Dielectricresonator antennas (DRAs) were first discovered in 1983 by Long et. al., and since then they have been widely studied . There have been several works reported in literature to improve various parameters (impedance bandwidth, axial ratio bandwidth, gain etc.) of DRAs [2-20]. Their inherent features of high radiation efficiency & ease of excitation, compactness, and ability to obtain radiation patterns using different excitation modes offer much to an antenna application . Furthermore, the shape of a DRA can be custom, resulting in favorable operating modes or polarizations. Also, the DRAs supporting circular polarizations have been studied and can be found in the literature. Traditionally, circular polarization is achieved using quadrature couplers and elaborate feed systems which can also be done with DRAs as well [3, 4].
DielectricResonator Antenna: A dielectricresonator antenna has a dielectric layer and a conducting layer formed on a main surface of the dielectric layer. An electrical contact is formed on the main surface for connecting the dielectric layer to a transmission line for transferring a signal between the dielectric layer and the transmission line. The electrical contact is insulated from the conducting layer. A conducting strip is connected to the electrical contact and is on a side surface of the dielectric layer. The side surface is not on the same plane of the main surface. Rather, the side surface is perpendicular to the main surface of the dielectric layer. A dielectricresonator antenna (DRA) is a radio antenna mostly used at microwave frequencies and higher, that consists of a block of ceramic material of various shapes, the dielectricresonator, mounted on a metal surface, a ground plane. Radio waves are introduced into the inside of the resonator material from the transmitter circuit and bounce back and forth between the resonator
In this paper, reconfigurability is added to dielectricresonator antennas, and two types of reconfigurable dielectricresonator antennas are presented. The first is an ultra wideband DRA with a reconfigurable band rejection or notch to help limit interference to different narrowband services operating inside the 3.2–5.1 GHz frequency range. The second is a DRA with reconfigurable resonance frequency suitable for different microwave applications and WiMAX applications. The reconfigurability of the notch and the resonance is achieved by rotation the DielectricResonator (DR) placed on the patch of the antenna, using a DC stepper motor connected to the DR. The characteristics of the designed antennas are investigated via HFSS and experimentally verified.
Microstrip patch  has become a popular resonator for designing the planar reﬂectarray because it is planar and simple in structure. A patch resonator with variable size or length is found to be able to introduce phase shift for reﬂectarray. Nevertheless, conductive and surface wave losses of the patch can be a concern at millimeter wave ranges . It was ﬁrst shown by Long et al.  that the dielectricresonator (DR) can be made an eﬃcient antenna. Since then, the dielectricresonator antenna (DRA) has been extensively explored for various applications because of its advantages such as low loss, wide bandwidth, compact size, and light weight [4, 5]. The use of DR can scale down the antenna size by roughly a factor of 1 / √ ε r , where ε r is the dielectric constant of the DR .
For the new ﬁlter design, design equations for dielectricresonator ﬁlter have been used. The ﬁrst step is choosing an appropriate ﬁlter type compatible with the application and calculating its parameters. In this approach, we have chosen 3rd order Chebyshev ﬁlter with 2% bandwidth.
Dielectricresonator filters have been widely used in mobile communication and space applications due to their relatively small size, high unloaded Q-factor and stable thermal and mechanical performance. Further size reduction can be achieved by exploiting multi-mode degenerate resonances in a dielectricresonator. Since Cohn and Fiedziuszko  first introduced the possibility of realizing high Q-factor filters using the single mode, TE 01 and TM 01 , and dual-mode,
Abstract—A dielectricresonator loaded patch antenna excited by a coaxial cable is proposed in this paper. The results from measurement show a wide impedance bandwidth of 57.1% from 3.75 GHz to 6.75 GHz and a peak gain of 11.5 dB at the center of frequency band with an average gain improvement of 3 dB over the frequency band in comparison with the common dielectricresonator antennas. These results are in good agreement with those obtained by the computer simulations. A simple study of the antenna shows that the aperture size increase is the cause of gain enhancement. A theoretical model based on the simulated gain results of reference antenna and its equivalent aperture is presented for the proposed antenna structure with good agreement with simulation and measurement results. The advantages of the proposed antenna are high gain with broad bandwidth, and low fabrication cost in comparison to other types of high gain DRAs having narrow bandwidths and complex structures.
