New synthesis of tunable filter and phase shifter used for phased array antennas applications

This paper present a new synthesis methodology of band pass filter used as phase shifter that allows to improve phased array system performances . This study, optimization and simulation of tunable bandpass filter centered at 2.45 GHz permit to design an efficient filter used as phase shifter based on coupled microstrip resonator loaded by varactor diodes. We have performed an electromagnetic simulation of improved 2.45 GHz RFID phased array antennas; we have implemented the synthesis methodology and we have used Momentum software to validate the obtained results. Good results were obtained in term of fractional bandwidth between 10% and 17% for our circuit and also a good dynamic range of phase shifting at operating frequency 2.45 GHz.