Design of Ka-Band Tunable Filters in Rectangular Waveguide with Constant Bandwidth

In this paper the design of rectangular waveguide filters in Ka-band with constant bandwidth is discussed. Only the cavities are assumed to be tuned, while the couplings must be dimensioned in order to get constant the bandwidth in the tuning bands. The tuning elements are implemented by means of dielectric rods driven by a single stepper micro-motor. As a result, all the rods are assumed to have the same penetration in the cavities for each tuning band. The design of a filter with 500 MHz bandwidth tuned in the band 29-31 GHz is presented, together with the preliminary simulation results.