In this communication, a dual-band antenna is proposed, which integrates a millimeter-wave (MMW) substrate-integrated dielectric resonator antenna (SIDRA) beam-steerable array and long-term evolution (LTE) folded monopole antenna (FMA). The SIDRA, which is a $1\times4$ tightly arranged DRA array with zero edge-to-edge spacing, is developed in the clearance area of the FMA. Hence, the two antennas not only share the same substrate but also share the same aperture. The performance of FMA will not deteriorate by properly locating the SIDRA array. An antenna prototype was fabricated and measured, and the rationality of the design was verified. The LTE FMA can cover the band of 1.78–2.62 GHz (38.2%) and achieve a peak gain of 3.9 dBi, while the MMW array can cover the band of 26.4–29.8 GHz (12.2%) and achieve a peak gain of 10 dBi. The MMW array can support beam-steering angles of ±45°. The high space utilization of the proposed design strategy makes the dual-band antenna suitable for the fifth-generation (5G) mobile terminal applications.

A Dual-Band Antenna for LTE/mmWave Mobile Terminal Applications

An $H$-plane radiation pattern decoupled patch antennas with zero edge-to-edge spacing is presented in this paper. When the two patches are placed together, a higher-order TM11 mode can be excited, and the mutual coupling between the two patch antennas is high with tilted radiation patterns. Therefore, three pairs of metallic vias are inserted into the interface to obtain a radiation pattern decoupling effect, namely a high isolation and boresight radiations simultaneously. To verify the idea, a prototype with zero edge-to-edge spacing is designed at 2.4-GHz WLAN band. Simulation results show that the proposed patch antennas have an isolation larger than 15 dB, whereas the radiation patterns also show symmetry and retain maximum radiation direction along z-axis.

H-Plane Radiation Pattern Decoupled Patch Antennas with Zero Edge-to-Edge Spacing Using Three-Pair Vias

Wideband self-decoupling of bandwidth-enhanced dielectric patch (DP) filtennas with stable filtering response are proposed in this letter. The TM101 and TE121 modes of the DP are combined to design a wideband antenna while its high-order TM111 mode is used to introduce an intrinsic upper radiation null, leading to a good filtering response. Sequentially, <inline-formula> <tex-math notation="LaTeX">$1\times 2$ </tex-math></inline-formula> DP filtennas have been taken as an example to verify that improving the isolation can keep the filtering performance of the filtenna array basically consistent with the original filtenna element, which is a design concept proposed for the first time in this paper. To maintain almost the same filtering response when the antenna elements are spaced closely, the wideband self-decoupling between the antenna elements is obtained by properly choosing the parameters (i.e. dielectric constants of the DP and substrate), without adding extra decoupling structures. For validation, <inline-formula> <tex-math notation="LaTeX">$1\times 2$ </tex-math></inline-formula> closely-spaced filtennas are fabricated and tested. The measured results denote that the prototype has impedance bandwidth (<inline-formula> <tex-math notation="LaTeX">$\vert S_{11}\vert < -10$ </tex-math></inline-formula> dB) of about 21.2% from 4.47 GHz to 5.53 GHz and in-band isolation is over 20 dB. Benefiting from the self-decoupling scheme, the difference of the in-band gain and stopband suppression between the element and <inline-formula> <tex-math notation="LaTeX">$1\times 2$ </tex-math></inline-formula> DP filtennas is reduced significantly, showing stable filtering response of the filtennas.

https://ieeexplore.ieee.org/ielx7/6287639/6514899/09967994.pdf

Wideband Self-Decoupling Dielectric Patch Filtennas With Stable Filtering Response

A new method for beam widening of rectangular dielectric resonator antenna has been introduced by using anisotropic material inside its prism. It is proved that using this method, the radiation of the upper wall can be increased compared to the side walls of the antenna, which in turn leads to an increase in the beam width of the antenna. The antenna consists of two different dielectric layers that are placed alternately in the horizontal direction. The thickness of each of these substrates is small compared to the wavelength. Therefore, the resulting overall structure behaves like an anisotropic medium. A sample of the antenna is fabricated and measured. A good agreement between the simulated and measured results is attained.

