Radiation from ground plane photonic bandgap microstrip waveguides

This paper presents an analysis of radiation of photonic bandgap (PBG) microstrip structures along with the pass and stopband behavior. Simulations are compared with measurements performed on a PBG microstrip waveguide with circular slots in the ground plane, designed to have a broad stop-band centered around 10 GHz. Radiation can be significant at some frequencies for a microstrip PBG and should be considered when designing filters, harmonic terminations and antenna feeds. Radiation of -3.4 dB was measured at 15 GHz relative to the input power in the passband. Measurement data agree well with simulations.