Wide-angle Scanning Phased Array Based on Long Slot Antenna

Much work so far has focused on the design of the phased array antennas (PAAs), across the frequency ranges from the meters to millimeter-wave bands. With the rapid development of PAAs, there is an urgent demand for wideband and wide-angle scanning performance. Naturally, the design of wideband and wide-angle scanning PAAs has been an important development trend, but as a matter of fact, the scanning angle of the PAAs is limited by many factors, among these factors, the major one is the mutual coupling between the PAA elements. To solve this problem, a long slot PAA with wide-angle scanning performance is investigated in this paper. This antenna element is based on the J. J. Lee's theory of the long slot antenna, in J. J. Lee's theory, the long slot antenna has a good wideband performance, but the wide-angle scanning performance need to be improved. In order to realize the wide-angle scanning performance, the proposed element uses two shorting pins to control the mutual coupling between the antenna unit cells. Meanwhile, two substrates, severing as the wide-angle impedance matching (WAIM) layers, are placed upon the antenna. Simulated results show that the designed array has an extremely good wide-angle scanning performance in X band. In E plane, the VSWR ≤ 2.5 while scanning to ±60° from 6.2 to 13.2 GHz (72% bandwidth), In H plane, the VSWR 2≤.5 while scanning to ±60° from 7.6 to 12.7 GHz (50% bandwidth). In the future work, an initial prototype array will be fabricated to validate the proposed concept.