Abstract    A set of hybrid microstrip patch and semi-circular cavity antennas is introduced. The semi-circular cavity is implemented using Half-mode Substrate Integrated Waveguide (HMSIW) technique. Different shapes of patch include rectangular, semi-circular and equilateral triangular are excited using proximity effect by the circular SIW cavity at its TM010 mode of operation. The whole structures have been excited using an inset microstrip line that leads to facility of planar circuit integration. The inherent limited bandwidth of the conventional microstrip patch antenna and SIW cavity-backed slot antenna is improved about 6% to 9.5% depending on the type of the patch using the proposed structure. Additionally, the proposed hybrid antenna enhances the antenna gain by about 1.5 dB. Meanwhile, the proposed hybrid antennas are made on a single-layer substrate has a low fabrication cost using printed circuit board (PCB) process. Three hybrid antennas are numerically and experimentally investigated. A comparative study between the three different structures contains gain, bandwidth, cross polarization level (CPL) and Front to Back Ratio (FTBR) is presented.

Keywords    Hybrid antenna, microstrip patch, SIW cavity

چکیده    در این مقاله یک مجموعه از آنتن­های ترکیبی شامل محفظه نیم دایره­ای با فناوری موجبر مجنمع شده در زیر لایه و پچ مایکرواستریپ معرفی شده است. محفظه نیم دایره­ای توسط فناوری موجبر مجتمع شده در زیر لایه نیم مود (HMSIW) پیاده­سازی شده است. شکل­های مختلف از پچ شامل مستطیلی، نیم دایره ای و مثلثی متساوی الاضلاع با استفاده از اثر مجاورت توسط حفره SIW دایروی در مود کاری TM010، تحریک شده­اند. کل ساختار توسط یک خط مایکرواستریپ تحریک شده که این امر مجتمع شدن ساختار با مدارهای مسطح را تسهیل می­کند. محدودیت ذاتی پهنای باند آنتن­های پچ مایکرواستریپ و شکاف­های تحت حمایت حفره SIW حدود 6% تا 5/9% بسته به نوع پچ به­کار رفته، بهبود می­یابد. بعلاوه، آنتن ترکیبی پیشنهادی حدود dB 5/1 بهره را افزایش داده است. در حالی­که آنتن ترکیبی پیشنهادی با هزینه ساخت کم توسط فرآیند برد مدار چاپی (PCB) روی یک زیر لایه ساخته شده است. سه آنتن ترکیبی به صورت عددی و تجربی بررسی شده­اند. یک مقایسه بین این ساختارها از نظر بهره، پهنای باند، سطح قطبش مخالف و مقدار FTBR ارائه شده است.

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