Coupled Patch Research Articles

A quad-polarization reconfigurable transmitarray antenna with beam-scanning and reconfigurable polarization capabilities

Abstract In this paper, a novel quad-polarized electronically reconfigurable transmitarray antenna(QRTA) is proposed, which can actively switch among four linear-polarization modes and steer beam-scanning in these polarization modes. The QRTA element follows a receiving-transmitting structure. Its receiver or transmitter is composed of four rotationally symmetric patches and a coupling patch. Four rotationally symmetric patches generate x- and y-polarization modes, while coupling patches on the top and bottom layers of the QRTA element are designed to synthesize x-, 45◦-, y-, and 135◦-polarization modes. The QRTA element utilizes a reverse symmetry current method to achieve a 180◦ phase difference in the radiated electromagnetic waves. By manipulating the state of the p-i-n diodes, the proposed QRTA element can achieve four LP functions and a 1-bit phase shift. Based on the proposed novel QRTA element, a 10 × 10 elements QRTA prototype is fabricated and measured. The measured results demonstrate that the proposed QRTA can electronically switch between four LP modes and achieve beam-scanning in those LP modes. The proposed QRTA shows several advantages, including low cost, multi-polarization capability, high gain, and beam-scanning, which means that it can enhance the polarization capabilities and intelligence of wireless communication systems.

W‐band inline waveguide‐to‐coupled microstrip line transition using a compact differential antenna

AbstractHere, a transition technique for converting signals from rectangular waveguide to coupled microstrip lines (CML) is presented, which provides a solution for differential antenna array feeding of automotive radar. The key to the proposed transition structure is to connect the coupling patches together with a short‐bridge structure, thus forming a quasi‐loop structure. Through the short bridge, the radiation efficiency of the antenna is greatly enhanced, and the mode conversion from TE10 of rectangle waveguide to differential mode of coupled microstrip line is realized effectively under the extremely compact size. Finally, the designed transition structure is manufactured and measured. The experimental results show that the back‐to‐back insertion loss is lower than 0.65 dB and the return loss is higher than 16.8 dB in the W‐band (75–110 GHz), which is the best performance and the simplest design among the relevant transition transitions reported so far.

Wideband Stacked Tightly Coupled Patch Array With Parasitic Strips

Wideband Stacked Tightly Coupled Patch Array With Parasitic Strips

Wideband Decoupled Asynchronously Coupled Patch Antennas

Wideband Decoupled Asynchronously Coupled Patch Antennas

Higher Order Bandpass Single and Dual Band Frequency Selective Surfaces With Aperture Coupled Patch Resonators

Higher Order Bandpass Single and Dual Band Frequency Selective Surfaces With Aperture Coupled Patch Resonators

Multi-polarized Fabry-Pérot resonator cavity using multilayer partially reflective metasurface in X-Band

In this paper, we propose a multi-polarized Fabry-Pérot resonator cavity (MPFPRC) by integrating the multilayer partially reflective metasurface (MPRM), the feed of multi-polarized slot coupling patch antenna and the reflective ground in X-Band. The MPRM consists of first-layer square metal patches, second-layer metal ground with square slots, third-layer square metal patches and fourth-layer partially reflective patches. Based on the MPRM, the proposed MPFPRC is capable of transforming 0°, 45° and −45° linearly polarized (LP) waves emitted by the feed into LP beam, left-handed circularly polarized (LHCP) beam and right-handed circularly polarized (RHCP) beam, respectively. Finally, the designed MPFPRC is simulated, processed and measured. The experimental results verify that the −3 dB gain bandwidth of LP is 9.1–10.2 GHz, the −3 dB gain bandwidth and 3 dB axial ratio bandwidth of the LHCP are 9.0–10.0 GHz and 9.2–10.0 GHz, and the −3 dB gain bandwidth and 3 dB axial ratio bandwidth of the RHCP are 9.0–10.0 GHz and 9.3–10.0 GHz.

