Application of combined electric- and magnetic-conductor ground planes for antenna performance enhancement

This paper investigates the application of three different ground planes for antenna performance enhancement. They are the conventional perfect electric conductor (PEC), the perfect magnetic conductor (PMC), and their combination. A half-wavelength dipole in free space is considered as the reference case, and its performance over these ground planes is investigated and compared. It is shown that by using a combined PMC-PEC ground plane, one can achieve a better performance. Next, a microstrip patch antenna is considered as the source and is placed over a high-impedance surface (HIS) or an artificial magnetic conductor (AMC). Here too, adding a PEC ground plane on the periphery of the HIS or AMC improves the antenna gain significantly. As well, the superiority of AMC ground planes, consisting of grounded dielectric slabs loaded with periodic metallic patches without shorting pins (vias), is investigated in detail. Simulation results show that use of such artificial ground planes can enhance the microstrip patch antenna gain and bandwidth remarkably. These enhancements are confirmed by measurement, and high gains of 10.4 dBi and input impedance bandwidths of 28% are measured.