Showing papers in "Progress in Electromagnetics Research C in 2022"
TL;DR: In this article , a sub-6 GHz microstrip patch antenna operating at three resonant frequencies 3.6, 3.9, and 4.9 GHz is designed for 5G applications.
Abstract: |A novel recon(cid:12)gurable sub-6 GHz microstrip patch antenna operating at three resonant frequencies 3.6, 3.9, and 4.9 GHz is designed for 5G applications. The proposed antenna is constructed from metamaterial (MTM) array with a matching circuit printed around a printed strip line. The antenna is excited with a coplanar waveguide to achieve an excellent matching over a wide frequency band. The proposed antenna shows excellent performance in terms of S 11 , gain, and radiation pattern that are controlled well with two photo resistance. The proposed antenna shows different operating frequencies and radiation patterns after changing the of photo resistance status. The main antenna novelty is achieved by splitting the main lobe that tracks more than one user at the same resonant frequency. Nevertheless, the main radiation lobe can be steered to the desired location by controlling the surface current motion using two varactor diodes on a matching circuit.
10 citations
TL;DR: In this paper , a new frequency tunable filtering-antenna (so-called filtenna) is inspired by a Defected Ground Structure (DGS) band-pass filter for the fifth generation picocell base stations.
Abstract: In this paper, a new frequency tunable filtering-antenna (so-called filtenna) is inspired by a Defected Ground Structure (DGS) band-pass filter for the fifth generation picocell base stations. It is intended for use in Cognitive Radio (CR) communications within the European Union Sub-6GHz spectrum, which ranges between 3.4 and 3.8GHz. Firstly, a Wideband (WB) monopole antenna is proposed where the operational frequencies cover 3.15–4.19GHz, taking the 10-dB return loss level as a threshold. A band-pass filter of a Semi-Square Semi-Circle shape is integrated into the WB antenna ground to obtain the communicating filtenna. The narrowband frequency tunability is achieved by changing two varactor diode capacitances located in the filter slots. The antenna is prototyped occupying a total space of 60 × 80 × 0.77mm3, then tested to verify the simulated results. Three operating frequencies 3.4, 3.6, and 3.8GHz of the filtenna are studied in terms of return loss, realized gain, and radiation patterns which verify that the frequency shift has almost no effect on the antenna performance. The filtenna has a maximum gain of 4.5 dBi in measurements and 3.47 dBi in simulations. The obtained results have proved their efficiency for CR communications.
6 citations
TL;DR: In this paper , a two-step learning-by-examples (LBE) strategy based on support vector regression (SVR) is proposed to learn the complex relation among the heterogeneous parameters of the power plant.
Abstract: |In this paper, an innovative machine learning ( ML ) approach for the prediction of the output power generated by photovoltaic ( PV ) plants is presented. Toward this end, a two-step learning-by-examples ( LBE ) strategy based on support vector regression ( SVR ) is proposed to learn the complex relation among the heterogeneous parameters affecting the energy production of the power plant. More speci(cid:12)cally, the (cid:12)rst step is aimed at down-scaling the weather forecasts from the standard air temperature and the solar irradiance to the local module temperature and the plane-of-array ( POA ) irradiance. Then, the second step predicts the output power pro(cid:12)le given the down-scaled forecasts estimated at the previous step. The advantages and limitations of the proposed two-step approach have been experimentally analyzed exploiting a set of measurements acquired in a real PV plant. The obtained results are presented and discussed to point out the capabilities of the proposed LBE method to provide robust and reliable power predictions starting from simple weather forecasts.
5 citations
TL;DR: In this article , a planar monopole ultrawideband (UWB) antenna with continuously tunable notch band feature is presented, which has a compact size of 36.6× 26× 1mm3.
Abstract: In this work, a planar monopole ultrawideband (UWB) antenna with continuously tunable notch band feature is presented. The designed antenna, which has a compact size of 36.6× 26× 1mm3, is fabricated on a low-cost FR4 substrate and comprises a circular radiating patch with four rectangular defects, a microstrip feed line, and a partial ground plane to cover the UWB frequency band extending from 3.1GHz to 12.5GHz. A semi-elliptical slot is etched out from the circular patch to create the first notch band at 3.6GHz (WiMAX) in the UWB spectrum. The second notch band is created by embedding an annular slot on the circular patch loaded with a varactor diode to continuously tune the notch frequency from 5.6GHz to 7.7GHz in upper WLAN and X-band. To investigate the implementation feasibility of the designed UWB antenna, a prototype is fabricated and experimentally tested.
5 citations
TL;DR: In this article , a (cid:13)ower-shaped MIMO antenna with isolation improvement is proposed, which is made up of four symmetrical (Cid:2) 4 miniaturized radiating elements that are isolated using an orthogonal method.
