FDTD analysis of dielectric-embedded electronically switched multiple-beam (DE-ESMB) antenna array

The design procedure, finite-difference time-domain (FDTD) modeling, and experimental measurements for a novel dielectric-embedded electronically switched multiple-beam (DE-ESMB) antenna array are presented in this paper. Size reduction of a parasitic switched monopole antenna was accomplished by embedding the array in a cylindrical rod of L6G nylon with a relative permittivity /spl epsi//sub r/=4.4. Dielectric-embedded and free-space prototypes of a nine-element ESMB antenna array were modeled and experimentally characterized. Experimental measurements and numerical results are in good agreement. The measured return loss for the nine-element embedded antenna was less than -25 dB at 2.32 GHz. An overall volume reduction of 80% and footprint reduction of 50% was achieved. Adaptive simulated annealing with FDTD was used to optimize the 17-element DE-ESMB array, achieving a return loss of less than -10 dB across the 2.4 GHz to 2.5 GHz ISM band.