Conformal Filtering Patch Antenna with Dual Independently Tunable Radiation Nulls

A conformal, compact, and flexible patch filtering antenna with independently tunable radiation nulls is presented. By etching open-ended split-ring resonator (SRR) slots and meandered slots on a conformal microstrip patch, two independently controllable radiation nulls are introduced to enhance band-edge selectivity. The antenna is implemented on a flexible substrate, maintaining stable filtering performance and radiation null controllability under conformal conditions. The prototype is designed to operate at 2.37 GHz and conforms to a cylindrical surface with a radius of 70 mm. Two radiation nulls are achieved at 2.10 GHz and 2.47 GHz, respectively. The antenna exhibits an average in-band gain of over 7.1 dBi and out-of-band suppression exceeding 20.5 dB. The proposed design is particularly suitable for conformal antenna systems in smart helmets and unmanned aerial vehicles (UAVs)/robotic platforms, where low-profile integration onto curved surfaces and enhanced interference rejection are essential.