Abstract: |A novel design of a 4 (cid:2) 4 miniaturized UWB-MIMO (multiple-input, multiple-output) antenna with isolation improvement is proposed in this paper. The designing procedure of a (cid:13)ower-shaped MIMO antenna is done using characteristic mode analysis (CMA). The (cid:13)ower-shaped UWB-MIMO antenna is made up of four symmetrical (cid:13)ower-shaped radiating elements that are isolated using an orthogonal method. The (cid:13)ower antenna’s dimensions are 40 (cid:2) 40 (cid:2) 1 : 6 mm 3 (0 : 44 (cid:21) 0 (cid:2) 0 : 44 (cid:21) 0 (cid:2) 0 : 017 (cid:21) 0 ). A (cid:13)ower-shaped radiator is used to get good the isolation in MIMO elements. Further isolation is enhanced by inserting a swastik-shaped stub on the ground to get return losses of S 11 < (cid:0) 10 dB and isolation of S 12 < (cid:0) 18 dB. The designed antenna covers the entire UWB (3.1 GHz{14 GHz) spectrum for impedance matching, including (10.7 GHz to 11.7 GHz), 11 GHz (10.7 GHz to 11.7 GHz), and 13 GHz (10.7 GHz to 11.7 GHz) (12.75 to 13.25 GHz). Good diversity performance is achieved in the UWB and ITU range. The designed antenna has a gain of 5.5 dB, an efficiency of 89%, an impedance bandwidth of 123.61%, an envelope correlation coefficient of 0.012, a diversity gain of nearer to 10 dB, a capacity channel loss of 0.29 bp/s/Hz, and a mean effective gain of less than (cid:0) 3 : 1 dB. The designed antenna is fabricated and tested. These simulated results are validated in state-of-the-art laboratories. According to the simulation and measurement results, this antenna is well suited for reliable wireless communication systems. The potentiality of the designed antenna is high, and the antenna is compact and portable.
4 citations
4 citations
TL;DR: In this article , an ultra-wideband compact printed log periodic dipole (LPD) array antenna is designed to operate between 500 MHz and 6 GHz frequencies with an average gain of 6 dBi and a very compact size.
Abstract: |This letter, an ultra-wideband compact printed log periodic dipole (LPD) array antenna is designed to operate between 500 MHz and 6 GHz frequencies. The proposed LPD antenna structure consists of one bow-tie dipole and 15 regular dipole elements. The bow-tie element is introduced to improve the antenna’s performance at the lowest frequencies below 1 GHz and at the same time to reduce the antenna size maintaining a good performance. An experimental antenna prototype has been designed, optimized, fabricated, numerically and experimentally assessed. The obtained results are very promising, and they demonstrated that the presented antenna prototype is able to operate in the range between 500 MHz and 6 GHz with an average gain of 6 dBi and a very compact size.
4 citations
TL;DR: In this article , a small substrate integrated waveguide (SIW) slot antenna for future (cid:12)fth generation (5G) communication systems is proposed, which works at 28 and 38 GHz.
Abstract: |In this paper, the authors propose a small substrate integrated waveguide (SIW) slot antenna for future (cid:12)fth generation (5G) communication systems. It works at 28 and 38 GHz. The proposed geometry consists of horizontal and vertical vias as well as a central circular ring. The cut slots in the etched center circular ring create a signi(cid:12)cant capacitive loading effect, lowering the lower resonating mode. Further, the introduced circular ring slot resonates on TE 101 and TE 102 modes at 28 and 38 GHz, respectively. The measured impedance bandwidths are 27.77{28.02 GHz and 37.99{ 38.10 GHz. Peak gains in the lower and upper bands are measured to be 6.96{7.15 dBi and 8.10{8.22 dBi, respectively. At 28 and 38 GHz, the observed half-power beam-widths (HPBWs) are 74 : 5 ◦ and 79 : 2 ◦ , respectively. Considering these performance results, such as single-layer dual-bands, high gain, small size, and good radiation efficiency, the designed SIW slot antenna is suitable for future millimeter-wave 5G applications.
4 citations
TL;DR: In this paper , a hexagonal cavity backed antenna based on HMSIW was proposed to operate at 5.2 GHz and 5.8 GHz frequencies, achieving a peak gain of 5.5 dB and 4.3 dB at center frequencies.
Abstract: |A hexagonal cavity backed antenna based on HMSIW is proposed to operate at 5.2 GHz and 5.8 GHz frequencies. The TM 010 and TM 110 modes of the hexagonal cavity resonator have been chosen to excite the structure. Afterwards, an HMSIW hexagonal cavity is formed by splitting conventional hexagonal cavity resonator along a magnetic wall. This enables a 50% reduction in size without affecting the antenna operating frequency. A rectangular slot is etched at the centre of the magnetic wall to curtail TM 110 mode operating frequency. The dimensions of the slot are optimized to adapt TM 110 resonant frequency to the desired frequency. In free space, the resulting antenna accomplished a peak gain of 5.5 dB and 4.3 dB at centre frequencies of 5.2 GHz and 5.8 GHz, respectively. In the vicinity of pork tissues, the antenna exhibits a peak gain of 4 dB at 5.8 GHz along with an efficiency of 87.2%.
