Compact dual-band bandpass filter using trisection hairpin resonator for GPS and WLAN applications

A compact dual-band bandpass filter using trisection hairpin-shape resonators has been designed and fabricated. Measured results are in good agreement with electromagnetic simulation results and verify that two central frequencies of the fabricated filter are located at about 1.57 GHz (GPS application) and 2.40 GHz (WLAN application). The measured return losses in both 1.57 and 2.40 GHz bands are higher than 16 dB while the measured insertion losses are about 1 dB in the two passbands. The circuit size of the proposed filter occupies only 26 times 26 mm (sime0.22lambda_g times 0.22lambda_g).