Low profile printed antenna with a pair of step-loading for dual-frequency operation

Several techniques have been reported to reduce the size of a microstrip antenna having dual operating frequencies. A single low profile printed antenna which provides dual-band operation by having two-step slots loading embedded close to the radiating edge is presented. The ratio of the two frequencies can be well controlled by the aspect ratio of the step-loading dimension. Simulations performed on the designed antennas showed good dual band operation of f/sub 1/=1.575 GHz (GPS) and f/sub 2/= 1.8 GHz (GSM) with better than -10 dB achieved return losses. Satisfactory performance of dual matching are achieved when coaxial and EMC feeds are employed. The accuracy of the design is validated by using two different electromagnetic simulation softwares.