A loop-type ground antenna with wide-band operation is proposed for USB dongle applications. The solution for improving the bandwidth is based on a resonant feeding circuit that includes both an inductor and a capacitor. By choosing an appropriate ratio of the inductance to the capacitance, the impedance bandwidth (VSWR < 2) is 21.8% at 2.2 GHz, sufficient bandwidth to cover both the WCDMA and WiMax frequency bands.

A triple-band ground radiation antenna is proposed that can cover the 1575 MHz global positioning system (GPS) band and the 2.45 and 5.5 GHz WLAN bands, within a 6 × 9 mm ground clearance. The proposed triple-band antenna is comprised of two inner rectangular loops, each enclosed by a larger outer loop. Each band can be adjusted for impedance matching by means of respective matching circuits. The −10 dB return loss bandwidths were simulated to be 17, 130 and 1000 MHz. Measurements indicated that sufficient bandwidth and good radiation performance were also achieved.