In this article, the band-pass filter (BPF) of steppedimpedance hairpin (SIH) design having a very wide stopband performance was proposed. The filter composed of two SIHs connected by a narrow bended microstrip with the latter's middle point shorting to the ground through a via hole. A long narrow coupled microstrip was used to couple I/O signal to/from the SIH resonators. The filter operated at a quarter-wavelength resonance condition was built for WLAN IEEE 802.11b/g (2.4/2.45 GHz) applications. The filter's upper stopband had its frequency range measured from 2.76 to 23.08 GHz with the criterion of the signal rejection levels greater than 20 dB. The stopband's upperend is over 9.5 f0 (with central frequency, f0 1/4 2.44 GHz). Experiment was conducted for the circuit validation and a good agreement was observed between the measurement and simulation.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering