Computer-aided tuning of GSM base-station filters - experimental results

This paper describes a novel technique for the computer-aided tuning of filters and duplexers employed in GSM base stations. The procedure is based on the derivation of the characteristic polynomials of the filters through a modified implementation of the Cauchy method, suitable for a subsequent synthesis of the coupling matrix associated to the measured response. The extracted coupling matrix at each step of the procedure is compared to the goal one (obtained from a perfectly tuned unit) and suitable indications are derived for the regulations of the tuning elements of the filter. An experimental example confirms the effectiveness of proposed procedure.