Waveguide-Slot Array Antenna Designs for Low-Average-Sidelobe Specifications

Abstract

This paper discusses the design, analysis, and development of waveguide-fed planar slot arrays to achieve low-average side lobe specifications, as may arise in radiometer applications. Such antennas may be required to meet strict average sidelobe levels in different angular regions, and low average return loss over a specified bandwidth. In addition to Elliott's design technique, we used a Moment-Method analysis program, Ansoft's HFSS code, and results of tolerance studies using Monte Carlo simulations to meet the design objectives. Comparisons of simulated results and experimental results are also presented.

Effect of the Feeding T-Junctions in the Performance of Planar Waveguide Slot Arrays

“…Each subarray is fed by a feeding waveguide, fed in turn by a T-junction. The position of the T-junctions is between the ninth and tenth radiating guides for subarrays 1 and 2, and between the fifth and sixth radiating guides for subarrays 3 and 4 (the array structure is therefore 9-5, 5-9, [5][6][7][8][9].…”

“…Waveguide slot arrays provide a high gain, mainly due to the reduced losses in the feeding structure, and a very good polarization purity, either linear [5], [6] or circular [7], [8]. These are the main reasons pushing for their widespread use, especially in the X-band and beyond [9]- [12]. A considerable mechanical strength and the absence of coupling with nearby electronic or RF circuits are further advantages of slot arrays.…”

“…The main feeding point of such an array can be realized in many different ways, for example using coupling slots between a feeding guide and the radiating guides [10], with one feeding guide for each subarray. The feeding guides are, in turn, fed with coupling slots by a main waveguide feeding network [9] (see Fig. 1).…”

Ka-Band Slot-Microstrip-Covered and Waveguide-Cavity-Backed Monopulse Antenna Array

“…They are 0.6 mm in width and 3.2 mm in length, and the approximate offset value from the waveguide centreline is calculated at 34 GHz using the equivalent circuit mode or termed Elliott's method [20,21]. Elliott's method has been successfully used for waveguide slot antenna arrays [22][23][24][25][26][27][28], although it yields the offset value to be approximately effective only. In order to get more accurate offset value and fully account for the coupling effect, it is necessary to optimize the monopulse antenna array by fullwave simulation.…”

Ka band slot array antenna for interferometric synthetic aperture radar topographic mapping mission

“…Each subarray consists of 8 radiating waveguides with 10 radiating slots in each. Centered inclined coupling slots are used to excite each radiating waveguide from an orthogonal feed waveguide which is in turn excited by a center-fed input coupling slot in a manner similar to the arrays in [2].…”