Showing papers on "Patch antenna published in 2021"
TL;DR: It is demonstrated that an MXene patch antenna array with integrated feeding circuits on a conformal surface has comparable performance with that of a copper antenna array at 28 GHz, which is a target frequency in practical 5G applications.
Abstract: Highly integrated, flexible, and ultrathin wireless communication components are in significant demand due to the explosive growth of portable and wearable electronic devices in the fifth-generation (5G) network era, but only conventional metals meet the requirements for emerging radio-frequency (RF) devices so far. Here, it is reported on Ti3 C2 Tx MXene microstrip transmission lines with low-energy attenuation and patch antennas with high-power radiation at frequencies from 5.6 to 16.4 GHz. The radiation efficiency of a 5.5 µm thick MXene patch antenna manufactured by spray-coating from aqueous solution reaches 99% at 16.4 GHz, which is about the same as that of a standard 35 µm thick copper patch antenna at about 15% of its thickness and 7% of the copper weight. MXene outperforms all other materials evaluated for patch antennas to date. Moreover, it is demonstrated that an MXene patch antenna array with integrated feeding circuits on a conformal surface has comparable performance with that of a copper antenna array at 28 GHz, which is a target frequency in practical 5G applications. The versatility of MXene antennas in wide frequency ranges coupled with the flexibility, scalability, and ease of solution processing makes MXene promising for integrated RF components in various flexible electronic devices.
83 citations
TL;DR: In this paper, a dual-polarized broadband microstrip patch antenna for a 5G mmWave antenna module on an FR4 substrate is presented. But the proposed antenna was fabricated using a standard FR4 printed circuit board (PCB) process because of its low cost and ease of mass production.
Abstract: This study presents a dual polarized broadband microstrip patch antenna for a 5G mmWave antenna module on an FR4 substrate. The proposed antenna was fabricated using a standard FR4 printed circuit board (PCB) process because of its low cost and ease of mass production. The electrical properties of the FR4 substrate in the 5G mmWave frequency band were also characterized. An air cavity structure was introduced to mitigate the high loss tangent of the FR4 substrate. Capacitive elements such as proximity L-probe feedings and parasitic patches are used to improve the impedance bandwidth of the patch antenna. For the polarization diversity of the massive multiple-input multiple-output (MIMO) capability, the antenna radiator was designed with a symmetrical structure, and the relative position of the L-probes excites the orthogonal resonant modes to enable dual linear polarization. The operation principle of the proposed antenna was thoroughly analyzed by characteristic mode analysis (CMA). The measured bandwidth of a single antenna was 23.1 % (23 ~ 29 GHz) and the gain value was 5 dBi. The measured cross-polarization suppression ratio of single antenna was 15 ~ 20 dB. The measured gain value of $1\times 4$ antenna array was 10 ~ 11 dBi and the cross-polarization suppression ratio was about 20 dB. The size of the proposed single antenna is $0.41\lambda _{0}\times 0.41\lambda _{0}\times 0.1\lambda _{0}$ , and that of a $1\times 4$ antenna array is $2.78\lambda _{0}\times 0.41\lambda _{0}\times 0.1\lambda _{0}$ . The envelope correlation coefficient (ECC) was calculated and was lower than 0.02 in the 5G mmWave frequency band.
60 citations
TL;DR: The MIMO antenna is characterized by a good envelope correlation coefficient (ECC), low Channel Capacity Loss (CCL), and high diversity gain, which proves that the presented antenna can be seamlessly housed in miniaturized 5G smart devices.
Abstract: This article presents a printed antenna owing the advantages of compact size and simple geometrical configuration for fifth-generation (5G) 28 GHz communication systems. For better performance and miniaturization purposes, both the ground plane and the radiator of the patch antenna are defected with a rectangular slot. The antenna presents a wide operating bandwidth and high radiation efficiency while keeping reasonable gain. Furthermore, two elements Multiple-Input-Multiple-Output (MIMO) configuration of the proposed antenna was designed for MIMO applications. The MIMO antenna is also characterized by a good envelope correlation coefficient (ECC), low Channel Capacity Loss (CCL), and high diversity gain, which proves that the presented antenna can be seamlessly housed in miniaturized 5G smart devices. The proposed work is verified by experiments which are well-matched with predicted results. In comparison with other related works, the presented work is dominant in terms of wide operating bandwidth, high isolation, low ECC, and compact design.
55 citations
TL;DR: In this article, a dual-polarized highly-folded self-grounded Bowtie antenna that is excited through I-shaped slots is proposed for applications in sub-6GHz 5G MIMO antenna systems.
Abstract: In this paper, a novel dual-polarized highly-folded self-grounded Bowtie antenna that is excited through I-shaped slots is proposed for applications in sub-6GHz 5G multiple-input-multiple-output (MIMO) antenna systems. The antenna consists of two pairs of folded radiation petals whose base is embedded in a double layer of FR-4 substrate with a common ground-plane which is sandwiched between the two substrate layers. The ground-plane is defected with two I-shaped slots located under the radiation elements. Each pair of radiation elements are excited through a microstrip line on the top layer with RF signal that is 180° out of phase with respect to each other. The RF signal is coupled to the pair of feedlines on the top layer through the I-shaped slots from the two microstrip feedlines on the underside of the second substrate. The proposed feed mechanism gets rid of the otherwise bulky balun. The Bowtie antenna is a compact solution with dimensions of 32×32×33.8 mm3. Measured results have verified that the antenna operates over a frequency range of 3.1–5 GHz and exhibits an average gain and antenna efficiency in the vertical and horizontal polarizations of 7.5 dBi and 82.6%, respectively.
52 citations
TL;DR: In this paper, a low-profile decoupling structure originated from the phase shift concept for the patch antenna array is proposed, which is composed of a half-wave microstrip line and a shorting pin.
Abstract: In this article, a new low-profile decoupling structure originated from the phase shift concept for the patch antenna array is proposed. To clearly illustrate the operation principle, the phase of the signal transmitted from Patch 1 to Patch 2 has been initially studied and the decoupling condition for two closely spaced patch antennas in H-plane has also been obtained. Afterward, the decoupling element concisely composed of a half-wave microstrip line and a shorting pin is developed. Attributing to the introduction of additional signal path by the new decoupling structure, mutual coupling between two adjacent patches is effectively suppressed. To verify the feasibility of the proposed design scheme, demonstrators of two-element patch antennas with and without decoupling structure are, respectively, implemented and analyzed. Results indicate that compared with the coupled array, the isolation between two patch elements is enhanced from 7 to 18 dB at the center frequency of 3.16 GHz under the edge-to-edge separation of only 0.027 $\lambda _{0}$ . Besides, owing to the single layer layout, the profile of the whole antenna structure is as low as 0.02 $\lambda _{0}$ . Ultimately, the proposed decoupling scheme has been applied to the three-element counterpart, so as to demonstrate and validate its effeteness of isolation enhancement for multielement patch array.
50 citations
TL;DR: The wideband antenna presented in this paper offers omnidirectional stable radiation patterns, good gains, and efficiency with a compact size which make this design an ideal contender for wireless fidelity (WiFi), wireless local area network (WLAN), LTE, and sub-6 GHz 5G communication applications.
Abstract: This paper presents a low-profile multi-slotted patch antenna for long term evolution (LTE) and fifth-generation (5G) communication applications. The studied antenna comprised of a stepped patch and a ground plane. To attain the required operating band, three slots have been inserted within the patch. The insertion of the slots enhances the capacitive effect and helps the prototype antenna to achieve an operating band ranging from 3.15 to 5.55 GHz (S11 ≤−10 dB), covering the N77/N78/N79 for sub-6 GHz 5G wireless communications and LTE bands of 22/42/43/46. The wideband antenna presented in this paper offers omnidirectional stable radiation patterns, good gains, and efficiency with a compact size which make this design an ideal contender for wireless fidelity (WiFi), wireless local area network (WLAN), LTE, and sub-6 GHz 5G communication applications.
43 citations
TL;DR: A four-Port annular-ring patch antenna generating four decoupled waves in 3.3–5.0 GHz with antenna efficiency better than about 84% and envelope correlation coefficients (ECCs) less than 0.05 is presented for fifth-generation multi-input–multi-output (MIMO) access-point applications.
Abstract: A four-Port annular-ring (AR) patch antenna generating four decoupled waves in 3.3–5.0 GHz (41% at 4.15 GHz) with antenna efficiency better than about 84% and envelope correlation coefficients (ECCs) less than 0.05 is presented for fifth-generation multi-input–multi-output (MIMO) access-point applications. The AR patch is placed 10 mm above the ground plane and its four ports are equally spaced by 90° (at $\varphi = 0^{\circ }$ , 90°, 180°, 270°) in the patch. Each Port is surrounded by a ring gap to achieve enhanced impedance matching. Additionally, four gap-coupled shorting (GCS) strips equally spaced by 90° (at $\varphi = 45^{\circ }$ , 135°, 225°, 315°) are added to short-circuit the patch to the ground plane, so that two adjacent ports are separated by one GCS strip. The arrangement makes the four ports capable of generating four decoupled waves with very low ECCs in 3.3–5.0 GHz. An extended design to achieve better isolation between ports is also addressed.