the dielectricresonator with and without cylindrical air-gap as shown in Figure 3. Figure 3(a) shows how the ﬁeld intersects through both the ports (indicated by red circle) which causes poor isolation at both the bands. When the cylindrical air-gap is introduced, ﬁeld through both the ports is aﬀected at the interface of air-gap, due to the diﬀerence of permittivities, as shown in Figure 3(b). This results in improvement in isolation. Figure 3(c) shows a similar eﬀect in the presence of copper strips at the corner of the radiator.
In this paper a single RDRA excited by a DIL through a slot was numerically investigated by HFSS. The best ground plane width for maximum gain with a broadside radiation pattern was obtained. Results show that 7.7 dB gain at 10 GHz was obtained for 100 mm of ground plane width. Moreover, to increase antenna gain four sidewalls were added and maximum gain of 10.4 dB at 10.4 GHz was obtained which is 2.7 dB higher than the gain in case of structure without them. To reduce back- ward radiation, a reflector was placed at the back of the antenna structure. The results show that adding the re- flector lead to reduce the backward radiation around 10 dB in E-plane, especially. Also, the effects air gap between dielectricresonator and ground plane on the
Abstract—In this paper, a cross-slot-coupled dual-band circularly polarized (CP) hybrid dielectricresonator antenna (DRA) is presented. The design concept is based on using a cross-slot as both a feeding structure of the DRA and an effective radiator. Full wave simulation is used to verify the proposed design concept in this paper. A prototype antenna is designed, fabricated, and measured. Good agreement is obtained between the simulated and measured results.
Hertzian potentials have been used to solve different electromagnetic problems: in the study of the properties of aperture array systems , non-linear waveguides , Green’s functions for multilayered media  and electromagnetic wave interaction with nanodevices . They have also been applied for the determination of TE and TM modes of circular cylindrical cavities using magnetic-type and electric-type Hertzian potentials res- pectively . Figure 1 shows the case of a cylindrical dielectricresonator enclosed by a metal shield, where b is the radius of the outer cylinder, a is the inner resonator radius and d is the height (length of the structure). The configuration can be regarded as a cylindrical waveguide enclosing a central sample of radius a, and terminated by perfectly conducting planes. The general solution for the axial E field in TM modes was discussed in , proposing a general solution for the axial E field for TM modes.
The new reflectarray antenna design consists of dielectricresonator antenna (DRA) unit-cell loaded with alphabet shape slot. Due to the interesting features of DRA such as low loss, broad bandwidth small mutual coupling effect and higher radiation efficiency, thus DRA has become the main subject of the study. Meanwhile, in order to excites the magnetic fields in the DRA , alphabet shape slot is loaded as the main frequency tunable for the DRA. Alphabet shape slot is chosen due to the various geometries.
Abstract—A new design of a circularly-polarized (CP) trapezoidal dielectricresonator antenna (DRA) for wideband wireless application is presented. A single-layered feed is used to excite the trapezoidal shaped dielectricresonator to increase resonant frequency and axial ratio. Besides its structure simplicity, ease of fabrication and low-cost, the proposed antenna features good measured impedance bandwidth, 87.3% at 4.21 GHz to 10.72 GHz frequency bands. Moreover, the antenna also produces 3-dB axial ratio bandwidth of about 710 MHz from 5.17 GHz to 5.88 GHz. The overall size of DRA is 21 mm × 35 mm, which is suitable for mobile devices. Parametric study and measurement results are presented and discussed. Very good agreement is demonstrated between simulated and measured results.
