Optimization of a Compact Frequency- and Environment-Reconfigurable Antenna

This paper presents a novel ultra-compact (0.17 × 0.17 × 0.05 wavelengths) reconfigurable antenna equipped with shunt switches at the edges of the radiating elements; in addition to wide-band frequency-reconfigurability, the antenna can also adapt to different environments. The challenging task of designing a compact antenna for multi-band and multi-environment operation is tackled by a hierarchical optimization process consisting of the genetic algorithm (GA) and local search for geometry optimization, and exhaustive search for computation of the optimum switch patterns for a fixed geometry. Both tunability and environment robustness were confirmed in simulation and measurements on a proof-of-concept prototype where switches were simulated by soldering. Numerical analysis of the impact of commercial MEMS devices is also reported, including a case study of practical interest: a compact antenna that can operate at different locations around a simplified model of a laptop PC without performance degradation.