41 citations
TL;DR: It is proposed that multiple parasitic patches are potential for cognitive radio applications where circular patch covers bandwidth of 85% with radiation pattern for Spectrum Utilization and CP with meander lines feeding behaves as communication antenna operating at Wireless Local Area Network 802.11y (3.637 GHz).
Abstract: A micro strip patch antenna with multiple parasitic patches for Cognitive Radio Network applications is presented to enhance the bandwidth. Multiple resonances are used for the design of antenna, with a view to broaden bandwidth. A modified Koch Fractal antenna is imprinted from micro strip radiating patch. A Parasitic Strip line helps to grasp micro hertz communication through antenna. A slotted patch energized by a gap feed was established before with a large angular coverage over a bandwidth of 13.1%. In this paper, it is proposed that multiple parasitic patches are potential for cognitive radio applications where circular patch (CP) covers bandwidth of 85% with radiation pattern for Spectrum Utilization (SU) and CP with meander lines feeding behaves as communication antenna operating at Wireless Local Area Network 802.11y (3.637 GHz). The transceiver in a communication network is powered by Proposed Antenna, to acquire improved energy efficiency of 95.7%. Thus, throughput and SU have been improved, a model of antenna has been fabricated and its radiation patterns, return losses were achieved which shows fine consistency with simulated results.
39 citations
TL;DR: The results denote that the proposed method is easily realized with a very small effect on the radiation performance of antenna elements, making it to be a potential and valuable decoupling and filtering solution for large-scale arrays.
Abstract: Facing the demand for decoupling and filtering for large-scale antenna arrays in modern communication systems, a transmission-line-based scheme is proposed and studied in this article. Different from other decoupling networks published recently featuring narrow decoupling bandwidths and high spurious levels, the proposed approach uses simple T-shaped networks where decoupling and filtering responses are realized simultaneously, leading to high-frequency selectivity and improved decoupling bandwidth. The proposed design is a simple 1-D configuration but powerful for 2-D arrays. Based on the study case of a $4\times {4}$ dual-polarized patch array, theoretical analysis and full-wave simulation are carried out to verify the performance in decoupling and frequency selectivity of this method. A prototype is further fabricated, assembled, and measured to demonstrate the performance of the proposed method in practice. The measured and simulated results are consistent with each other where a low insertion loss of around 0.6 dB is observed. The results denote that the proposed method is easily realized with a very small effect on the radiation performance of antenna elements, making it to be a potential and valuable decoupling and filtering solution for large-scale arrays.
38 citations
TL;DR: In this paper, a low profile and broadband metasurface antenna is proposed for circular polarization radiation, where two characteristic modes with the same resonant frequencies and orthogonal current distributions are chosen as operation modes.
Abstract: A low-profile and broadband metasurface antenna is proposed for circular polarization radiation. The metasurface is an array of subwavelength square patches. The modal behaviors of the proposed metasurface are investigated by using the characteristic mode theory. Two characteristic modes with the same resonant frequencies and orthogonal current distributions are chosen as operation modes. Furthermore, a hybrid feed system consisting of a cross-slot and a microstrip line is employed to excite the two orthogonal modes having a 90° phase difference to obtain circular polarization radiation. Based on these concepts, an antenna with low profile of $0.07{\lambda _0}$ ( ${\lambda _0}$ is the free-space wavelength at an operation frequency of 5.5GHz) is designed. The measurement results show that the proposed antenna has −10 dB impedance bandwidth of 4.8–6.35 GHz and 3 dB axial-ratio bandwidth of 4.85–6 GHz. Moreover, the antenna gain is 6.8–9.7 dBic in the whole axial-ratio bandwidth.
37 citations
TL;DR: Spectrum underlay finite element line feeding technique (SUFELF) is proposed to design MPA's are potential for cognitive radio applications (CRA), which can discover a lot of applications in designs for S band, efficient spectrum utilization in cognitive radio networks (CRN).
Abstract: A micro strip patch antenna (MPA) is fabricated to increase the bandwidth. The communication systems want antennas with high directivity, high signal strength and gain. In this paper, spectrum underlay finite element line feeding technique (SUFELF) is proposed to design MPA's are potential for cognitive radio applications (CRA). The proposed SUFELF is designed and simulated by using HFSS-14, simulation and calculated results of SUFELF for S-band is compared. The proposed SUFELF construction can discover a lot of applications in designs for S band, efficient spectrum utilization in cognitive radio networks (CRN). To improve gain, The MPA with circular patch (CP) was fabricated through SUFELF. This design can carry out a gain of 4.21 dBi, and percentage of impedance bandwidth is 85.2% at 3.546 GHz. A SUFELF model has made-up and calculated, the results have revealed a excellent concurrence by means of the simulations. To obtain efficiency of 95.9% the Proposed Antenna (PA) is powered. We conclude this work with a discussion on the expansion to the coexistence with different patch antennas.