4 citations
TL;DR: In this paper , the authors proposed an antenna with a defected ground structure (FRDGS) for 4G and 5G conformal portable devices and multi-band wireless systems.
Abstract: A compact (25×28×1.57mm3) and wide-band multimode frequency tunable antenna with a defected ground structure (FRDGS) for 4G and 5G conformal portable devices and multi-band wireless systems is presented in this article. In a previous study, frequency reconfigurable antenna designs only used the method of adding slots on the patch or ground. In this study, a combination of multiple slots, partial ground, and defective ground structure techniques are utilised to attain the advantages of compactness, wide impedance bandwidth, and steady radiation pattern. Multiple slots on the top layer of the substrate and F-shaped slot etched at the bottom make the proposed antenna. Two PIN diodes are inserted in the F-shaped slot for frequency reconfiguration, allowing the antenna to switch between different resonances. Ansys high frequency structure simulator 15.0v is used to simulate the antenna parameters. This antenna performance is demonstrated using measured and simulated data. The simulated and measured results clearly show that the proposed antenna can switch among six dissimilar resonant frequency bands via various modes of operation across the frequency spectrum from 2.3 to 8.9GHz. The antenna works in a variety of commercial bands, such as WLAN/Bluetooth (2.4– 2.5GHz), LTE/4G (2.3–2.7GHz), S-band (2–4GHz), Radio Navigation (2.7–2.9GHz), and 5G/sub-6 (3.3–4.9GHz), according to simulations and experiments. The proposed design features narrowband, wideband, and ultra-wideband properties with a consistent radiation pattern, adequate gain (1.6 to 5.8 dB), and high radiation efficiency (86 to 94%) in a small package. Furthermore, the performance comparison of the proposed antenna with that of the state-of-the-art antennas in terms of compactness, frequency reconfigurability, number of operating bands, and impedance bandwidth demonstrates the novelty of the proposed antenna and its potential application in multiple wireless applications.
4 citations
TL;DR: In this paper , the authors presented the structure and performance of a wearable antenna used in place of the ESP8266 Wi-Fi module antenna antenna in dresses, which provided a higher gain than 2 dBi. The proposed geometry utilizes rectangular patches with the inset feed method in the feedline segment, constructed using copper foil tape, 2.85 mm thick polyester as a substrate with a permittivity of 1.44 Defected Ground Structure (DGS) technique.
Abstract: |Wearable antenna is one component needed for mid-range communication. It can be integrated into clothing, bags, or any other item worn. This paper presents the structure and performance of a wearable antenna used in place of the ESP8266 Wi-Fi module antenna in dresses. With a higher gain than 2 dBi, this replacement will provide greater signal coverage than the existing Wi-Fi antenna module. The proposed geometry utilizes rectangular patches with the inset feed method in the feedline segment, constructed using copper foil tape, 2.85 mm thick polyester as a substrate with a permittivity ( " r ) of 1.44 Defected Ground Structure (DGS) technique. The operating frequency of the proposed antenna is at 2.4 GHz in the ISM (Industrial, Scienti(cid:12)c, and Medical) band. The whole process was used to optimize the structure, fabricated, and measured. The result of the simulation and measurement of the proposed antenna’s VSWR is less than 2. The measurements scenario for the substitute and existing antenna are divided into two categories: line-of-sight (LOS) and non-line-of-sight (NLOS). Each of them experiences the vertical and horizontal positions of the antenna. In LOS conditions, the vertical position has an average coverage of 9.84 meters more than the antenna module, and the horizontal position is 13.84 meters. In NLOS conditions, the horizontal position has an average coverage of 9.22 meters more than the EP8266 antenna module, which in the vertical condition is about 17.06 meters. The obtained data successfully demonstrated that the proposed antenna could signi(cid:12)cantly increase the coverage of the ESP8266 module.
TL;DR: In this paper , a compact low-pro(cid:12)le four and eight-element MIMO antenna arrays for 5G smartphone devices are presented, which can operate at two wide bands with triple resonance frequencies that cover the extended Personal Communication Purposes (PCS) n25 band and other related applications.
