A novel antenna of Planar Antenna Array with Separated Feed (PAASF) with lower side lobe pattern and higher antenna gain was designed. The unique property of this antenna design is that instead of fabricating all together in the same plane, the antenna's feeding network is separated from the antenna radiating elements (the patches) by an air gap distance. In this paper, the characteristics radiation pattern of two different radiating structures have been studied and compared. The first antenna configuration ("Structure 1") is a 16-element planar antenna array whose feed line is printed on the same plane as the radiating elements. The second ("Structure 2") is a 16-element planar antenna array whose feed network is separated from the radiating elements by an air gap. Both antennas are designed at 5.8 GHz. The PAASF technique is enables to reduce the unwanted spurious effects from the feed line. From the comparison results, it obviously shown that the "Structure 2" is given better sidelobe to mainlobe ration of-11.9dB while "Structure 1" only-5.35dB. In this structure, not only improvement is achieved in the sidelobe reduction pattern, but also better performance in term of the antenna gain. The antenna gain generated by "Structure 2" of 11.78dB is higher compared to 8.539dB generated by "Structure 1". Since some of the transmission line is placed to another board in PAASF, the size of that antenna become smaller compare to "Structure 1". Finally, in order to proof the validity of the antenna design, the simulated results (CST 2008) have been compared with measurements, and good agreement has been found.
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