Dual-Mode WR-3 Waveguide Filter with E-Plane Cut

In this paper, the design and realization of a wide-band dual-mode WR-3 waveguide filter is discussed. The filter is designed to have a center frequency of 291 GHz and a bandwidth of 37 GHz (FBW=12.7%). The dual-mode cavities are arranged to exploit the TE102 and TE301 modes. Each dual-mode cavity introduces one transmission zero (TZ) to the filter response, either below or above the passband. The filter proposed here is of fifth order while the TZs are placed nearly symmetrically close to the passband. Due to the utilized modes, the filter can be cut in the E-plane. A tolerance analysis is performed and the measurement results are discussed.