High permittivity substrate and dgs technique for dual-band star-shape slotted microstrip patch antenna miniaturization

Abstract

Three miniaturization techniques were combined in this work to achieve compact size while maintaining optimal performances of a dual-band star shape slotted Microstrip Patch Antenna (MPA) operating at 2.4 and 5 GHz resonant frequencies. High permittivity substrate and slot techniques were used for miniaturization and impedance matching improvement, while DGS technique was necessary for bandwidth enhancement and further miniaturization of the reference MPA. The miniaturized antenna shows a planar structure and occupies a very small area of 15.55 × 19.80 mm2 achieving patch size area reduction of 71.24% and overall size reduction of 75.42%. Respectable positive gains were maintained with radiation efficiency exceeding 83% and 68% at 2.4 GHz and 5 GHz, respectively. The reference and miniaturized MPAs were fabricated, then their performances were measured and compared to the simulated ones. The measured impedance bandwidths of the miniaturized MPA were around 38% and 13% at the two resonant frequencies, respectively, which confirm the originality and suitability of the miniaturized MPA for Wireless Local Area Network WLAN and ISM applications.