Experimental study of new planar filter without using cross-coupled effect

Abstract

The paper presents two novel miniaturised band-pass microstrip filters without using the conventional cross-coupled effect. Using the meandering technique and the direct feed structure, two transmission zeros located close to the pass-band are generated. As a result, the selectivity and out-of-band rejection of the filters are significantly increased. A fractional bandwidth of about 4.3 centred at 6.75GHz and an insertion loss of 3.81dB have been realised. The design is verified by experimental results and relatively good agreement between the simulated and measured results have been obtained.