Switch Controlled 4 bands Band pass Filter with Two E-shaped SIRs

A novel 4-bands microstrip band pass filter (BPF) is proposed here, which consisted of two E-shaped microstrip Stepped-Impedance Resonators (SIR) with different sizes. Each of one E-shaped SIR is presented as a set of the dual pass band. Consequently, four pass bands are centered at 3.30 GHz, 4.83 GHz, 5.825GHz, and 8.65 GHz with the fractional bandwidth of 6.7%, 9.1%, 8.4%, and 8.2% can be obtained by the proposed design. The working frequency band can be changed by switching the two E-shaped SIRs. Due to its rich operation band resources, it can be used for 5G base station systems and other applications.