Advanced Relay and Antenna Systems for Smart Networks

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balanced delay and power consumption.

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Chapter 10

Abstract

Antennas

Teddy Purnamirza

future RLSA antennas

1. Introduction

185

Radial Line Slot Array (RLSA)

Radial line slot array (RLSA) antenna was initially developed for satellite antenna receivers at a frequency of Ku-band. The success of this development inspired researchers to continue the study to other bands and other applications, such as Wi-Fi at 5.8 GHz. Wi-Fi applications need small antennas that lead to the diminution of RLSA antennas. Small-RLSA antennas experienced high reflection due to the small number of slots. One of the techniques that effectively eliminates the reflection was developed and named as extreme beamsquint technique. Several researches have successfully developed small-RLSA antennas by implementing this technique for Wi-Fi applications. Furthermore, for the future, it is possible to widen the researches to other frequencies and other features of RLSA antennas such

as multibeam, multiband, and diminution by cutting off RLSA antennas.

Keywords: RLSA antennas, extreme beamsquint, small RLSA, RLSA for Wi-Fi,

Radial line slot array (RLSA) antennas are a type of cavity or waveguide anten-

This chapter discusses briefly all about radial line slot array (RLSA) antennas, especially for the linearly polarized (LP)-RLSA antennas. Firstly, in Section 2, the review of RLSA antennas including the development of RLSA antennas, their applications, their development obstacles and the developed technique to overcome the obstacles are reviewed. Secondly, in Section 3, the theory of RLSA antennas is explained which includes how the antenna works and several equations to calculate antenna parameters. Thirdly, in Section 4, the mechanism of reflections in RLSA antennas, which is due to slot reflections and due to remaining power in antenna perimeter, is discussed. Fourthly, in Section 5, the theory of extreme beamsquint technique is also explained in detail. Lastly, in Section 6, the idea of future research in topic of RLSA antennas is briefly explained, including the idea of cutting off RLSA antennas to smaller size, multibeam RLSA antennas, utilizing background as

nas. These antennas were firstly developed for satellite receivers as an option besides parabolic antennas. Unlike parabolic antennas, RLSA antennas have an advantage of having feeders at the back of the antenna, so that the feeders do not block out incoming signals. The other advantage is their flat shape so that they are more aesthetic compared to parabolic antennas. Nowadays, RLSA antennas are developed for different frequency applications such as Wi-Fi, 5th G, etc.
