A novel suspended stripline bandpass filter using hybrid transmission line stepped impedance resonator

In this paper, a novel suspended stripline (SSL) bandpass filter using hybrid transmission line stepped impedance resonator (HTLSIR) is proposed. SSL has proven to be an excellent transmission-line system for realizing different types of filters. However, due to the effective permittivity being too close to unity, the size of the distributed elements is usually very large. The novel resonator introduced in this letter contains a section of hybrid transmission line which consist of the SSL and the microstrip line. The characteristics of the HTLSIR have been analyzed clearly. The novel SSL filter is designed, fabricated and tested. Both simulated and measured results are presented.