Design of Monopole Antenna Integrated with an CSRR-SIW band-pass Filter using a Cascaded Approach

In this paper, a butterfly-shaped monopole antenna is integrated with a CSRR-SIW band-pass filter using a cascaded approach. Initially, the design of the monopole antenna was suggested and studied. The bandwidth of this monopole antenna was extended by inserting a L-Shaped DGS into the partial ground plane, where the extended bandwidth ranges from 2.49 to 6.53 GHz . The design of an SIW band-pass filter based on extended split rectangular CSRRs is suggested to operate within the Wi-Fi 5 GHz band. The proposed band-pass filter operates at 5.47 GHz with -3dB fractional bandwidth of 13.52% (i.e., 5.07 GHz -5.81 GHz). The observed insertion loss is around 0.24 dB and the return loss is 32.23 dB. To validate the SIW-CSRR filter performance, it was cascaded with the previous wideband monopole antenna to cover the 5 GHz WI-Fi band. The resulting filtenna successfully achieves the primary goal of sharply defining the operating frequency band while maintaining good impedance matching within that band. Moreover, the suggested filtenna provides an omnidirectional radiation pattern over the desired band with a realized gain of 2.93 dBi.