The design of integrated circuit microstrip hairpin-line band pass filters for short millimetre waves

Three-pole hybrid hairpin-line/half-wave parallel-coupled microstrip line band pass filters have been designed and evaluated. The filters were fabricated on 75 μm Z-cut quartz substrates and had a measured insertion loss of about 7.6 dB. The calculated insertion loss was 5.1 dB. The passband was centred at 129 GHz and the VSWR ranged from 1.06 to 1.53. The performance of the filter is compared with dielectric filters