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A reconfigurable antenna using varactor diode for LTE MIMO applications

In this article, a mobile embedded antenna having tunable capacitance is proposed and the validity of the proposed solution was proved through design, fabrication, and measurement.The antenna can be applied to long‐term evolution (LTE) as well as DCS/PCS/WCDMA bands being currently used. Antennas for the 4G mobile service are required to expand its bandwidth so that it includes both LTE band and other service bands. However, it is hard to obtain low‐band characteristic due to the limited space for antenna in terminals. The proposed antenna consists of two planar inverted F antennas that are orthogonally arranged. Two radiators should be designed to have equal or enhanced isolation (S21) of lower than −15 dB. To meet this requirement, a varactor diode SMV2109 (skyworks corp.) was used to make the operation frequency of low‐band tunable. With the optimized parameters, the antenna was fabricated and measured and the results have been compared with the simulated result. The antenna satisfied with operation frequency and performance for both low‐band and high‐band, and measured performance of the antenna fabricated with optimized parameters is compared and analyzed with the simulation results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1141–1145, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27479