TL;DR: In this article, a metasurface (MS)-based method for broadband radar cross section (RCS) reduction of circularly polarized (CP) patch antennas is proposed in a much broader band than the operational band of the antenna.
Abstract: A novel metasurface (MS)-based method for broadband radar cross section (RCS) reduction of circularly polarized (CP) patch antennas is proposed. The RCS reduction is achieved in a much broader band than the operational band of the antenna. The simple technique is based on MS units on a grounded substrate in a checkerboard-like configuration. The broadband RCS reduction is achieved by combining two different destructive interference principles. In the high-frequency region, for a normal incident wave, the RCS is reduced by the phase cancellation generated by the MSs and the grounded substrate. In the low-frequency region, the RCS is reduced by the polarization conversion property of the MS. In this case, the fields reflected by two MS sections are in counter phase for a normal incident wave. The MS is combined with a CP patch antenna. It concerns a traditional corner-truncated square patch and four sequentially rotated surrounding MS cells. This dedicated MS allows two things: an additional resonant mode is excited resulting in a 3 dB AR bandwidth extension from 4.2% to 15.9% and a broadband RCS reduction of over 6 dB from 4.95 to 15.73 GHz (104.25% bandwidth) for both $x$ - and $y$ -polarized incident waves.
TL;DR: In this article, a wideband differentially fed patch antennas under dual high-order modes for stable high gain are proposed in this communication, where two open slots are loaded to the patch edge to reconstruct the current distribution of TM31 mode, thus substantially increasing the broadside radiation and an additional slot is introduced at the patch center to perturb the TM12 mode and reshape its current to be more in-phase.
Abstract: Wideband differentially fed patch antennas under dual high-order modes for stable high gain are proposed in this communication. The working principle is verified on a differentially fed circular patch antenna operating in TM31 and TM12 modes at first. Two open slots are loaded to the patch’s edge to reconstruct the current distribution of TM31 mode, thus substantially increasing the broadside radiation. An additional slot is introduced at the patch center to perturb the TM12 mode and reshape its current to be more in-phase, by which sidelobe radiation is dramatically reduced. With use of loading of slots and shorting pins, the two modes are allocated in resonant frequencies to make up an enhanced bandwidth of 13.4% and produce high gain up to 13.7 dBi, with the beamwidth and gain level nearly unchanged in band. Then, the proposed method is further developed on a rectangular patch antenna, where three cascaded slots and four shorting pins are loaded to perturb TM21 and TM03 modes, and reshape their current distributions. In a similar way, the broadside radiation of TM21 mode is enhanced and the sidelobe of TM03 mode is suppressed. At last, the antenna obtains a bandwidth of 12.4% and stable realized gain as high as 14.0 dBi.
TL;DR: In this article, a dual slant polarized antenna for millimeter-wave (mmWave) base stations is proposed, which offers the advantages of high cross-polarization discrimination (XPD), good aperture efficiency, simple structure, and low profile.
Abstract: This article presents a novel dual slant polarized antenna for millimeter-wave (mmWave) base stations. Compared with the traditional slant polarized mmWave antennas, the proposed antenna offers the advantages of high cross-polarization discrimination (XPD), good aperture efficiency, simple structure, and low profile. The corner-fed substrate integrated waveguide (SIW) cavity is adopted to improve the port isolation and XPD of this slot-coupled antenna. Four corner-truncated patches connected by a thin cross strip are placed over the SIW cavity to increase the operation bandwidth. Then, a $2\times 8$ antenna array is designed to exemplify the antenna element performance. To improve the impedance matching, a shorted patch is introduced in designing the series feeding network and the power divider. The experimental results show that the 2 dB-down gain bandwidth of the proposed antenna array reaches 6.0% and the port isolation is better than 20 dB. The gain and XPD of the antenna array measure 16.7 dBi and 25 dB at the center frequency, respectively.
TL;DR: In this article, a high-gain substrate-integrated waveguide (SIW) filtering patch antenna with low H-plane cross-polarization (cross-pol) and controllable radiation nulls is proposed.
Abstract: In this communication, a high-gain substrate-integrated waveguide (SIW) filtering patch antenna with low H-plane cross-polarization (cross-pol) and controllable radiation nulls is proposed. The antenna is composed of a radiation patch integrated with three pairs of shorting pins and a single layer SIW cavity with two transverse slots. The shorting pins loaded on the patch can improve the gain and reduce the H-plane cross-pol of the antenna. The long slot on the middle layer can not only split the TE110-mode resonator into two half-mode resonators but also generate magnetic coupling between half-mode resonators and the patch. Another short slot achieves mixed electric and magnetic coupling between the left half-mode resonator and the patch that introducing controllable radiation nulls to improve the selectivity. By adjusting the parameters of the short slot, the positions of two radiation nulls can be easily controlled. Finally, one prototype filtering antenna is fabricated and measured for demonstration. Experimental results show that the proposed SIW filtering antenna achieves a high gain of 9 dBi with only one radiator and has the merit of high-frequency selectivity as well as low H-plane cross-pol of lower than −43 dB.
