1-D microstrip PBG band-pass filter without etching in the ground plane and with sinusoidal variation of the characteristic impedance

In this paper a new type of band-pass filter based on (1-D) microstrip photonic band-gap (PBG) is presented. The band-pass filter is a serial connection of two periodic structures with sinusoidal variation of the characteristic impedance in function of the position along the microstrip line. It is based only on the modification of the shape of the microstrip line, without etching in the ground plane. Band-pass is simulated, realized and measured for three different frequencies only by scaling. Agreement between simulation and measurement is very good.