Compact omnidirectional circularly polarized dielectric resonator antenna

In this paper, a slot coupled wideband circularly polarized cylindrical ring dielectric resonator antenna (DRA) has been presented. Circular polarization in DRA is generated using slot coupling excited with microstrip feed. Proposed design antenna shows −10 dB input impedance bandwidth of 13.15% and in broadside direction 3-dB axial ratio bandwidth of 10.00%. In addition, proposed antenna shows HEM 12δ mode, stable gain, radiation efficiency and offers right hand circular polarization.

A wideband circularly polarized (CP) dielectric resonator antenna (DRA) with a small aperture feed is proposed. The antenna is made up of two rectangular dielectric layers with the same permittivity that are joined together with an angle a to the bottom layer. An aperture coupled feed is used to excite the antenna through a rectangular slot in the ground plane. The DRA's rotational and layered configuration generates broadside CP radiating modes, and the results show that the axial ratio (AR) bandwidth has been significantly increased. The proposed antenna achieves 48.28% impedance bandwidth and 18.25% AR bandwidth. The average gain within the AR bandwidth is 5.8 dBic with very little disparity. In addition, the proposed dielectric resonator antenna has a low-profile structure. A CP bandwidth-enhancing approach for the DRA is demonstrated in this paper. The antenna can be used for 5G Wi-Fi and satellite communication systems, among many other applications.

In this letter, a wideband compact circularly polarized (CP) dielectric resonator antenna (DRA) is proposed. This antenna consists of two rectangular dielectric layers that are stacked with a rotation angle φ relative to its adjacent bottom layer. The antenna is excited by an aperture coupled through a slot cutting on the ground plane. The rotated-stair configuration of DRA contributes dual broadside CP radiating modes and results in a noticeable enhancement in the axial ratio (AR) bandwidth. The proposed antenna achieves 31% impedance bandwidth and 18.2% AR bandwidth. The average gain within the AR bandwidth is 4.5 dBi with less than 0.5-dB variation. Moreover, the proposed dielectric resonator antenna has a low-profile structure. This work demonstrates a CP bandwidth broadening technique for the DRA. The potential applications of the antenna are 5G Wi-Fi and satellite communication systems.

An improved mutual coupling compensation in circularly polarized (CP) multi-input multi-output (MIMO) dielectric resonator antenna (DRA) is presented in this paper. Using trimming approach, the mutual coupling (MC) between closely spaced DRA units at 0.3λ has been significantly reduced while axial ratio performance has been maintained. Mutual coupling reduction is obtained by trimming the DRA to ensure low mutual coupling below −20dB. The exclusive features of the proposed MIMO DRA include wide impedance matching bandwidth (BW), triple band circular polarization, and suppressed MC between the radiating elements. The impedance bandwidth matches perfectly with a triple band's 3 dB axial ratio (AR). It is designed with characteristic mode analysis with good agreement of the measurement that has been obtained. Using the probe feed method, the DRA and patch strip are coupled together to allow bandwidth widening of the pro-posed DRA. An impedance bandwidth of 34% at a lower frequency to around 2% at a higher frequency was achieved in all resonance frequencies. Thus, we refer to our newly designed DRA as a proposed method for effectively reducing the mutual coupling between DRAs. Additionally, the 3 dB AR bandwidth matched at 3.3 GHz, 4.6 GHz, and 6.3 GHz with a percentage of 11.66%, 3.04%, and 2.22% obtained at the three different frequencies. Note that the proposed DRA exhibits low mutual coupling (below −20 dB) at the targeted frequencies, which is suitable for better signal reception for MIMO applications. By computing, the metrics envelop correlation coefficient, diversity gain, channel capacity loss, and total active reflection coefficient, the MIMO performance of the proposed antenna is verified. The experiments show a close result between simulated and computed validation of the proposed DRA.

A new omnidirectional circularly polarized (CP) cylindrical dielectric resonator (DR) antenna (DRA) is excited by four open-ended logarithmic spiral slots in the ground plane. Radiated E θ and E φ components are obtained from the TM 01δ mode of the DR and the slotted ground plane, respectively. Omnidirectional CP fields can be obtained when E θ and E φ are equal in magnitude but different in phase by 90°. This CP technique does not require any special shape or treatment of DR, greatly facilitating the design. To demonstrate the idea, a prototype using a glass DR was fabricated. It is a dual-function DRA that also serves as the cover of light sources. The prototype has a measured bandwidth of ~6.2%, covering the entire 2.4-GHz WLAN band.