TL;DR: A novel topology of combining a stacked patch antenna at 2.4/5 GHz bands and a magnetic-electric (ME) dipole antenna at 60-GHz with shared-aperture is developed, featuring the same linear polarization and broadside radiation patterns.
Abstract: Integrated antenna systems that support multiple wireless standards (microwave and millimeter-wave bands) have become a pivotal issue in future wireless networks. The joint implementation of these frequency bands that can provide long-range and short-range radio accesses within a wireless system is desired. However, due to the large frequency difference between different bands, it is hard to realize with limited space. To solve this problem, a novel topology of combining a stacked patch antenna at 2.4/5 GHz bands and a magnetic-electric (ME) dipole antenna at 60-GHz with shared-aperture is developed in this article. Based on the methodology of aperture reuse, a highly-integrated tri-band antenna system with a large frequency ratio and good isolation is reasonably designed, featuring the same linear polarization and broadside radiation patterns. For experimental demonstration, an elaborate prototype is fabricated and tested. The measured -10-dB impedance bandwidths among the three bands can satisfy the criterions of the IEEE 802.11 b/a/ad for wireless local area networks (WLANs, 2.4-2.485 GHz and 5.15-5.85 GHz) and wireless gigabit (WiGig, 57-64 GHz) operations
TL;DR: In this article, a dual-probe filtering antenna with a cascaded triplet (CT) filter and a cascade quadruplet (CQ) filter was designed for verification.
Abstract: In this article, we present a design method of high-selectivity filtering antennas based on a dual-probe feeding structure. The first stage of the filtering circuit consists of two or three coupled resonators which are then coupled to the radiating patch acting as the last resonator of the filter. Cross-coupling is used to obtain transmission zero, and thus the selectivity of the filtering antennas is improved. A cascaded triplet (CT) filtering patch antenna, which produces a radiation zero at the high-frequency edge of the passband, and a cascaded quadruplet (CQ) filtering patch antenna, which produces radiation zeros at both edges of the passband, are designed for verification. The process of designing the filtering patch antenna is given in detail. The designed CT filtering patch antenna has a bandwidth of 1.029–1.17 GHz and a radiation zero at 1.19 GHz. The designed CQ filtering patch antenna has a bandwidth of 1.029–1.17 GHz and two radiation zeros at 1.012 and 1.19 GHz, respectively. The peak gain of the CT filtering patch antenna is 9.35 dBi and that of the CQ filtering patch antenna is 9.16 dBi. A dual-polarized CQ filtering patch antenna is fabricated, showing a good performance in measurement.
01 Feb 2021-Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems
TL;DR: In this article, the design and simulation of RF MEMS switch taken on Microstrip patch antenna loaded with the circular type CSRR is presented, where the two switches moves from upstate to down state arranged on the feeding line provided with the CPW.
Abstract: This Paper Presents the design and simulation of RF MEMS switch taken on Microstrip patch antenna loaded with the circular type CSRR. The Tunability of the patch antenna is achieved when the two switches moves from upstate to down state arranged on the feeding line provided with the CPW. The actuation voltage required to move the switch downwards is 7.6 V. The switch operates at transition time of 0.8 µsec with the capacitance ratio 10. The return loss (S11) of antenna − 28.67 dB is observed at the frequency of 19 GHz when one switch is in on state and at 16 GHz frequency the S11 of − 29.31 dB is achieved by actuating the 2 switches at a time, which gives the reconfigurable property of the antenna. The antenna provides 2 GHz and 5 GHz frequency shift when single and both the switches are in on state. The antenna can be tuned for various applications in the range of 15–30 GHz frequency. The characteristics of switch has been observed by simulating the switch design in FEM tool and results have been compared with theoretical calculations. The tunable characteristics of antenna has been observed and presented by using HFSSV.13 tool.
03 May 2021
TL;DR: A textile-based stretchable microstrip patch antenna with intrinsic strain for e-textiles with seamlessly integrated multifunctional devices and the use of a highly deformable fully meshed textile antenna as a strain sensor capable of measuring joint angles of a human limb is demonstrated.
