Efficiency of a resistively loaded microstrip patch antenna

Resistive loading has been proposed as a method for improving the bandwidth of planar antennas. The paper assesses the impact of resistive loading on the performance of a microstrip patch antenna. While resistively loaded antennas offer the benefit of large improvements in antenna bandwidth, it is illustrated through the use of theoretical developments, numerical simulations, and experiment, that the efficiency of some of the antennas reported in the literature is unacceptably low.