Abstract: |Compact low-pro(cid:12)le four and eight elements Multi-Input Multi-Output (MIMO) antenna arrays are presented for 5G smartphone devices. The proposed antenna systems can operate at two wide bands with triple resonance frequencies that cover the extended Personal Communication Purposes (PCS) n25 band and other related applications, the mobile china’s band, and the LTE Band-46. The proposed antenna element is designed based on modi(cid:12)ed Minkowski and Peano curves fractal geometries. Desirable antenna miniaturization with multi-band capability is obtained by utilizing the space-(cid:12)lling and self-similarity properties of the proposed hybrid fractal geometries where the overall antenna size is (11 : 47 mm (cid:2) 7 : 19 mm). All antennas are printed on the surface layer of the main mobile board. Based on the self-isolated property, good isolation is attained without employing additional decoupling structures and/or isolation techniques, increasing system complexity and reducing antenna efficiency. For evaluating the performance of the proposed antenna systems, the scattering parameters, antenna efficiencies, antenna gains, antenna radiation characteristics, envelope correlation coefficients (ECCs), and mean effective gains (MEGs) are investigated. The performances are evaluated to con(cid:12)rm the suitability of the proposed MIMO antenna systems for 5G mobile terminals. The proposed eight elements MIMO system has been fabricated and tested. The measured and simulated results are in good agreement.
TL;DR: In this paper , the concept and implementation of a compact dual-band microstrip slot antenna and its four-unit multiple-input-multiple-output (MIMO) implementation for sub-6 GHz utilizations is described.
Abstract: |This paper describes the concept and implementation of a compact dual-band microstrip slot antenna and its four-unit multiple-input{multiple-output (MIMO) implementation for sub-6 GHz utilizations. The proposed structure comprises a 50 ohm microstrip monopole on the top side with a defective ground structure (DGS) having semicircular and rectangular slots. This quad-element MIMO antenna has a size of 60 (cid:2) 60 (cid:2) 1 : 6 mm 3 . The proposed antenna provides wide impedance bandwidths of 23.7% (2.42 GHz to 3.07 GHz) for the (cid:12)rst band and 42.2% (4.14 GHz to 6.37 GHz) for the second band with a mutual coupling value less than (cid:0) 34 dB for the two bands. The antenna also provides a low envelope correlation coefficient, good antenna gain, and acceptable radiation efficiency across the frequency ranges.
TL;DR: In this article , a microstrip fractal patch antenna with a COVID-19 shape designed for wireless applications is presented, which operates and resonates on two frequencies 7.5 GHz and 17 GHz within C and Ku bands, respectively.
Abstract: This paper presents a novel unique microstrip fractal patch antenna with a COVID-19 shape designed for wireless applications. The COVID-19 antenna is a compact, miniature size, multiband, low weight, and low-cost patch antenna;the demonstrated patch antenna, simulated using the HFSS software program, consists of a circular printed patch with a radius of 0.4 cm surrounded by 5 pairs of crowns. The antenna is implemented on a double-sided copper plate with an FR4-epoxy substrate of 1 × 1 cm2 area and 1.6 mm thickness. This small patch operates and resonates on two frequencies 7.5 GHz and 17 GHz within C and Ku bands, respectively. The simulated and measured gains were respectively 0.8 dB and 0.2 dB at the lower frequency and 2.21 dB and 2 dB at the higher frequency. A coaxial probe feeding method is used in the simulation, and printed prototypes showed excellent consistency between measured and simulated resonance frequencies. © 2022, Electromagnetics Academy. All rights reserved.
TL;DR: In this paper , a novel multiband Fractal Reconfigurable Antenna (FRA) is presented and discussed using two RF PIN diodes as switching elements for electronic reconfiguration.
Abstract: Fractal and reconfigurable antennas are the need of modern wireless communication systems that operate under dynamic scenarios catering to the diversified needs of modern wireless applications. In this dissemination, a novel multiband Fractal Reconfigurable Antenna (FRA) is presented and discussed using two RF PIN diodes as switching elements for electronic reconfiguration. It is analyzed using equivalent circuit concept and investigated in terms of various antenna performance parameters. The proposed FRA can operate in various frequency bands resonating at four different frequencies with switchable bandwidth and gain. The highest gain is observed to be about 8.37 dB at 9.68GHz while the highest bandwidth is about 540MHz in the X-band. The simulation and measurement results obtained are found in agreement. The multiband characteristics of the proposed FRA make it useful for smart wireless communication applications in the S (2–4GHz), C (4–8GHz), and X (8–12GHz) microwave bands.
TL;DR: In this paper , the authors presented the design of a super wideband (SWB) antenna with enhanced bandwidth for microwave applications with a detailed parametric study of the methods used to enhance the bandwidth of the conventional antenna.
