A Review on Improved Design Techniques for High Performance Planar Waveguide Slot Arrays

Abstract

Planar waveguide slot arrays (WSAs) have been used since 1940 and are currently used as performing antennas for high frequencies, especially in applications such as communication and RADAR systems. We present in this work a review of the most typical waveguide slot array configurations proposed in the literature, describing their main limitations and drawbacks along with possible effective countermeasures. Our attention has been focused mainly on the improved available design techniques to obtain high performance WSAs. In particular, the addressed topics have been reported in the following. Partially filled WSAs, or WSAs covered with single or multilayer dielectric slabs, are discussed. The most prominent second-order effects in the planar array feeding network are introduced and accurately modeled. The attention is focused on the T-junction feeding the array, on the effect of interaction between each slot coupler of the feeding network and the radiating slots nearest to this coupler, and on the waveguide bends. All these effects can critically increase the first sidelobes if compared to the ideal case, causing a sensible worsening in the performance of the array.

Development of a Wideband Slotted Antenna Array with Low Profile and Low Sidelobe

“…Typically, a slotted waveguide antenna array is fed with a series structure [20], which is widely used due to its simpleness. However, when the size of the arrays becomes large, its long-line effect can dramatically affect its working bandwidth [21].…”

Design, Analysis and Fabrication of an Inside-Grooved Slotted Waveguide Array Antenna for HPM Applications

“…Additionally, due to the relatively large size of the transmit antenna, a gigawatt (GW) HPM signal can be achieved in S-band without breakdown [1], [2]. In an HPM system, the transmit antenna has a very crucial role [3], [4], [5]. It is an established fact that the efficiency of an entire HPM system depends upon its radiating antenna.…”

An Efficient Slotted Waveguide Antenna System Integrated with Inside-Grooves and Modified Gaussian Slot Distribution

“…In addition, a significant phase difference is realized between the radiating slots. The main beam direction is also frequency-dependent [5,11]. The most effective technologies to improve the radiation performance of slotted antennas include: electromagnetic band gap (EBG) structures [12], electromagnetic metasurface [13], frequency selective surface (FSS) [14], partially reflecting surface (PRS) [15], dielectric radome, and corrugated groove structures [16].…”