Filter Design Based on a New Tiered Circuit Board Process Transmission Line

In this paper, two filters are designed based on tiered circuit board (TCB) process transmission lines. The first filter is a low-pass filter with a cutoff frequency of 23 GHz. It exhibits an in-band return loss of less than −20 dB and an insertion loss of less than 0.2 dB, achieving an out-of-band suppression of 30 dB at 25 GHz. The second filter is a band-pass filter with an operational bandwidth ranging from 10.8 GHz to 12.4 GHz. It demonstrates an in-band return loss of less than −24 dB and an insertion loss of less than 0.2 dB, with out-of-band suppression exceeding 30 dB below 9.5 GHz and above 15 GHz.