A circularly polarized phased array antenna with 60° scanning in the D-plane using a top-loaded patch

The requirements for circularly polarized (CP) phased array antennas are growing with the rapid development of electronic systems. To achieve a low-profile, wideband, and large scanning-angle CP, we constructed a novel CP unit cell with a two-layer folded coupling patch and a top-loaded patch. The design of the folded coupling patch was based on the principle of reverse current cancellation. Compared with the single-layer coupling patch, the folded coupling patch suppressed the occurrence of strong in-band resonance and obtained a wider axial ratio (AR) bandwidth. To solve the problem of AR performance deterioration in the D-plane scanning, we introduced the top-loaded patch to replace the thick wide-angle impedance matching layer, which improved the difference in co-polarization components and reduced cross-polarization level. Thus, a large scanning angle of more than 60° in the D-plane was obtained. An 8 × 8 planar array based on the proposed CP unit cell was designed. The array achieved a 3.9:1 (3.2–12.5 GHz) AR bandwidth and up to 60° scanning angle in the D-plane and 70° in the E-/H-plane; an AR smaller than 3 dB was demonstrated over the entire scanning range.

A wide‐angle beam scanning circularly polarized, tightly coupled dipole array based on two‐layer parasitic ring structure elements

In this paper, a wide-angle beam scanning circularly polarized (CP) phased array element, which consists of a concentric tightly coupled dipole array (TCDA) element with a two-layer parasitic ring structure and a wideband 90° phase shifter, is proposed. To solve the problem of the scanning blindness zone caused by a concentric layout, the grounded coupling patch for the traditional TCDA element is ‘split’ into a combination of a grounded parasitic ring and coupling patch. This combination structure can not only suppress the in-band common-mode resonance but also destroy the scanning blind zone mode formed by the dipole and grounded coupling patch. In addition, a two-layer parasitic ring structure is introduced to obtain a wider axial ratio (AR) beamwidth relative to a single-layer structure, so a wide-angle beam scanning AR is realized. An 8 × 8 left-handed CP planar array based on the proposed wide-angle beam scanning CP elements is designed and prototyped. Results show that the array can operate over a 3.2:1 (3.75–12.0 GHz) overlapping bandwidth, meeting an AR < 3 dB in the main beam and an active voltage standing wave ratio <2.8 within a ±60° angle scanning range.

A Low Profile, Broadband Circularly Polarized Beam Scanning Array

Based on the idea of tightly coupled dipole array, a low profile, broadband circularly polarized array is designed in this paper. The circularly polarized phased array element consists of dual polarized dipoles with the same phase center and orthogonal arrangement, grounded coupling patches, resistive frequency selective surfaces (RFSS), and a 90° phase shifter network. In order to realize broadband scanning, the effect of RFSS on the input active voltage standing wave ratio and radiation axial ratio (AR) of the element is studied. The results show that the element can operate at 5-11.5GHz, within a ±45° angle scanning range, the AR of each scanning plane is less than 3dB, and the profile height is only 0.33 λ high.

3D-bioprinted peptide coupling patches for wound healing.

Chronic wounds caused by severe trauma remain a serious challenge for clinical treatment. In this study, we developed a novel angiogenic 3D-bioprinted peptide patch to improve skin wound healing. The 3D-bioprinted technology can fabricate individual patches according to the shape characteristics of the damaged tissue. Gelatin methacryloyl (GelMA) and hyaluronic acid methacryloyl (HAMA) have excellent biocompatibility and biodegradability, and were used as a biomaterial to produce bioprinted patches. The pro-angiogenic QHREDGS peptide was covalently conjugated to the 3D-bioprinted GelMA/HAMA patches, extending the release of QHREDGS and improving the angiogenic properties of the patch. Our results demonstrated that these 3D-bioprinted peptide patches showed excellent biocompatibility, angiogenesis, and tissue repair both in vivo and in vitro. These findings indicated that 3D-bioprinted peptide patches improved skin wound healing and could be used in other tissue engineering applications.

A Novel Miniaturized Multiband Strong Coupled-FSS Structure Insensitive to Almost All Angles and All Polarizations

This article presents a novel miniaturized almost all-angle-insensitive strong coupled frequency-selective surface (SC-FSS) with all-polarization-insensitive multiband by introducing the different interlayer coupling patches. Two templates of a single passband and a dual passband with unit cell less than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.03\lambda $ </tex-math></inline-formula> are adopted to bring in two stopbands on both ends of each passband. Furthermore, the corresponding equivalent circuit models are developed to explain the physical mechanism and formulate relevant design equations. Finally, a prototype of the proposed dual-passband structure is fabricated and measured to verify the results of full-wave simulation and theoretical analysis. The experiment results show that there are a lower passband working at 2 GHz and a higher passband at 5.8 GHz with a lower stopband at 4 GHz and a higher at 7.5 GHz at the ends of above passbands, respectively, which exhibits the stable performance against the variation of the incident angles (from 0° to 86°) for both TE and TM polarizations. The measurement results demonstrate that the proposed multiband SC-FSS is a good candidate for designing a high-performance antenna radome for solving electromagnetic interference (EMI) problems.