Abstract: |This paper presents the design of a Super Wideband (SWB) antenna with enhanced bandwidth for microwave applications with a detailed parametric study of the methods used to enhance the bandwidth of the conventional antenna. The proposed SWB antenna has emerged from a traditional circular monopole antenna by experimenting with an inscribed fractal structure with a tapered feed line and partial ground plane with blended corners and achieved a super wideband frequency range from 2.31 GHz to 105.5 GHz with a fractional bandwidth of 192.1% and a Bandwidth Dimension Ratio (BDR) of 2154.88. The antenna has a relatively small electrical dimension, i.e., 0.33 (cid:21) 0 (cid:2) 0 : 27 (cid:21) 0 , where (cid:21) 0 corresponds to the lower-end operating frequency and exhibits good gain and efficiency characteristics. In order to observe the signal correlation of the proposed antenna, the time domain analysis using similar antennas in face-to-face and side-to-side scenarios has been performed using the EM simulation tool CST-STUDIO. The simulated gain varies from 1.28 to 9.35 dBi. The proposed antenna can be used for S, C, X, Ka, Ku, V, and W bands for microwave and millimetre wave applications. The simulated and measured results of the proposed antenna exhibit a good agreement.
TL;DR: In this paper , a high performance substrate integrated waveguide (SIW) slotted array antenna with low sidelobe level and optimum gain at 28 GHz is designed, and experimental results are presented with simulated data.
Abstract: |A high performance substrate integrated waveguide (SIW) slotted array antenna with low sidelobe level and optimum gain at 28 GHz is designed, and experimental results are presented with simulated data. In order to achieve a low sidelobe level, Chebyshev power coefficients in the form of slot displacements are applied to the SIW array antenna. A MATLAB program has been written to (cid:12)nd these slot displacements. This work entails investigating and designing the optimum microstrip to SIW transition over the Ka-band, designing a 1 (cid:2) 8 slotted SIW array antenna, and (cid:12)nally applying the Chebyshev power coefficients to the slots of the 1 (cid:2) 8 SIW array antenna. The fabricated prototype of a 1 (cid:2) 8 SIW slotted array antenna is tested, and its performance is studied in terms of gain and half power beam width (HPBW), compared with simulations. The measured results of the 1 (cid:2) 8 slotted SIW array antenna at 28 GHz have a j S 11 j of better than (cid:0) 20 dB, a gain of 13 dB, and an HPBW of 17 ◦ . The overall dimensions of the design at 28 GHz are 7 : 143 mm (cid:2) 51 : 8 mm (cid:2) 0 : 254 mm (0 : 667 (cid:21) o (cid:2) 4 : 84 (cid:21) o (cid:2) 0 : 023 (cid:21) o = 0 : 0766 (cid:21) 3 o mm 3 ).
TL;DR: In this article , a dual-mode dual-band square cavity substrate integrated waveguide (SIW) bandpass filter is proposed, where metalized via-holes are inserted into the center of the cavity as perturbations to move and control the four resonant modes to create the dual passband filter.
Abstract: A tunable dual-mode dual-band square cavity substrate integrated waveguide (SIW) bandpass filter is proposed. Metalized via-holes are inserted into the center of the cavity as perturbations to move and control the four resonant modes to create the dual passband filter. The first passband is formed by the perturbed TE201 and TE202 modes, while the second passband is formed by the perturbed TE301 and TE302 modes. Moreover, moving the perturbed via-holes on the SIW cavity allows the first passband to be tuned separately while the second passband is almost fixed. A dualband filter prototype with frequencies of 17GHz and 19.36GHz and three transmission zeros (TZs) has been designed, fabricated, and measured. The measured and simulated results are in good agreement, confirming the proposed dual-band filter design concept.
TL;DR: In this paper , a novel metamaterial-based circular patch multi-input multi-output (MIMO) antenna is designed with a C-shaped defected ground structure for high isolation.
Abstract: |A novel metamaterial-based circular patch multi-input multi-output (MIMO) antenna is designed with a ‘C’-shaped defected ground structure for high isolation. A 4 (cid:2) 4 mm 2 unit cell for a ring resonator has been designed and exhibited double negative material (DNG) properties from 1.0 to 2.92 GHz and 13.68 to 17.67 GHz and Mu negative material (MNG) from 4.70 to 13.67 GHz. The proposed antenna structure is designed by embedding the ring resonator-based meta-structure to a circular patch antenna and fabricated with dimensions 0 : 245 (cid:21) 0 (cid:2) 0 : 409 (cid:21) 0 (15 (cid:2) 25 mm 2 ). The proposed antenna operating at 8.50 to 14.23 GHz for X and lower Ku bands is used in the Unmanned Arial Vehicle (UAV’s) applications. The spacing between elements is 0 : 088 (cid:21) 0 (5.4 mm) on an FR4 epoxy substrate, and the ‘C’-shaped structure on the back of the antenna improves the isolation of more than 24 dB in the operating band. Distance between the antenna elements plays a crucial role, and parameters affected by this are optimized by introducing machine learning. For future predictions, a linear regression model was created to optimize the parameters’ linear dependencies like isolation and return loss on the distance between the antenna elements. The radiation efficiency and gain of the antenna are enhanced by 92% and 6.02 dB at 13.22 GHz, respectively. The MIMO antenna’s simulated results of diversity and other parameters are in the acceptable range with the measured results used for X-band radar applications. The proposed decoupling technique is simple to understand and implement.
