Mobile-phone antennas must become increasingly multiband in order to accomplish their many functions. In response to these trends, researchers have proposed a design method that provides quarter-band operation for the following bands: GPS (1565 to 1585 GHz), UMTS/W-CDMA (1920 to 2170 MHz), Industrial Scientific Medical (ISM; 2400 to 2483.5 MHz), and SDMB (2630 to 2655 MHz). This work is credited to Byung-chan Jang, Che-young Kim, and Jeung-keun Park from the Depatment of Electrical Engineering and Computer Science at Korea's Kyungpook National University.
This planar, meander-line antenna comprises three branch strips. To achieve miniaturization, the folded metal plates of the three branches were mounted on a dielectric-coated groundplane. For multiband operation, the sectional antenna for each band was designed, combined, and trimmed. The antenna's return loss of 10 dB was calculated by the HFSS simulator from Ansoft Corp. (www.ansoft.com). See "Quarter- Band Internal Antenna Design Using Three Branches for GPS, UMTS/WCDMA, ISM, and SDMB Band Operation," Microwave and Optical Technology Letters, May 2008, p. 1227.