A Compact Low-Pass Filter with Simple Structure and Sharp Roll-Off

In this paper a compact low pass filter (LPF) with desirable figure of merit (FOM) and sharp roll-off is designed. The cut-off frequency of the designed filter is 3 GHz. The designed filter has a sharp transition-band of 0.88 GHz, from 3 to 3.88 GHz with corresponding attenuation levels of -3 and -60 dB, respectively. Also, the proposed filter has wide ultra stop-band from 3.8 GHz to 10 GHz with 20 dB suppression level. The dimensions of the proposed LPF is 0.13λg × 0.058λg, which shows excellent size reduction.