Millimeter-wave Low-loss GaAs Bandpass Filter

The millimeter-wave filters fabricated using the GaAs IPD (Integrated Passive Device) process offer advantages such as low-loss, compact size, easy integration, high manufacturing precision, and suitability for mass production. Based on this technology, this paper utilizes full-wave simulation software to design a microstrip interdigitated bandpass filter with a passband ranging from 33GHz to 37GHz. The center frequency is set at 35.15GHz, featuring a 1dB difference passband spanning 32.60GHz to 37.71GHz and a maximum insertion loss of 1.97dB. Within the 32.68GHz to 36.91GHz frequency range, the return loss meets the requirement of being better than 15dB. Band-stop suppression reaches 37.2dB and 37.5dB at 28GHz and 42GHz respectively. The voltage standing wave ratio remains below 1.5 between 32.66GHz and 37.06GHz. The group delay peaks at the passband edges, measuring 0.37ns, indicating excellent linearity in the filter's phase response. These characteristics demonstrate that the filter has practical application value.