Effect of substrate parameters on planar photonic bandgap (PBG) structure

Recently a lot of research has been carried out on photonic bandgap structures in the microwave regime. In this work, the authors investigate the performance of a microstrip transmission line on different substrates. We have used substrates with: (1) the same dielectric constant value but different height; (2) the same height but different dielectric constant value. We investigate the S-parameter performance of a standard 50 /spl Omega/ transmission line on different substrates in terms of passband 10 dB RL-BW, 20 dB rejection bandwidth, the deviation of centre of the stopband frequency from the designed frequency and ripple height in the passband.