TL;DR: In this paper , a dual-band split ring monopole antenna structure for 5G sub-6 GHz and WLAN applications is proposed, which is optimized to provide S 11 (cid:20) (cID:0) 10 dB over 3.3{3.6 and 5.5{5.9 GHz.
Abstract: |In this paper, dual-band split ring monopole antenna structures for 5G sub-6 GHz and WLAN applications are proposed. The antenna structures are designed from a rectangular annular ring monopole antenna. A compact dual rectangular split ring monopole antenna is designed to operate over dual bands. The two split rings are connected through a common arm. The structure is optimized to provide S 11 (cid:20) (cid:0) 10 dB over 3.3{3.6 GHz and 5.15{5.5 GHz for 5G and WLAN applications. In the second dual-band antenna, a slot is cut in one of the arms to form another closed rectangular ring to further reduce the dimensions of the antenna. This structure provides S 11 (cid:20) (cid:0) 10 dB over 3.3{3.6 and 5.5{5.9 GHz for 5G, WLAN and V2X applications. The two bands can be easily controlled as the dimensions of two rings determine the resonant frequencies of the two bands, and one of the arms of a ring is unresponsive to lower band and affects upper band only. Both antennas offer nearly omnidirectional radiation patterns in both bands. The two prototype antennas are fabricated on a 0.17 (cid:21) 0 (cid:2) 0 : 19 (cid:21) 0 and 0.15 (cid:21) 0 (cid:2) 0 : 19 (cid:21) 0 FR4 substrate, where (cid:21) 0 is the free-space wavelength corresponding to 3.3 GHz. The measured results agree with the simulated ones.
TL;DR: In this paper , the optimal working frequency of the 1m whip antenna when being immersed in seawater at 0.25m, 0.5m, and 0.75m was derived.
Abstract: In order to analyze the working status of the underwater unmanned vehicle not fully surfaced, the optimal working frequency when the whip antenna radiates the maximum power is given. The input impedance of the antenna on the water is theoretically calculated. It is regarded as the load of the underwater part of the antenna, and the total input impedance of the whip antenna is obtained. The relationship between the antenna radiated power to the external field and the input power is analyzed, and the optimal operating frequency corresponding to the maximum radiated power is determined. Using simulation experiments and actual measurements, the radiated power of the 1m whip antenna when being immersed in seawater at 0.25m, 0.5m, 0.75m is obtained, and the corresponding optimal working frequency is calculated, which are in good agreement with the theoretical deduction results. The results show that as the depth of the antenna immersed in seawater increases, the power radiated from the antenna to the external field decreases, and the optimal working frequency increases accordingly.
TL;DR: In this article , a planar compact antenna composed of two crossed Cornu spirals is presented, where each Cornu spiral is fed from the center of the linearly part of the curvature between the two spirals, which builds the clothoid.
Abstract: A new planar compact antenna composed of two crossed Cornu spirals is presented. Each Cornu spiral is fed from the center of the linearly part of the curvature between the two spirals, which builds the clothoid. Sequential rotation is applied using a sequential phase network to obtain circular polarization and increase the effective bandwidth. Signal integrity issues have been addressed and designed to ensure high quality of signal propagation. As a result, the antenna shows good radiation characteristics in the bandwidth of interest. Compared to antennas of the same size in the literature, it is broadband and of high gain. Although the proposed antenna has been designed for Kand Ka-band operations, it can also be developed for lower and upper frequencies because of the linearity of the Maxwell equations.
TL;DR: In this paper , a quad-band notch characteristics ultra-wideband (UWB) antenna for Wi-MAX, L-WLAN, U-Wlan, and C-band applications is presented.
Abstract: |In this paper, a quad-band notch characteristics ultra-wideband (UWB) antenna for Wi-MAX, L-WLAN, U-WLAN, and C-band applications is presented. The initial UWB antenna bandwidth is achieved in the 2 to 12.5 GHz frequency band by using the partial ground method. Spiral lossy resonator (SLR) slots are loaded into the UWB ground structure to achieve quad-band notch characteristics. Each SLRS circuit is accountable for a single notch characteristic by losing EM power at the notch frequency. A quad-band notch is accomplished in this antenna for WiMAX (3.24 to 3.56 GHz), L-WLAN (4.76 to 5.34 GHz), U-WLAN (5.58 to 5.91 GHz), and C-band (7.37 to 7.71 GHz) by loading four SLR slots circuits into the UWB antenna. The proposed antenna is engraved on a Rogers RO4003C (3.55) substrate having an overall volume of 50 (cid:3) 40 (cid:3) 1 : 524 mm 3 . The proposed antenna’s performance has been veri(cid:12)ed through simulation and experiments.