Fully integrated wideband phased array with large scan range and 5:1 bandwidth

In this work, a fully integrated phased array using multi-layer printed circuit board (PCB) fabrication technologies is presented. This array is directly fed by 50 Ω coaxial cables, without balanced-to-unbalanced transitions. An asymmetric dipole is used to achieve stable input impedance. Furthermore, to broaden the operating bandwidth, a coupling patch is designed beneath the asymmetric dipole , which also eliminates the common-mode resonance and decreases the array profile. In addition, three wide-angle impedance matching (WAIM) layers with different structures are utilised to improve the scan range in all scanning planes. Infinite array simulations indicate that the proposed array can operate over a 5.1:1 bandwidth (2.4 ∼ 12.2 GHz) with an active voltage standing wave ratio below 3 while scanning up to ± 60° in H plane and ±75° in the E plane. Furthermore, the proposed antenna, whose cross-polarization levels remain below −35 and −7.5 dB when scanning up to 75° in the E plane and 60° in the D plane, demonstrates the merits of high polarization purity. Array simulations are verified by the measurements of a 12 × 12 prototype, and good agreement is observed.

A Novel Wideband Transition from Substrate Integrated Waveguide to Rectangular Waveguide

Aim: In this article, wideband Substrate Integrated Waveguide (SIW) and rectangular waveguide (RWG) transition operating in Ka-band is proposed. Objective: To design wideband Substrate Integrated Waveguide (SIW) and rectangular waveguide (RWG) transition operating in Ka-band. Method: The coupling patch was etched on the SIW cavity to couple the electromagnetic energy from SIW to RWG. Moreover, metasurface was introduced into the radiating patch to enhance bandwidth. To verify the functionality of the proposed structure back to back transition was designed and fabricated on a single layer substrate using standard Printed Circuit Board (PCB) fabrication technology. Results: Measured results match with the simulation results, measured insertion loss was less than 1.2 dB and return loss was better than 3 dB for the frequency range of 28.8 to 36.3 GHz. By fabricating transition with 35 SRRs, bandwidth of the proposed transition can be improved. Conclusion: The proposed transition has advantages like compact size, easy to fabricate, low cost and wide bandwidth. The proposed structure is a good candidate for millimeter-wave circuits and systems.

Simple Model to Investigate a Three Layer Electromagnetically Coupled Equilateral Triangular Patch Antenna for Enhancement in Bandwidth and Gain

An analytical model is proposed for computing the resonant frequency, quality factors, bandwidth, input impedance, and gain of electromagnetically coupled stacked equilateral triangular patch antennas. The model is simple, fast, and suitable to apply directly in the computer-aided design (CAD) programs. The accuracy of the present model is computed against our newly performed and previously reported experimental results for various sets of relative permittivity and thickness of microstrip structure. We have also employed commercial software to validate the model.

Isogeometric Bézier dual mortaring: The Kirchhoff–Love shell problem

In this paper we develop an isogeometric Bézier dual mortar method for coupling multi-patch Kirchhoff–Love shell structures. The proposed approach weakly enforces the continuity of the solution at patch interfaces through a dual mortar method and can be applied to both conforming and non-conforming discretizations. As the employed dual basis functions have local supports and satisfy the biorthogonality property, the resulting stiffness matrix is sparse. In addition, the coupling accuracy is optimal because the dual basis possesses the polynomial reproduction property. We also formulate the continuity constraints through the Rodrigues’ rotation operator which gives a unified framework for coupling patches that are intersected with G1 continuity as well as patches that meet at a kink. Several linear and nonlinear examples demonstrated the performance and robustness of the proposed coupling techniques.

