A Differential-Fed Rectangular Microstrip Patch Antenna with Dual-Band High Gain under Operation of TM01 and TM03 Modes

In this paper, a new design of a differential-fed microstrip patch antenna (MPA) with dual-band high gain is proposed under the operation of TM01 and TM03 resonant modes. Initially, three transverse slots are etched along the central line of the patch to interrupt the out-of-phase current of TM03 mode on the surface. Subsequently, by symmetrically introducing a set of shorting pins, the resonant frequency of TM01 mode is progressively turned up, and the radiation gain is hence effectively enhanced due to the enlarged patch size with respect to the operating wavelength. In addition, the antenna can be well matched in the desired 3.6 GHz and 5.9 GHz wireless communication network bands by properly adjusting the shorting positions of pins and length of slots. The simulated results demonstrate that at least 10 dBi realized gain can be obtained in both the lower and upper bands, and the radiation patterns in the two bands show agreeable beamwidths, while keeping antenna profile as low as 0.024 free-space wavelength.