https://jjcit.org/paper/118 5G HAIRPIN BANDPASS FILTER 10.5455/jjcit.71-1597459727 Sahar Saleh,Widad Ismail,Intan Sorfina Zainal Abidin,Mohd Haizal Jamaluddin,Mohammed H. Bataineh,Asem S. Alzoubi Hairpin bandpass filter (HPBF),Harmonics suppression,5G,Reconfigurable antenna,Cognitive radios (CRs),HFSS 20 3193 1034 15-Aug.-2020 28-Sep.-2020 13-Oct.-2020 In this paper, Hairpin Bandpass Filter (HPBF) is designed, simulated and fabricated at two 5G low-frequency bands: 3.7 GHz- 4.2 GHz and 5.975 GHz-7.125 GHz. This filter will be a part of our 5G narrowband/ Ultra Wide Band (UWB) reconfigurable antenna project that plays a significant role in the recent wireless networks, such as Cognitive Radios (CRs). Through the two frequency bands, the filter resulted in good matching and transmission responses with enhanced bandwidth. The measured reflection coefficient of the proposed HBPF, S11 is <-10 dB and <-11.66 dB through 3.45 GHz – 4.25 GHz and 5.62 GHz – 7.6 GHz, respectively. However, the transmission coefficient, S12 is around-1.5 dB and – 1.17 dB at the center frequencies FC = 3.75 GHz and 6.61 GHz, respectively. In this paper, the High-Frequency Structure Simulator (HFSS) software is used to carry out the simulation. The full-wave simulation results are validated with the hardware measurements.