TL;DR: In this article , a low-pro(cid:12)le dual circularly polarized (CP) antenna for Ku band satellite communication is proposed, where a quarter-mode SIW is designed as a circular polarization unit, which realizes circular polarization by using high-order mode TE 130 , and a pair of units are combined to form the antenna proposed in this paper.
Abstract: |In this paper, a low-pro(cid:12)le dual circularly polarized (CP) antenna for Ku band satellite communication is proposed. A quarter-mode SIW (QMSIW) is designed as a circular polarization unit, which realizes circular polarization by using high-order mode TE 130 , and a pair of units are combined to form the antenna proposed in this paper. Feeding different units can realize left-handed circular polarization and right-handed circular polarization, respectively. The antenna impedance bandwidth is 5.66 GHz (15.16 GHz{20.82 GHz); the circular polarization bandwidth (CPBW) is 540 MHz (15.64 GHz{ 16.18 GHz); and the gain in the passband is 5.1 dBi, with a minimum axial ratio (AR) of 1 dB. The thickness of the antenna is only 1.5 mm, which has obvious low-pro(cid:12)le characteristics.
TL;DR: In this paper , the authors proposed a compact UWB antenna with a recon(cid:12)gurable and sharp dual-band notches to cancel the interference with some critical applications (5G WLAN, and X-band satellite downlink) for underlay cognitive radio (CR) applications.
Abstract: |In this paper, a compact UWB antenna with a recon(cid:12)gurable and sharp dual-band notches (cid:12)lter to cancel the interference with some critical applications (5G WLAN, and X-band satellite downlink) is proposed for underlay cognitive radio (CR) applications. The dual notched bands are produced by coupling a pair of (cid:25) -shaped resonators on both sides of the feed line and by etching a U-slot inside the feed line of the antenna. The proposed UWB (cid:12)ltenna in this con(cid:12)guration has a surface area of 22 (cid:2) 31 mm 2 and produces simulated (measured) recon(cid:12)gurable notched frequencies at 5.466 GHz (5.7 GHz) and 7.578 GHz (7.44 GHz) with an impedance bandwidth of 3.024{10.87 GHz (2.825{10.74 GHz). Three PIN diodes are used to switch the presence of the dual-band notch. Two PIN diodes that turn ON-OFF simultaneously ( D 1 A & D 1 B ) are inserted within a pair of (cid:25) -shaped resonators to control the 5G WLAN band notch, and a single diode ( D 2 ) is embedded within a quarter wavelength resonator which is located inside the feed line of the antenna for controlling the X-band band notch. The simulation and measured results reveal that the proposed (cid:12)ltenna effectively covers UWB with controlled cancellation for interference with the intended bands. The realized gain is 4.5 dBi through the passband except in the notched frequencies, where it is decreased to less than (cid:0) 11 dBi in both notch frequencies. In other words, the proposed (cid:12)ltenna has a very high VSWR of greater than 20 at the notched notched frequency. The simulated and measured results demonstrate that the (cid:12)ltenna has a low re(cid:13)ection coefficient ( S 11 ) and sharp VSWR at the notched frequencies which means an excellent band rejection behavior.
TL;DR: In this article , a four-port Wrench-shaped compact UWB MIMO antenna with a novel decoupling network in the ground plane is presented for 3.1{10.6 GHz.
Abstract: |This present article reports a high isolation four-port Wrench shaped compact UWB MIMO antenna with a novel decoupling network in the ground plane, and its step-by-step evolution is presented for 3.1{10.6 GHz. The proposed four-port MIMO antenna is fabricated on an FR4 substrate of size 44 (cid:2) 44 mm 2 (0 : 342 (cid:21) 0 (cid:2) 0 : 342 (cid:21) 0 ), where (cid:21) 0 is a free space wavelength at 2.33 GHz, with 7 mm edge-to-edge spacing between the radiating elements. It consists of four orthogonal symmetrically placed identical radiating elements each of which has a Wrench-shaped circular patch with a rectangular slot cut in the partial ground. The performance characteristics of this MIMO antenna are re(cid:13)ection coefficients S 11 (cid:20) (cid:0) 10 dB in the range from 2.33 GHz to 11.7 GHz, mutual coupling coefficients S 21 (cid:20) (cid:0) 28 : 24 dB, and S 31 (cid:20) (cid:0) 22 : 35 dB. The maximum peak gain is 5.15 dBi at 9.2 GHz, and minimum is 1.27 dBi at 3.1 GHz. The efficiency GHz, the minimum at GHz. diversity parameters of proposed four-port MIMO antenna are as ECC (cid:20) 0 : 2, DG (cid:20) TARC (cid:20) (cid:0) 10 dB, the ratio of MEG between any two elements is near unity, and CCL < 0 : 38 bits/s/Hz in the band of interest. The design is fabricated and measured. The measured and simulated results are in good agreement and are within
TL;DR: In this article , a tri-band bandpass filter (BPF) with controllable bandwidths is presented, where T-shaped short-and-open stubs have alternating positions to use the maximally flat theory, based on the overall ABCD parameters.