A low-profile cylindrical dielectric resonator antenna (CDRA) with enhanced impedance bandwidth is proposed via sharing a single triple-mode dielectric resonator. Initially, the resonant frequencies of TM 01δ and TM 02δ modes of a conventional CDRA are maintained far away from each other under central probe feed. Next, a circular disk with an annular ring is loaded around the conventional CDRA, aiming to excite an additional mode between these dual modes. The electric fields demonstrate that the previous TM 02δ mode is transformed into the TM 03δ mode for the modified CDRA, and an additional TM 02δ mode is successfully excited between the TM 01δ and TM 03δ modes. As a result, the resonant frequencies of these three radiative modes are reallocated in proximity to each other, thus achieving the desired bandwidth enhancement. In addition, considering the small input impedance of the CDRA, a microstrip feeding line is introduced underneath the central probe for good impedance matching. With these arrangements, the resultant antenna can generate an extended bandwidth under simultaneous radiation of TM 01δ , TM 02δ , and TM 03δ modes. Finally, the proposed CDRA is designed, fabricated, and measured to validate the predicted performance. The simulated and measured results show that the impedance bandwidth (|S 11 | < −10 dB of the antenna is dramatically extended from 8% to about 62% (2.83∼5.36 GHz), while keeping a stable conical radiation pattern. In particular, a low profile property of about 0.15 free space wavelength is achieved as well.

Communication of present era involves Wi-Fi, Wimax and WLAN. Proposed antenna is designed keeping in mind for these particular requirements. Narrow beam may impart large amount of gain for one particular communication requirements. This paper investigates cylindrical dielectric resonator antenna with introducing band gap structure on the circular patch of DRA for imparting high gain. The application of this antenna can had in the field of WLAN. In this paper characteristics of cylindrical Dielectric Resonator Antenna (DRA) using BaZrO3 (er=27) material, are studied. The DRA antenna is designed by using HFSS software which employs the FDTD method for solution. The characteristics of these antennas are investigated with both co-axial feeding and used for exciting the DRA. The experiment is performed on cylindrical DRA shape fed by coaxial and BaZrO3 material of dielectric constant 27.

The eigenmode expansion method is used to evaluate the resonant frequency of a probe fed cylindrical dielectric resonator (DR) antenna, which radiates above an infinite conducting ground plane. A parallel grounded conducting plane is added above the DR, thus allowing the use of cylindrical harmonic field expansions in the regions between the two parallel ground planes. The eigenmode expansion coefficients are found by enforcing the boundary conditions at conducting surfaces and regional interfaces. Then, from the induced currents on the probe surface, the input impedance and the resonant frequency of the DR antenna are evaluated. The results are compared with those of a previous configuration which has no upper ground plane. It is found that the deviation of the calculated resonant frequency is less than 2% for epsilon εr>9.

In this paper, two identical Cylindrical Dielectric Resonator Antennas (CDRA) are stacked together to achieve Circular Polarization (CP). Ultra wideband impedance bandwidth and wide axial ratio bandwidth is achieved by three factors: stacking of similar DRs, stepped conformal microstrip feed line which will generate orthogonal modes and new partial ground plane with circular rings. Measurement results show that the proposed stacked Cylindrical CPDRA achieves an Impedance Bandwidth (IBW) of (S11 < −10 dB) of 72.48% (3.65–7.8 GHz) and Axial Ratio Bandwidth (ARBW) (AR <3 dB) of 44.12% (4.38–6.86 GHz), respectively. In addition, the proposed antenna shows dominant Left Hand CP with gain ranges from 1.4 to 6.5 dBic with maximum radiation efficiency of 93.3%. The advantages and novel points of proposed research work is as follows: (i) The novel configuration of stacking CDRA's along with stepped microstrip feed enhances ARBW, (ii) New proposed partial ground plane with two circular rings provides enhancement in IBW, (iii) Simple design and small height of DRs produces enhanced IBW, ARBW, Gain and Efficiency. Furthermore, by changing the position of circular rings on ground plane, the proposed antenna provides dominant LHCP to RHCP conversion and achieves polarization reconfigurability. The proposed antenna configuration covers the frequency range of applications of C-band and military satellite communication.

