Stub‐loaded bent monopole antenna with independent frequency tuning capability for compact wireless USB dongles

In this article, compact monopole antenna with independent resonant frequency tuning capability is proposed.The antenna radiating patch consists of a simple, bent monopole element and an open stub. The bent monopole acts as a main radiator in 2.5 GHz band, whereas the open stub serves in 5.5 GHz band. A prototype of the proposed antenna was fabricated, and the reflection and radiation characteristics were measured to validate the antenna performances. Measured impedance bandwidths (VSWR < 2) exhibits dual-broadband resonances, which are 2.08–3.02 GHz (lower band) and 5.13–6.15 GHz (upper band), corresponding to 36.9 and 18.1%, respectively. Therefore, VSWR bandwidth of the proposed design covers not only the WiBro, WiMAX, Bluetooth, 2.4 GHz WLAN, S-DMB, but also the 5.2/5.8 GHz WLAN services. The peak gain was 5.76 dBi. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2548–2552, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27159