Abstract: Designing a multi-band bandpass filter (BPF) with controllable bandwidths is an alternative process to several technologies suggested by researchers. Hence, this paper presents a tri-band BPF in microstrip technology where T-shaped short-and-open stubs have alternating positions to use the maximally flat theory, based on the overall ABCD parameters of the circuit. The combination of the design Q-factor and operating frequency to mismatch the design is the technique basis. The proposed structure comprises quarter wavelength (λ/4) line section to develop a tri-band BPF frequency. All stubs are symmetrical relative to the center axis, while the prototype has been fabricated on a wafer of 22.42×7.62mm2. Using an FR4 HTG-175 with a thickness 1-mm, dielectric constant εr = 4.4, and loss tangent tan δ = 0.02, the (4.06–4.283)GHz, (5.877–6.408)GHz, and (14.281–14.589)GHz are obtained referring to a 10-dB of the return loss. In contrast, the insertion losses at the center frequencies are 2.107/1.354/4.08 dB and the fractional bandwidths of 2.134%, 5.346%, and 8.645%, respectively. This covers WAS (including RLAN), ISM, and 5G applications. However, the attenuation coefficient is between 1.326 dB and 4.368 dB. The tri-band BPF prototype was validated using the Anritsu MS4642B 20GHz Vector Network Analyzer. The measured and E-simulated results have been compared with good agreement.
TL;DR: In this article , a wideband polarization diversity multiple-input multiple-output (MIMO) antenna array for 5G smart mobile devices is proposed, where the octagon-shaped resonant slots are etched from the bottom (ground) layer of the main mobile board.
Abstract: |In this paper, we propose a wideband polarization diversity multiple-input multiple-output (MIMO) antenna array for 5G smart mobile devices. The proposed MIMO antenna array consists of 8-ports dual-polarized L-shaped lines that highly excite radiating slots, where the elements are placed at four-corners of a compact mobile unit of size 75 (cid:2) 150 mm 2 . The uniqueness of the proposed MIMO antenna structure comes from the deployment of octagon-shaped resonant slots within the metallic ground plane, i.e., the octagonal-slots are etched from the bottom (ground) layer of the main mobile board. Due to the unique slots in the ground plane, wideband impedance has been achieved (3.38{ 3.8 GHz at (cid:0) 6-dB threshold). The proposed smart phone 8 (cid:2) 8 diversity MIMO antenna is designed to support the spectrum of commercial sub-6 GHz 5G communications and cover the frequency range of around 3.5 GHz band with high decoupling between antenna ports. The proposed array is designed, numerically simulated, fabricated, and tested. Good agreement between simulated and measured results was achieved. The MIMO antenna has a satisfactory far-(cid:12)eld performance along with very low envelope correlation coefficient (ECC) < 0 : 055, high diversity of more than 9.95, and very low speci(cid:12)c absorption rate ( < 1 W/kg for a 10-g human tissue).
TL;DR: In this paper , a multi-cavity two-mode dual-passband (cid:12) operator operating in X-band is proposed, which uses TE 201 mode in the substrate integrated waveguide (SIW) cavity and the TE 101 mode in HMSIW cavity.
Abstract: |In order to effectively improve (cid:12)lter selectivity and out-of-band rejection level, a multi-cavity two-mode dual-passband (cid:12)lter operating in X-band is proposed. By designing a suitable circuit topology, the bandpasss of the (cid:12)lter are formed using TE 201 mode in the substrate integrated waveguide (SIW) cavity and the TE 101 mode in the half mode substrate integrated waveguide (HMSIW) cavity. In addition, incorporating a T-slot structure in the dual-mode SIW cavity can add additional transmission zeros (TZs) and improve the (cid:12)lter selectivity while achieving miniaturization. The center frequencies of the two passbands are 8.67 GHz and 11.52 GHz, respectively. The inter-band isolation is better than 65 dB with three transmission zeros and maximum insertion loss of 0.48 dB and 0.31 dB, respectively. The proposed (cid:12)lter has a compact structure, low insertion loss, high-frequency selectivity, and the measured results agree with the simulated ones.