Compact Tunable (Generic) Sub-λ Meta-Filter for X/Ku Band: Control and Reconfigurability of Central Frequency, Bandwidth and Order

A compact tunable X/Ku-band waveguide meta-filter based on locally resonant metamaterials (LRMs) is presented. The structure uses a composite pin–pipe waveguide in which the heights and number of resonant pins are mechanically adjusted to jointly control the central frequency f0, bandwidth w, and filter order n. True order reconfigurability from three to two to one pole is obtained on the same hardware, while a meta-port provides independent tuning of the external quality factor Qefor proper matching in each state. Full-wave simulations and measurements validate the concept and demonstrate one-octave tuning in the single-resonator case with low insertion loss.