الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Flexibility is becoming one of the most demanding aspects of any potential communication link. For example, direct broadcasting satellite (DBS) services will be greatly enhanced through the provision of service on the move. This market is very challenging because it requires a low cost, low profile antenna to be mounted on top of sport utility vehicles (SUVs) and minivans, furthermore, it has to cover the requirements in bandwidth (BW), polarization, and gain which became a difficult challenge. The main aim of this thesis was to produce a new array that will be capable of meeting the high challenge requirement for DBS to be available to be mounted on the moving vehicle. This thesis involved three main designs each design contains simulation, fabrication, and measurement, furthermore comparison between the achieved result and the last reported antenna which used the same technique. The first design concentrate on getting wide operating frequency with a circularly polarized (CP) behavior, furthermore low profile, complexity, cost, and stable gain over the operating BW. The proposed design consists of an 4×4 elliptical microstrip planer array which gets a superior result compared to the state-of-the-art CP antenna arrays. A novel double sequential feed (SF) a cavity back SIW feeding network contributed to achieve 19 dBi, 13% RLBW, and 20.7% ARBW Furthermore, getting a stable axial ratio over a wide beamwidth. In addition to that, the final antenna profile is 0.0184 λ. The second design takes a challenge to add the steering capability over the first design challenges. The traveling wave (TW) slotted SIW antenna was the best candidate to meet these requirements due to its excellent characteristics in beam steering capability, low size, and light weight but, the conventional TW slotted SIW antennas suffer from narrow BW. Consequentially, a new three slots configuration namely, two arms archimedean antenna, single-arm spiral antenna (monofilar), four concentric circulars have been investigated to treat this drawback. A 1x10 TW slotted SIW array, based on the first configuration which has the best result over the three configurations, has been designed, fabricated, and measured to achieve 35%, 13% RLBW, and ARBW. More, the directivity of the proposed antenna array is 14 dBi. Last designs are dealing with availability to receive the satellite signal during the vehicle moving. Firstly, a novel 1x8 two arms slotted spiral array antenna has been designed on polyvinyl chloride (PVC) substrate and conformed on a cylinder shape to provide an Omnidirectional pattern. But the phase difference due to the conformality didn’t allow to get a CP behavior. Secondly, a 2 × 8 two arms slotted spiral antenna array has been designed to form an octagon shape while each face contains two slots with spiral configuration. Many types of feeding have been studied (conventional feed, SF, switched feed) to conclude, that the switched feed is the best candidate where each two-face produce 45 ͦ× 45 ͦ pattern so, the 8-switched mode will cover 360 ͦ around the array with CP behavior and 12 dBi directivity.