Analysis of a Compact Dual/Single Band Tunable BPF for 5G/X-band Applications

Abstract

Currently, various microwave filter designs contend for the use in wireless communications. Among several microstrip filter designs, the tunable filter presents more advantages and better prospects for wireless communication applications, being compact in size, cost effective, and light in weight. These reconfigurable microwave filters can reduce the number of switches between the electronic components. The number of switches among the electronic devices can be decreased using tunable BPF. The tunable BPF is designed for X-band satellite communication applications as well as n77, n78, and n79 5G applications, and HSCH 3486 PIN diode is used to achieve the filter's tunability. An impedance bandwidth of 2.4 GHz and 2 GHz (fractional bandwidth of 25%) has been achieved with an S21 less than −1.5 dB, −2 dB and S11 of −22 dB and −31 dB at both the resonating frequencies. Semicircular cavity bandpass filter has been designed with the center frequency of 3.7 GHz. Switching between the two passbands has been obtained by attaching a PIN diode between the input and output feed lines.