Beam widening of rectangular dielectric resonator antenna using anisotropic materials

Broadband co-polarized antenna using monolithic slotted dielectric patch for full-duplex system

A new decoupling method is proposed in this paper, which simultaneously realizes port and radiation pattern decoupling, namely high isolation and undistorted radiation patterns, respectively. The proposed decoupling method shows its effectiveness in 1 × 2 dielectric resonator (DR) antennas (DRAs) even with zero spacing. Conformal strips are attached on the side wall of the DRs and parallel to the E-plane of the DRAs. Coupled from the resonant DR, the conformal strips can generate induced current, thus forming induced field inside the DR. It can be noted that, inside the two DRs, the DR resonant field and strip induced field are anti-phase and in-phase, respectively. Tuning the conformal strips can change the amplitude ratio and phase difference between the resonant and induced fields, which can be used to cancel the fields inside the DR based on superposition principle. When one DR is excited, the field inside the other DR can be very weak. The DRs can then work at their fundamental TEδ11 modes independently. Therefore, their radiation patterns are not distorted together with a high port isolation. A new indicator, energy storage proportion (ESP), is proposed to evaluate the decoupling effect. It can be found that when the ESP gets close to 1, the radiation patterns will be restored together with a high isolation. To verify the idea, 1 × 2 DRAs are designed, fabricated and measured. Reasonable agreement can be observed between the measured and simulated results for both H- and E-plane decoupled cases. All the measured overlapping impedance bandwidths are larger than 6%, the envelope correlation coefficients are lower than 0.059, and the isolations are higher than 20 dB. It should be highlighted that all the radiation patterns in this paper have been restored, useful for practical applications using multiple-input multiple-output techniques.

Port and Radiation Pattern Decoupling of Dielectric Resonator Antennas

Using dielectric vias, we propose a compact and wideband circularly polarized (CP) dielectric resonator antenna (DRA). The dielectric vias are realized by filling barium strontium titanate nanoparticles with a dielectric constant of 20 into a perforated printed circuit board (PCB) substrate. Owing to the high effectivedielectric constant of the dielectric via-loaded PCB substrate, the electrical size of the DRA is reduced. The arrangement of dielectric and air vias inside the DRA structure allows for redistributing the resonant frequencies of different radiating modes. This design incorporates a third higher-order mode into the passband, resulting in wide impedance and axial ratio (AR) bandwidths. A cross slot is used to excite the CP fields. The standard PCB process is utilized to manufacture the antenna structure. The fabricated prototype has measured impedance and AR bandwidths of 46.9% and 26.7%, respectively. The measured overlapping bandwidth is 25.4%. Our prototype has a compact footprint of 0.61 × 0.61 $\lambda^2_0$ where λ0 is the wavelength in free space at the center frequency. The proposed dielectric vias technique has potential abilities in size reduction and bandwidth enhancement.

Compact Wideband Circularly Polarized Dielectric Resonator Antenna With Dielectric Vias

A decoupled $1\times 2$ cylindrical substrate integrated di-electric resonator antennas (DRAs) is presented using metallic vias and rectangular strips. The two externally tangent cylindrical DRAs are implemented in a printed circuit board (PCB) with two different substrate layers, where the upper and the lower sub-strates are used for antenna structure and feed network, respectively. By inserting vertical metallic vias into the upper substrate and attaching horizontal strips at both sides of the intersection, reduced isolation and distorted radiation pattern caused by mu-tual coupling is corrected, resulting in symmetric radiation pat-terns and maximum radiation along z-axis. To verify the idea, a design working at 24.00-24.25 GHz is designed. It can be found that the isolation between the two ports are higher than 15 dB, the envelope correlation coefficient (ECC) is below 0.002, and the maximum radiation is along z-axis, which makes the antenna suit-able for multiple-input and multiple output systems.

Changwu Tong

Papers

Port and Radiation Pattern Decoupling of Dielectric Resonator Antennas

Compact Wideband Circularly Polarized Dielectric Resonator Antenna With Dielectric Vias

Radiation Pattern Decoupling of Low-Profile Substrate Integrated Dielectric Resonator Antennas