Integration of 3D high-Q filters with monopole antennas

Seamless integration of 3D cavity filters with monopole antennas is presented. The typical 50-omega transition between the filter and antenna is eliminated to form a compact and efficient RF front end. A three-pole cavity filter integrated with a monopole antenna is demonstrated at X band. The center frequency and fractional bandwidth of the filter/antenna system are 10.07 GHz and 6.5%, respectively. The efficiency of the entire filter/antenna system is shown to be 93% in full-wave simulations. A prototype filter/antenna system is fabricated and measured. Excellent agreement between the simulated and measured results is observed. The integration approach presented herein can be used for other types of wire antennas depending on the application. (c) 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:921-925, 2014