High-order UWB bandpass filter using cascading e-shape microstrip structure

Summary form only given, as follows. One type of E-shape microstrip structure is composed of half wave length hairpin resonator loaded by a grounded stub at its middle. For the first time, using an equivalent circuit for this structure, high-order UWB bandpass filter design technique is presented based on cascading E-shape microstrip structures. Two third-order UWB bandpass filter are designed, simulated, fabricated and measured. These filters have compact sizes approximately smaller than 3.5mm × 3.2mm × 0. 4mm. The theoretical and measured results show excellent agreement. It is observed that UWB bandpass filters with the E-shape microstrip structure are capable of offering campact circuit size, flat group delay, good selectivity, excellent wideband rejection and low insertion loss.