Nanoantenna has high level radiationelements. Optical antenna has unique type of RF strategies to optical or plasmonic realm. Optical DRA has many uncertainties with unique properties with high level approaches Engineered materials or nonmaterials. The function of optical antenna with uses particles like gold particle which has widely used for exploited to achieve every small bit size of context of optical antenna structures ,element play main reasons why these elements well works with THZ Frequency . The dielectricResonator optical antennahas some new design to fabricate new and high level configurable superior conductor which general to improve its potential performance with high level enhancement . The impedance value of Antenna System main integration for nano or micro level communication .The optical antenna has main aim to increase antenna Gain with Low losses. Its design is very usefull because its feeding technique has unique model Expansion which can expansion which can express through low losses of conducting radiation element. The wireless communication Antenna Network design has been interest for researcher from the past few decades due to design and manipulation .The demonstration of optical DRA antenna has special direction as well as control on complex and analytic algorithms. Which is able to control at THZ, GHZ Scale. Although opticalAntenna wavelength propogation providing high and advance level technology for nanoplasmonicdevices.The fabrication process may be describe and explore design that increase the spontaneous emission rate with high level magnitude to improve optical antenna working range depend upon relationship between metalicintraction with nanoscale or THZ Scale .nowdays we are allowing our technology. The dielectricresonator antenna has encouraging develoment for different bands or THZ band have taken on interest .In terms of optical nanoantenna works in to integrate the Antenna with DRA Termed. The permittivity of optical DRA antenna proves the element to be suitable antenna array Application. The antenna gain enhancement depending on increase bandwidth which introduced multiple resonances and minimizing its dimensions. The radiation pattern of any antenna determined by far field radiation or transformation of magnetic current .The optical DRA Frequencies patterns and efficiency of Antenna model show similar radiation patterns .it has lower dielectric material used for made-up Antenna material then achieved Antenna higher order of increasing impedance bandwidth.
Yao-Dong et al.  presented a new single-fed wide dual-band circularly polarized (CP) dielectricresonator antenna (DRA).. The antenna in this article the simulated and measured consequences are shown after completion. In the current age of cellular communication, the research is widely focused on dual polarized DRA because these radiators are insensitive to the orientation and multipath interferences between transmitter and receiver antennas. Numerous researchers have been established various techniques to create CP characteristics in DRA like diversified feeding mechanism and shapes of DRA (semi-eccentric DRA, staked rectangular DRA as well as hybrid cylindrical DRA). Though the beneath rectangular aperture the DRA is excited and its HE 111 and
11. Antar, Y. M. M., D. Cheng, G. Seguin, B. Henry, and M. G. Keller, “Modified waveguide model (MWGM) for rectangular dielectricresonator antenna (DRA),” Microwave and Optical Technology Letters, Vol. 19, No. 2, 158–160, Oct. 5, 1998. 12. Neshati, M. H. and Z. Wu, “The determination of the resonance frequency of the T E Y 111 mode in a rectangular dielectricresonator for antenna application,” 11th International Conference on Antenna and Propagation, 2001, Vol. 1, No. 480, 53–56, 2001. 13. Gurel, C. S. and H. Cosar, “Efficient method for resonant fre-
The dielectricresonator antennas (DRAs) have attracted wide attentions in various applications, as armored filters or oscillators [1,2], They offer several advantages in terms of high radiation efficiency and Q factor. Indeed, when a resonator is placed in a cavity, it presents a high quality factor, which allows the realization of a highly selective filter.
Abstract—Novel compact ultra-wideband (UWB) rectangular stacked dielectricresonator antennas (DRAs) with band-notched characteristics are proposed. The DRAs are designed to cover the FCC band (3.1–10.6 GHz) and have very compact sizes, due to the shorting conductor. Printed dipoles that are placed on one side of the dielectricresonator will resonate and generate band notches within the ultra-wide operating band. Simulations and measurements conﬁrm the validation of the design principle.
Figure 2 presents the variation of mode frequencies with varying height H for a CoP-RDR. As can be seen from Figure 2, there is no variation in Mode-I frequency with changing dielectricresonator height H. The plot points towards an important trait that the antenna yields broadbeam in two planes at frequencies between Mode-I and Mode-II resonances. Therefore, Mode-I frequency provides an initial marker for successfully identifying the broadbeam frequencies. The next step will be to specify the DR height optimum for broadbeam operation. However, using the calculation for single element RDR, the optimum height has already been pointed out to be 18 mm, and the antenna dimensions have a consistent relation with Mode-I frequency wavelength because it does not change with varying DR height. The optimum DR height is found to be 0.32λ g . Once the height is identiﬁed, the exact frequency band at