5.8GHz bandpass filter design using planar couple microstrip lines

Using microstrip lines to design a planar couple band-pass filter encounter some approximate errors due to the tolerance in PCB processing and coupling effects. Sometimes it causes unacceptable errors and it will be significant to reduce this error. In this paper, we use admittance inverters to design an 5.8GHz bandpass filter for Chebyshev attenuation response of 0.5dB. Modification of section lengths, widths and gaps by applying the iterative method used previously for synthesizing a coupler to compensate coupling effects and the tolerance in PCB processing. The simulation tool ADS and implemented filter measurements are performed to verify the adapted modified method and show very good results to our specified filter specifications. The method can be used to design any other bandpass filter.