Design of a compact Microstrip Bandpass Filter for 2.4 GHz Applications

Microstrip bandpass filters are the core part of wireless communications. They help refine the signal and ensure that only the desired signal reaches the receiver. Microstrip bandpass filters are the core part of wireless communications. In this paper, a compact bandpass filter is designed using two rectangular open-loop resonators. The rectangular shape is used to achieve compact size and wide bandwidth performance. The substrate used is Rogers 6010 substrate with a thickness of 1.27 mm, a relative permittivity of 10.2, and an overall filter size of $11.55 \times 6.62 \mathrm{~mm}$. The resulting passband has a center frequency of 2.40 GHz, a bandwidth of 1.55 GHz, a fractional bandwidth (FBW) of 64.5%, a return loss of approximately -26.3 dB, and an insertion loss of -0.1 dB. The proposed filter was simulated and performance evaluated using HFSS (High Frequency Simulation Software). The resulting performance of the proposed filter makes it very desirable for Bluetooth and Wi-Fi applications (IEEE 802.11n).