A series of curved microstrip antennae with defected ground structure for multiband are proposed，which are more smaller, conveniently conformal, wider radiation beam and suitable for WLAN terminal for different environment. The relation between the main geometry parameters and the antennas' characters are studied with the cavity model method and EM simulation, and the optimum size antenna is achieved later. If keeping the other parameters but increasing the curving angle α, the return loss is almost good at f=2.45 GHz, but poor at f=5.25 GHz and 5.8 GHz. After slight tuning the key parameters, these curved antennae all can work at f=2.45 GHz, 5.25 GHz and 5.8 GHz, and their patterns in the plane that is vertical to the curve axes become more wider or even omni-directional with the curving angle α increasing, which are verified by experiment, their measured gain are 2 dB--6.3 dB.
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