A compact tunable microwave bandpass filter based on liquid crystal

Abstract

In this Letter, with the application of liquid crystal (LC) an electrically tunable microwave filter has been designed, manufactured, and characterized. The proposed compact filter has been realized on a particularly configured cavity which was constructed with low cost invertedmicrostrip structures and conventional resonance structure. By applying low square-wave (1KHz) voltages, low power consumption is involved. The filter responses have been allocated at k-band of microwave frequency at which band many communications and radar applications applied. The proposed filter occupies a compact area of 19 mm 3 17 mm only. The measured results have shown that the proposed filter realized the central frequency changing from 15.5 GHz to 16.5 GHz continuously with bias voltages changing between 0 and 10 V.ABSTRACT: Wireless power transfer (WPT) in near-field communication (NFC) using current-controlled multi loops with a loaded capacitance is demonstrated in this work. The proposed multi loops antenna