S-Band Microstrip Bandpass Filter Design Based on New Approach to Coupling Coefficients Calculation

In this paper, a new approach to bandpass filter design, based on coupling coefficients calculation, introduced in [1], is experimentally verified. S-band (2.7-3.1 GHz bandwidth) microstrip bandpass filters of several four-resonator structures for pre-selectors of active phase array radar systems are designed, produced and measured. A conventional parallel-coupled filter is produced and measured for comparison. Measurement results confirm good performance of used approach.