Design of a Bandpass Filter Using Microstrip Hairpin Resonators

The implementation of devices developed in microstrip technology is commonly found in radio frequency and microwave communications, where it has evolved with a variety of applications, among which fast response filters stand out. In this study, we present the design and behavior of a microstrip Hairpin bandpass filter for a frequency of 2.45 GHz, with a bandwidth greater than 100 MHz, and an insertion loss (S-21) higher than -3 dB. The filter was designed and modeled with the COMSOL (R) Multiphysics software using, the specific radio frequency module, where S-11 and S-21 parameters were simulated. This filter was made on an FR4 substrate, and its dispersion parameters were measured with a vector network analyzer (VNA), to compare its results with the one obtained in the multiphysics model. Finally, a bandpass filter was achieved for 2.45 GHz, with a bandwidth of 389 MHz, and an insertion loss (peak) of -2.1 dB.