequency‐Reconfigurable Patch Antenna With Mode‐Selective Independent Tuning

A single‐feed dual‐band frequency‐reconfigurable patch antenna with mode‐selective independent tuning is proposed. Different varactor‐loaded tuning branches are introduced at the current‐sensitive regions of two orthogonal patch modes, enabling the lower and upper resonances to be controlled predominantly by different tuning paths within a shared radiating structure. The top‐loaded varactor branch mainly controls the x ‐directed TM 10 ‐like lower‐band resonance, whereas the side‐loaded varactor branches mainly tune the y ‐directed TM 01 ‐like upper‐band resonance. As a result, relatively independent dual‐band tuning is achieved while maintaining a low‐profile configuration and stable broadside radiation. The measured results demonstrate continuous tuning ranges from 2.39 to 3.10 GHz and from 3.09 to 4.95 GHz for the lower and upper bands, respectively, corresponding to relative tuning bandwidths of 25.8% and 46.2%. The peak realized gains are 5.2 and 8.42 dBi for the lower and upper bands, respectively.