This paper describes a dual-band/tri-band switchable dielectric resonator antenna (DRA). The low-profile DRA comprises two cylindrical dielectric layers with same diameters but different permittivities and heights - one with higher permittivity (9.8) and another with low-permittivity (3.38), aperture-coupled fed through a triangular slot. The cylindrical DRA is activated in two separate hybrid modes. A rectangular slot with PIN diode is added to the triangular slot to transition from dual band to tri-band. In PIN diode ON mode, the DRA operates in dual-band mode with 41.78% impedance bandwidth at 5 GHz and 16.45% at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{7 ~ G H z}$</tex>. In OFF mode, DRA operates in tri-band at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3.8 \text{GHz}, 5.9 \text{GHz}$</tex>, and 7 GHz, with impedance bandwidths of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$8.04 \%, 17.08 {\%}$</tex>, and 17.19%. The DRA has a gain of 6.28 dBi at 5 GHz with 81% efficiency and 9.8 dBi at 7.1 GHz with 76% efficiency in PIN diode ON state. In OFF state, DRA achieves gains of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$5.8,6.83$</tex>, and 9.02 dBi at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3.8,5.9$</tex>, and 7.1 GHz bands with 75% efficiency. The frequency-reconfigurable DRA has a low profile with total height of 5.6 mm.

In this article, the design and analysis of a double cylindrical dielectric resonator antenna (CDRA) of compact size 40 × 40 mm2 with extended wideband characteristics for C- and X-band applications is presented. A couple of CDRA is placed over the two adjoin rectangular slots which are excited by a modified microstrip feed line of 50 Ω. The proposed double CDRA resonates between frequency band 4.75 and14.43 GHz with 100.93% (9.68 GHz) impedance bandwidth. Two adjoin rectangularslots with a modified microstrip feed line generate two orthogonal degenerated hybrid modes (HEMx 11δ and HEMy 11δ), which are liable for the creation of circular polarization characteristics between the frequency band 6.62 and 8.5 GHz with 24.86% (1.88 GHz) 3-dB axial ratio bandwidth. The stable peak gain of 6.27 dB at frequency 12.62 GHz, whereas the gain of 3.31–6.27 dB and radiation efficiency of more than 86% in the entire operating band is obtained.

The dielectric resonator antenna (DRA) is quite useful for high frequency applications where ohmic losses become a serious problem for conventional metallic antennas. In addition, they offer higher bandwidths than microstrip patch antennas used in the same frequency range. There are many techniques for increasing the bandwidth of DRAs and many of them increase the complexity of the structure. The paper is concerned with the excitation of two modes with similar radiation characteristics in the same DRA. By adjusting the ratio of the diameter to the height, the modes can be made to resonate close to each other and the bandwidth is thereby increased. The characteristics of the cylindrical DRA and the rectangular DRA are compared. The results show that, by exciting two simultaneous modes, the bandwidth of a DRA can be increased without extensively modifying the geometry.

This letter presents a circularly polarized cylindrical dielectric resonator antenna (DRA) with wide band characteristics. The circular polarization (CP) is actualized by placing a set of symmetric tapered sheets on either side of the feed line, which is quite first time in DRA. The measured results shows 4.0% axial‐ratio (AR) bandwidth for AR &lt; 3 dB, while operating overS11 &lt; −10 dB bandwidth of 16.77% (7.1–8.4) GHz with a peak gain of 5.92 dBi. This proposed low profile compact DRA can be a favorable candidate for X‐band applications.

This paper proposes a dual-band circularly polarized (CP) rectangular dielectric resonator antenna (DRA) for 5G millimeter wave wireless communications. The proposed DRA consists of a novel modified cross-flower exciting (MCF) slot and a rectangular ceramic dielectric resonator (DR). With the help of the compact MCF feeding slot, the fundamental modes TEδ11x/TE1δ1y and higher-order modes TEδ13x/TE1δ3y of the DR can be excited to achieve CP dual-band characteristics. In addition, the MCF slot works as a radiator at 26 GHz and 39 GHz to enhance the DRA bandwidth. More importantly, these two operational bandwidths can be controlled independently at the lower and upper bands. The proposed DRA is designed, fabricated and measured. The measured results show that the proposed dual-band CP DRA achieves 3 dB axial-ratio (AR) bandwidths of 19.8% and 7.8% with peak gains of 5.62 dBic and 6.74 dBic for the lower and upper bands.

This paper investigates a 3-D-printed wideband circularly polarized (CP) dielectric lens antenna (DLA). The DLA consists of a modified extended hemispherical dielectric lens and an integrated cylindrical dielectric resonator antenna acting as a feed. To generate CP radiation, a set of inclined air grooves are inserted into the lens top. To verify the idea, a CP DLA operating at X-band is designed. Its simulated 10-dB impedance bandwidth and 3-dB axial ratio (AR) bandwidth are given by 17.2% (9.57–11.37 GHz) and 14.8% (9.60-11.14 GHz), respectively, with the overlapped bandwidth of 14.8% (9.60-11.14 GHz). Also, the proposed CP DLA has a high simulated peak gain of 12.9 dBic.