Abstract: This paper presents a textile-based stretchable microstrip patch antenna with intrinsic strain for e-textiles with seamlessly integrated multifunctional devices. Several microstrip antennas have been developed with the patch alone (stretchable up to 40%) or both the patch and the ground plane (stretchable up to 100%) meshed by using rectangular serpentine units. The changes in the resonant frequency of the meshed antennas, as a result of stretching, have been exploited to demonstrate the intrinsic uniaxial strain sensing. The obtained results indicate that resonant frequency decreases linearly with increasing applied strain, suggesting that the designed antennas can also be used as strain sensors with stretchability up to 100% and a sensitivity of 0.25. The results were validated through full-wave electromagnetic simulations and a two-dimensional digital image correlation (DIC) technique to model the antenna deformations during the tensile tests. In terms of stretchability, the meshed textile patch antenna on a solid ground plane showed more than a 2-fold improvement compared to a meshed gold patch antenna, showing a linear frequency shift. As potential applications, we demonstrate the use of a highly deformable fully meshed textile antenna as a strain sensor capable of measuring joint angles of a human limb. To do that, a microwave readout circuit based on RF to DC rectifier was realized. The rectifier obtained a peak conversion efficiency of 71% at 10 dBm input power overload resistor of 3 kΩ.
University of Rome Tor Vergata1, London Metropolitan University2, Xidian University3, Monterrey Institute of Technology and Higher Education4, Islamic Azad University5, Edinburgh Napier University6, University of Bradford7, Université catholique de Louvain8, University of Aveiro9, Institut national de la recherche scientifique10, Universidad Pública de Navarra11
TL;DR: In this article, a metamaterial-inspired T-matching network is directly imbedded inside the feedline of a microstrip antenna to realize optimum power transfer between the front-end of an RF wireless transceiver and the antenna.
Abstract: In this paper a metamaterial-inspired T-matching network is directly imbedded inside the feedline of a microstrip antenna to realize optimum power transfer between the front-end of an RF wireless transceiver and the antenna. The proposed T-matching network, which is composed of an arrangement of series capacitor, shunt inductor, series capacitor, exhibits left-handed metamaterial characteristics. The matching network is first theoretically modelled to gain insight of its limitations. It was then implemented directly in the 50- $\Omega $ feedline to a standard circular patch antenna, which is an unconventional methodology. The antenna’s performance was verified through measurements. With the proposed technique there is 2.7 dBi improvement in the antenna’s radiation gain and 12% increase in the efficiency at the center frequency, and this is achieved over a significantly wider frequency range by a factor of approximately twenty. Moreover, there is good correlation between the theoretical model, method of moments simulation, and the measurement results.
01 Jan 2021
TL;DR: In this article, a multiband microstrip patch antenna with three slits operating in the LoRaWAN (Long Range Wide Area Network) and the cellular (GSM-1800 and UMTS) communication frequency bands is presented.
Abstract: Radio frequency energy harvesting has attracted considerable interest as a technique of enabling self-powered wireless networks. This technique faces several challenges, such as the receiving and the rectifying modules of a rectenna system. Multiband antennas provide several comparative advantages against the goal of maximizing the amount of energy harvesting. In this work, we present a multiband microstrip patch antenna with three slits operating in the LoRaWAN (Long Range Wide Area Network) and the cellular (GSM-1800 and UMTS) communication frequency bands. A feasible solution of the antenna is obtained by the application of a recently introduced nature-inspired optimization technique, namely the Coyote Optimization Algorithm. The proposed antenna operates satisfactorily in the LoRaWAN (Long Range Wide Area Network) and the cellular (GSM-1800 and UMTS) communication frequency bands. Measured results of the proposed antenna exhibit an acceptable performance (multiband frequency operation, maximum gain of 3.94 dBi, broadside operation) and demonstrate features of operation, which make it a strong candidate for various RF energy harvesting applications.
TL;DR: In this paper, an S-shaped metasurface (MTS)-based wideband circularly polarized (CP) patch antenna was proposed for C-band uplink frequency spectrum.
Abstract: This research proposed an S-shaped metasurface (MTS)-based wideband circularly polarized (CP) patch antenna for C-band uplink frequency spectrum. The proposed MTS-based CP patch antenna was of low profile and fabricated on three substrate layers: upper, middle, and lower. The upper substrate contained $4\times 4$ periodic S-shaped MTS elements, the middle substrate functioned as ground plane with a rectangular-shaped slot at the center, and the lower substrate contained a coplanar waveguide with microstrip and ground. The S-shaped MTS elements converted linearly polarized (LP) into CP wave. Simulations were performed, and an antenna prototype was fabricated and experiments carried out. The measured impedance bandwidth and axial ratio bandwidth (ARBW) at the center frequency of 5.9 GHz were 43.22% (4.05 – 6.6 GHz) and 22% (5.3 – 6.6 GHz), respectively, rendering the proposed antenna suitable for satellite communication applications. The proposed antenna achieved the maximum gain of 6.16 dBic at 5.6 GHz. The novelty of this research lies in the use of S-shaped MTS elements to efficiently convert LP into CP wave and achieve wider ARBW for the C-band uplink spectrum.
