Abstract—This paper represents the design and comparisonof Rectangular, Cylindrical and Triangular Dielectric ResonatorAntenna.
Three shapes of Dielectric Resonator Antenna (DRA)were designed for Single and Dual Band operation with similarfeeding technique i.e. Slot Aperture for C and X-Band frequencyoperations. C and X Band are Microwave Band lies betweenfrequency range 4 to 8 GHz and 8 to 12 GHz.
Antennaconstraints such as dimensions and frequencies are determinedusing mathematical formulas. The three shapes of DRA issimulated by electromagnetic simulator CST Microwave Studio.The Bandwidth, Gain and Directivity of three shapes of DRAare evaluated and it is finally observed that for Single Bandthe Triangular DRA has much wider bandwidth and have highvalue of Directivity and Gain than Rectangular and CylindricalDRA and for Dual Band the Triangular has wider Bandwidththan Rectangular and Cylindrical DRA while Rectangular DRAhas high value of Gain and Directivity than Cylindrical andTriangular DRA at same Resonant frequency. The results of thepresent work may provide design guidelines for the developmentof efficient DRA at C and X Band frequency operations.Index Terms—Bandwidth, Cylindrical Dielectric ResonatorAntenna (CDRA), Dielectric Resonator Antenna (DRA), Directivity,Gain, Rectangular Dielectric Resonator Antenna (RDRA),Triangular Dielectric Resonator Antenna (TDRA).I.
INTRODUCTIONIn 1939, R. D. Richtmyer showed that un-metallized dielectricobjects could function similar to metallic cavities, whichhe called dielectric resonators 1.
Dielectric resonators havereceived great interest in recent years for their potential applicationsin microwave and millimeter wave communicationsystems. They have been widely used as a tuning componentin shielded microwave circuits such as filters7, oscillators,and cavity resonators8.With an appropriate feed arrangement,they can also be used as antennas, and is known asDielectric Resonator Antenna. Since the inception of DielectricResonator Antenna (DRA) by Long et al.
1 in 1983, ithas received increased attention and consideration across theglobe. It was best alternatives of MPAs; however it has notbeen fully explored18 upto now in terms of its applicationsin most of the fields such as its use in satellite technology andat industry level etc. 13. For many years the community ofantenna has been greatly involved in the analysis and researchof Dielectric Resonator Antenna. Many new features need tobe explored to meet the requirements of the miniaturization ofthe portable devices14 and other devices for communicationin all bands used for communication14. The MicrostripPatch Antenna have much contribution in modern SatelliteCommunication as compared to the conventional Antennas7-9 but Microstrip Patch Antenna at C and X-band applicationsuch as Radar and satellite Communication offer high metalliclosses due to the presence of surface waves.
So, the DRAovercome the problem of high metallic losses because it madeof high permittivity dielectric material having less conductorlosses8. Advantages of using DRA over another conductingsurface antenna are such that it prevents the conductorloss12 and surface wave loses at higher frequencies 12-13.The DRA has most attractive features like, small size2-21-22,light weight23, design flexibility, low loss and ease ofexcitation23-24. So for many years, DRAs have been investigatedbecause it has most attractive features4-5.As DRAis made of high permittivity material having less conductorloss33.
The radiation efficiency of DRA is high26. DRAprovides flexibility in term of its geometry. This has madeeasy for the designers to select such type of DRA geometrywhich is suitable for the desired results. We can excite variousmodes inside radiating element of DRA, producing variousradiation pattern for different applications and these variousmodes depends on feeding mechanism as well as the shape ofResonator24-25.As compared with micro strip antenna, theDRA has wider impedance bandwidth and better efficiency andsmall size13.
There are various shapes of the DRA, whichhave been studied like Rectangular 13-14, Cylindrical 15,conical 16 and many more by many researchers.In this paper, the Bandwidth, Directivity and Gain of Single-Band and Dual Band Rectangular, Cylindrical and TriangularDRA are directly compared for C and X-Band applications.For this purpose, Single and Dual Band Rectangular, Cylindricaland Triangular DRA are designed for operation at 6, 7,8, 9, 10 and 11 GHz and Dual Band Antenna are designedfor operation at 6-7, 8-9 and 10-11 GHz with the constraintsthat all antennas possess similar feeding mechanism in CSTMicrowave Studio. The Bandwidth, Directivity and Gain ofthe three shapes of the DRA for Single and Dual Band aremeasured.The result for Single Band shows that not only theimpedance bandwidth of the Triangular DRA is much widerthan Rectangular and Cylindrical DRA but also the Gainand Directivity of the Triangular DRA is noticeably higherthan Rectangular and Cylindrical DRA. And, results for DualBand shows that Impedance bandwidth of the Triangular DRAis much wider than Rectangular and Cylindrical DRA andGain and Directivity of the Rectangular DRA is higher than