A design solution for the 4-8 GHz bandpass interdigital cavity filter

Abstract

Ultra-high frequency band filters with a bandwidth of up to GHz (UWB) are an indispensable component in radio communication and reconnaissance systems. With the requirement of ultra-wide frequency band, high barrier loss and slope, the topology selection, design and simulation techniques, and manufacture technology need to be carefully researched to achieve desired parameters and quality of the filter. This paper proposed a solution to design and manufacture an ultra-wide band (4¸8 GHz) Interdigital cavity filter. CST software is used in the design and simulation to achieve dimensional accuracy and desired parameters. The filter operates at center frequency f₀ = 6 GHz with a bandwidth of FBW = 4 GHz, barrier loss of -40 dB and slope of 10 dB/100 MHz. The design and simulation results are optimized by the software, the post-manufactured filter is measured, evaluated and achieved the required criteria.