Computer aided design of dual-mode elliptic and Butterworth filters in Ku-band

Dual-mode filters are important in the design of modern satellite communication systems. In such systems, where small size and light weight are highly critical, elliptic filters are thus far the best choice, owing to their lowest order among other filter configurations for a given set of performance specifications. In this paper, we present a computer aided design (CAD) approach for dual-mode elliptic and Butterworth filter design. The proposed CAD approach is applied to the design of two circular cavity filters operating in 14.6-15.6 GHz band, and the resulting designs are implemented in hardware. Both analysis and design are performed using a new electromagnetic (EM) based in-house computer program and a full-wave solver i.e. Ansoft HFSS. Measurements are carried out using Agilent´s network analyzer. It is shown that the frequency responses of the designed filters obtained from simulations and measurements show a good match.