TL;DR: In this article, a low-profile high-directivity circularly polarized patch antenna is proposed, where two orthogonal slots are etched out in the middle of a square patch.
Abstract: A low-profile high-directivity circularly polarized patch antenna is proposed in this article. Two orthogonal slots are etched out in the middle of a square patch. As a result, radiation patterns of original TM12/21 modes are reshaped to the desired ones that are similar to those of TM10/01 modes, leading to significant enhancement of broadside radiation. To accommodate the modified current distributions of the two operating modes, a pair of perturbed stubs is proposed and then loaded on the slot-loaded patch, which leads to the quadrature-phase difference. In order to suppress unwanted modes that tilt the radiation pattern away from broadside direction, differential-fed configuration instead of single-fed one is adopted to excite modified TM12/21 modes. Characteristic modes theory (CMT) is used to analyze the input impedance of differential-fed patch antenna and determine the two feeding positions. Next, the proposed antenna is compared with three conventional ones, which reveals its superiority in the highest directivity. Besides, it is also discussed how to determine the size of the finite ground plane. We find that the size of $1.5\lambda _{0} \times 1.5\lambda _{0} $ can increase directivity slightly and effectively prevent radiation pattern from tilting tendency. Finally, a prototype antenna is fabricated and measured for validation.
TL;DR: In this article, the integration of an interdigitated capacitor (IDC), acting as a sensor, into an aperture coupled patch (ACP) antenna, such that weak coupling is established between the IDC and the rectangular patch resonator, is described.
Abstract: Wireless sensor elements integrated with miniaturized antennas are useful in various applications such as wearable chemical and environmental sensors and Internet-of-Things (IoT) sensor nodes. A major problem in antenna operation is detuning of the antenna bandwidth due to loading by the sensor element. In this article, we report on the integration of an interdigitated capacitor (IDC), acting as a sensor, into an aperture coupled patch (ACP) antenna, such that weak coupling is established between the IDC and the rectangular patch resonator. Because of low mutual coupling, during the sensing process the antenna is not detuned out of its operational bandwidth and its performance is not compromised by the presence of the sensor and vice versa. A sensing material (barium titanate film) is deposited on the IDC located at the edge of the microstrip line used to slot-feed the ACP antenna. A change in the material permittivity is transduced into a variation of resonant frequency of the antenna. We describe the design and fabrication of the IDC sensor-integrated ACP antenna and demonstrate the measured sensing performance at different temperatures and relative humidity concentrations.
TL;DR: In this article, the effects of parasitic elements on the performance of MIMO patch antennas were investigated and two antennas coupled in H-plane and E-plane were designed and measured to demonstrate the proposed concept.
Abstract: This paper investigates the effects of parasitic elements on the performance of MIMO patch antenna. Multiple square parasitic elements are added in close proximity to each of the rectangular patch elements. These parasitic elements affect the electromagnetic field distribution and consequently reduce the mutual coupling. In addition, wider bandwidth is also achieved. Two MIMO antennas coupled in H-plane and E-plane are designed and measured to demonstrate the proposed concept. The measured results show that both designs have a wide impedance bandwidth of 14% with isolation of more than 20 dB across the whole band (with a small antenna profile of $0.05\lambda _{0}$ ). For 40-dB isolation, the H-coupled and E-coupled design achieve a bandwidth of 2.7% and 1.5%, respectively. Compared to other methods, the proposed method has much simpler structure, wider bandwidth and comparable improvement in isolation, with the tradeoff in larger antenna element size.
TL;DR: In this paper, a tunable terahertz (THz) two-port graphene patch antenna having isolation between the ports of the order of 40dB over the whole range of tunability is presented.
TL;DR: In this article, a single-fed wideband circularly polarized split patch antenna with two suspended metal rods is proposed, which has two semi-circular patches with a suspended metal rod loaded on each patch.
Abstract: A novel single-fed wideband circularly polarized (CP) split patch antenna with two suspended metal rods is proposed in this letter. The proposed antenna has two semi-circular patches with a suspended metal rod loaded on each patch. The antenna is fed by a coupling slot and a hammer-headed microstrip line on the opposite side. Two inclined semicircular patches are combined with slot to form a CP radiation at low-frequencies band; furthermore, two suspended metal columns form a loop-type antenna at high-frequency band, which are combined with the slot forming another CP resonance point. The combination of these two CP resonance points broadens the CP bandwidth which is indicated by the AR curve. The proposed antenna has a simulated 3 dB AR bandwidth of 22.58% (4.87–6.11 GHz) and a wide −10 dB impedance bandwidth of 48.75% (3.8–6.25 GHz). The overall electrical size of the antenna including the ground is 0.46 × 0.46 × 0.154 λ03 (with λ0 being the free-space wavelength at 5 GHz). The measured peak gain of the antenna is greater than 8 dBic from 5 to 6 GHz. A 2 × 2 antenna array based on the proposed antenna element is also implemented and experimentally verified. The 2 × 2 array has a 3 dB AR bandwidth of 49.7% (4.02–6.68 GHz). This proposed antenna and its array exhibit a very novel structure and an interesting working principle while demonstrating excellent CP radiation performance. They could be applied in various 5G or other communication systems, which require CP radiation.
