Diagnosis techniques for planar antennas using iterative algorithms: Application to radial line slot antennas

Radial Line Slot Antenna (RLSA) [1] is an attractive candidate for high gain and low cost circular polarized antennas. During the last decades, there has been an increasing interest in RLSA due to several reasons: the first of them is their simple structure, which makes them suitable for low cost mass production. Furthermore, their low profile allows them to be easily adapted to any surface. Finally, a high efficiency can be achieved with this type of antennas because their conductor losses are very low. Traditionally, pencil beam RLSA applications include receiving direct broadcast satellite (DBS) systems [2] or local area networks. These antennas have been designed to have uniform amplitude [3]. Later, RLSA have been utilized for higher frequencies (millimeter bands) and other applications that do not require maximum gain, but arbitrary shaped patterns, such as isoflux beams or designs with controlled side lobe levels [4]. During the last years, different research groups have been improving the design techniques [3-4] or analysis techniques [5]. However, for these new applications the manufacturing errors can be very important for changing the radiation pattern. Therefore, an accurate source reconstruction technique can be very important to improve the designs. A source reconstruction technique for slot array antennas was presented in [6], and the theory and results for RLSA are presented in this conference. By exploiting the information about the positions and the polarizations of slots to the Gerchberg-Papoulis iterative algorithm, the field on the slots is accurately reconstructed. The proposed technique is applied to the source reconstruction of a K-band radial line slot antenna (RLSA), and measured results are presented, compared with the designed data. Of course, this algorithm can be also be used for other kind of antennas as patch arrays.