Wideband Circularly Polarized DRA Array Fed by Printed Ridge-gap Waveguide Technology for Millimeter-Wave Applications

With the increasing wireless systems requirements for higher data rate, wider bandwidth, and miniaturized wireless terminals, more attention has been directed towards the millimeter-wave band. The unlicensed frequency band of 60 GHz has attracted attention in recent years for indoor or point-to-point communication systems. Another band of interest is the 28 GHz band, this band offers several gigahertzes of bandwidth and has been identified recently in Europe, USA, China and Korea for 5th generation (5G) wireless systems. Communication systems will be able to provide multi-gigabit real time throughput if they operate within these bands with large bandwidths, thus allowing for real time video and multimedia transmissions in high definition. One significant limitation of the millimetre-wave band is its higher free-space path loss that is proportional to the square of the frequency of the radiated signal. Another challenge with the design of mm-wave antennas is how to design a simple, low cost, low loss, and efficient feeding mechanism to avoid the use of bulky and expensive waveguides conventionally used at millimetre-wave band. The proposed work is intended to resolve the two aforementioned challenges, by developing a wideband circularly-polarized dielectric resonator antenna (DRA) array excited with ridge-gap waveguide technique at 28 GHz with the possibility to extend and scale the whole design to work at 60 GHz band as well. The use of the high-gain DRA array is expected to combat the high free-space losses encountered at high frequencies. Moreover, the use of the recently-developed printed (i.e., microstrip) ridge-gap waveguide technology to excite the DRA array is considered to be a low-loss, low-cost, and simple-to-fabricate feeding mechanism. Fortunately, the printed ridge-gap waveguide (PRGW) feed used here is integrated with microstrip edge connector via a transition structure to avoid the use of bulky and costly waveguides. The DRA array will be self-sustained through the novel design of a supporting structure to resolve the misalignment issues encountered with placing the DRA above the PRGW structure. In this project, the research team will design, fabricate, and test an array of wideband circularly polarized DRA excited by PRGW technique for millimetre-wave Applications. The expected gain of such design will be around 12-17 dB (based on the array size) with side-lob level better than -10 dB. Circular polarization and impedance bandwidths of around 15-20% are expected as well. The DRA array size is not to exceed 50 x 50 mm2 (based on the array size) on a commercial low loss substrate. The design will be tested and measured at KFUPM as well as Concordia University in Montreal, Canada. The estimated period of the project is 18 months with a proposed budget of 155,600 SAR. This project will allow for the scientific collaboration between KFUPM, Saudi Arabia and Concordia University, Montreal, Canada.