Dielectric waveguide filter with low profile and low-insertion loss

A novel type of dielectric waveguide filter has been developed for future mobile communications. The filter is characterized by planar input/output terminals as well as a practical low-profile structure. Fabricated filters, a three-pole with 2.5-mm height and a two-pole with 0.6-mm height, exhibit low-insertion losses of 0.8 and 1.3 dB, respectively, for the bandwidth of 200 MHz at 5.8-GHz center frequency.