Compact Tunable Dual-Band Bandpass Filter For WiFi/WiMAX Applications

Abstract

The need for compact reconfigurable/tunable multiband RF front-end components is becoming an essential requirement for the different RF/MW systems especially with the significantly increasing development in the wireless systems industry. In this paper, fractal Hilbert structure is used to realize a design of compact varactor-based tunable dualband bandpass filter for WiFi/WiMAX applications. Both bandwidth and centre frequency can be tuned effectively; the centre frequency tuning range is 2.1/5.1 – 2.9/5.8 GHz covering the 2.3/2.4/2.5 and 5.8 GHz of the WiFi/WiMAX frequency bands. The bandwidth is also reconfigured to provide narrow passband responses up to 2% of fractional bandwidth. The simulation results show that the proposed design has many good features as the compact size, and the simultaneous control of both passbands through the same individual tuning circuit.