TL;DR: In this article, an innovative frequency reconfigurable metamaterial-based microstrip patch antenna was proposed for multiple bands by using a PIN diode as a switch, which achieved frequency tunability for a range of 3 GHz to 9 GHz.
Abstract: The manuscript represents an innovative frequency reconfigurable metamaterial-based microstrip patch antenna. The proposed structure provides frequency tunability for multiple bands by using a PIN diode as a switch. The performance of the proposed antenna structure is simulated, fabricate, and compared for copper and liquid (water-sea) based split-ring resonator (SRR). The tooth is added to the outer of the split-ring resonator for gain enhancement and better frequency tunability. Frequency tunability is achieved by connecting the patch antenna with a PIN diode that reduces the size of the antenna. Five switching modes (all switch off, one switch on, two switches on, three switch on and all switch off) of the proposed antenna structure is presented and their reflectance response (s11), the number of bands, bandwidth, directivity, and total gain is compared for copper and liquid (water-sea) structure with and without a tooth. Results of Fabricated structure and simulated also compared. Frequency tunability is observed for a range of 3 GHz to 9 GHz. The proposed antenna is useful for a weather forecast, satellite communication, and raw satellite feed and many more.
TL;DR: In this article, a characteristic mode rotation (CMR) method has been proposed to design a compact metasurface antenna with a low radar cross section (RCS) in a wideband.
Abstract: In this paper, a characteristic mode rotation (CMR) method has been proposed to design a compact metasurface antenna with a low radar cross section (RCS) in a wideband. In the proposed CMR method, the incident wave dependent complex characteristic currents corresponding to the dominant characteristic modes solved by the characteristic mode method (CMM) are calculated. With the direction of the superposition of the complex characteristic currents orthogonal to that of the incident electric field in the CMR method, the metasurface subarray with wideband polarization conversion characteristic is designed. By arranging the metasurface subarray in a rotation way, a metasurface array with a compact size of 1.28λ0×1.28λ0 is designed for wideband RCS reduction. A miniature circle patch antenna is integrated with the metasurface array to achieve not only good radiation performance but also low observability for the in-band and the out-of-band of the antenna. Simulated and measured results demonstrate that the proposed miniature metasurface antenna designed by the CMR method has a good broadside radiation pattern, a maximal gain of 10.75 dB, and a -10 dB RCS reduction characteristic in the wide band of 6∼20.7 GHz with a fractional band of 110%.
TL;DR: In this article, a direct LIG printed microstrip patch antenna operating at the 5.8 GHz unlicensed band is presented based on simulations, the proposed design exhibited the desired unidirectional radiation characteristics with a measured gain of 1.82 dBi at the resonant frequency.
Abstract: Leveraging laser-induced graphene (LIG) in various flexible polymer electronics applications is becoming tremendously popular. LIG is porous multilayer graphene generated by a single-step process using infrared CO2 laser onto the carbon-based polymers. In this article, a direct LIG printed microstrip patch antenna operating at the 5.8-GHz unlicensed band is presented. Based on simulations, the proposed design exhibited the desired unidirectional radiation characteristics with a measured gain of 1.82 dBi at the resonant frequency. The LIG-based rectangular patch was printed using the CO2 laser by selective reduction of polyimide (PI) sheet. The chemical properties of LIG were examined using various structural and morphological characterization techniques, which confirmed the formation of multilayer graphene. The sensitivity of the patch antenna was analyzed for measuring strain and its effect on LIG. By harnessing LIG on flexible material such as PI sheet, the antenna exhibited a threshold increase in sensitivity. The proposed sensor shows a sensitivity of 14.08 and 11.34 for compressive and tensile strain, respectively. Inspired by the significant sensitivity, the fabricated device has been examined for human motion monitoring by attaching it to the human hand for practical usage in real-time applications. The proposed antenna-based sensor reduces the number of components by eliminating external wiring and onboard battery. Moreover, it serves as both the sensing and wireless data transmitting element. Overall, this work demonstrates designing a compact, easy-to-fabricate, sensitive, and flexible antenna-based Internet of Things (IoT) sensor for motion detection, structural health monitoring, and industrial strain sensing applications.