Developing Inter-Digital Band Pass Filter using Suspended Substrate Stripline Technology In K-Band

Abstract

In this paper, we present a new design methodology for constructing a bandpass filter based on an inter-digital structure. The electrical model of the filter was developed based on the concept of the self and mutual electric capacitances of the coupled transmission lines forming the basic structure of the filter.

After that, the proposed electrical model was built using the suspended substrate striplines technology, which allows obtaining wide bandpass filters. The physical dimensions of the transmission lines that make up the filter were reached after a series of calculations that depend on the method of trial and error and compared with the calculated values from Maxwell's capacitance matrix. Then, a simulation was conducted to study the filter performance according to the obtained dimensions. It was found that the simulation results achieve the desired ones in terms of the center frequency ( ), Fractional Band Width ( ), and the bandpass ripple factor ( ).