Design of a Simple Tunable/ Switchable Bandpass Filter

摘要

As the frequency spectrum gets crowded, with an increasing number of communication devices operating in a particular band, the role of the filter is becoming more and more critical. Since multimode portable terminals and tunable transceivers are starting to appear in the market, the importance of tunable filter is gaining momentum in the area of mobile communications. What is needed is a simple, cheap and small solution. Tunable filters greatly simplify the transceiver design and play a major role, especially in the area of wideband and multimode transceivers. This article reviews some of the fundamentals of the LC tuned resonator circuit and its implementation as a tunable or switchable band pass filter and therefore provides a feasible solution for the above applications in the UHF and VHF band.