Compact multiband slot-ring antennas.

摘要

In recent years, mobile communications have grown very quickly and become an important part of our everyday life. With the progress of small mobile units, the design of antennas is required to be small, lightweight and to have characteristics and performance properties, such as wide bandwidth, multi-frequency bands, and high gains. Slot-ring antennas fed by coplanar waveguide transmission line with open-circuited tuning stub are studied to find the design of a compact multiband antenna which satisfies the requirements for the respective bands.; A partial characterization of a square slot-ring antenna is performed. Varying each dimension of the slot-ring antenna gives a complete view of the most sensitive antenna physical parameters. It is especially found that changing the width of the top and bottom slots strongly affects the resonant frequency and the bandwidth. Based on the partial characterization results, the triple-band slot-ring antenna consisting of two square ring slots is designed. Two resonant modes for each operating band at about 900 MHz and 1900 MHz to cover the requirements of the GSM, DCS, and PCS systems are obtained by means of two radiating ring slots. Although triple-band operation is obtained, the antenna occupies a larger volume of 53.92 x 55.92 x 1.27 mm3. To reduce the volume, a CPW-fed meandered slot-ring antenna is designed. Using the 40 mm x 50 mm ground plane, the requirements of the GSM, DCS, and PCS systems are successfully achieved.; Using the shorted slot and the meandered slot to support circular polarization of GPS, SDARS, and WLAN systems, the compact quadruple-band circularly polarized slot-ring antenna is designed using the 35.88 mm x 35.88 mm ground plane. Circular and linear polarization characteristics are successfully achieved except for the WLAN band because the size of slot-ring for the WLAN band is very small compared to the CPW.