Broadband Modified Proximity Coupled Patch Antenna with Cavity-Backed Configuration

A modified proximity-coupled microstrip patch antenna with broad impedance bandwidth is proposed by incorporating proximity-coupled patch antenna into the rectangular open-ended microstrip feed line on a cavity structure. First we design a proximity-coupled microstrip antenna to have a wide bandwidth in the lower band centered at 7 GHz using a cavity-backed ground. To broaden the bandwidth of the antenna to the upper band, we then apply a rectangular open-ended microstrip feed line, adjusting the relative position to the cavity to generate an additional resonance close to 10 GHz. The combination of lower and upper band design results in a broadband antenna with dimensions of 30 mm × 30 mm × 9 mm (0.9λ&lt;sub&gt;0&lt;/sub&gt; × 0.9λ&lt;sub&gt;0&lt;/sub&gt; × 0.27λ&lt;sub&gt;0&lt;/sub&gt;) is designed where λ&lt;sub&gt;0&lt;/sub&gt; corresponds to the free space wavelength at a center frequency of 9 GHz. The measurement results verify the broad impedance bandwidth (VSWR ≤ 2) of the antenna at 77% (5.6–12.6 GHz) while the broadside gain is maintained between 6 dBi and 8 dBi within the operational broad bandwidth.

Sustained Acoustic Medicine Combined with A Diclofenac Ultrasound Coupling Patch for the Rapid Symptomatic Relief of Knee Osteoarthritis: Multi-Site Clinical Efficacy Study.

Background:Sustained Acoustic Medicine (SAM) is an emerging, non-invasive, non-narcotic, home-use ultrasound therapy for the daily treatment of joint pain. The aim of this multi-site clinical study was to examine the efficacy of long-duration continuous ultrasound combined with a 1% diclofenac ultrasound gel patch in treating pain and improving function in patients with knee osteoarthritis.Methods:The Consolidated Standards of Reporting Trials (CONSORT) were followed. Thirty-two (32) patients (18-males, 14-females) 54 years of average age with moderate to severe knee pain and radiographically confirmed knee osteoarthritis (Kellgren-Lawrence (KL) grade II/III) were enrolled for treatment with the SAM device and diclofenac patch applied daily to the treated knee. SAM ultrasound (3 MHz, 0.132 W/cm2, 1.3 W) and 6 grams of 1% diclofenac were applied with a wearable device for 4 hours daily for 1 week, delivering 18,720 Joules of ultrasound energy per treatment. The primary outcome was the daily change in pain intensity using a numeric rating scale (NRS 0–10), which was assessed prior to intervention (baseline, day 1), before and after each daily treatment, and after 1 week of daily treatment (day 7). Rapid responders were classified as those patients exhibiting greater than a 1-point reduction in pain following the first treatment. Change in Western Ontario McMaster Osteoarthritis Questionnaire (WOMAC) score from baseline to day 7 was the secondary functional outcome measure. Additionally, a series of daily usability and user experience questions related to devising ease of use, functionality, safety, and effectiveness, were collected. Data were analyzed using t-tests and repeated measure ANOVAs.Results:The study had a 94% retention rate, and there were no adverse events or study-related complaints across 224 unique treatment sessions. Rapid responders included 75% of the study population. Patients exhibited a significant mean NRS pain reduction over the 7-day study of 2.06-points (50%) for all subjects (n=32, p<0.001) and 2.96-points (70%) for rapid responders (n=24, p<0.001). The WOMAC functional score significantly improved by 351 points for all subjects (n=32, p<0.001), and 510 points for rapid responders (n=24, p<0.001). Over 95% of patients found the device safe, effective and easy to use, and would continue treatment for their knee OA symptoms.Conclusion:Sustained Acoustic Medicine combined with 1% topical diclofenac rapidly reduced pain and improved function in patients with moderate to severe osteoarthritis-related knee pain. The clinical findings suggest that this treatment approach may be used as a conservative, non-invasive treatment option for patients with knee osteoarthritis. Additional research is warranted on non-weight bearing joints of the musculoskeletal system as well as different topical drugs that could benefit from improved localized delivery.Clinical Trial Registry Number: (NCT04391842).

Design of broadband circularly polarized metasurface antenna array with gain enhancement

In this paper, a broadband right-hand-circular polarization metasurface antenna array is designed to satisfy the specific satellite-based installation platform. The slot coupling patch antenna is employed as element to construct the 4 × 4 array and narrow beam can be obtained by this way. The gain and performance of the antenna array are improved by adding the metasurface parasitic patch patches. By employing the H-shape slot coupling feed structure arranged in T-shape and broadband 90° phase shifter, the antenna can achieve the broadband circularly polarized characteristics. And by utilizing Wilkinson power divider, broad impedance bandwidth can be obtained. The simulated results indicate that the S11 of the antenna array is below 10 dB in the operating band from 6.4 to 13.9 GHz (73.9%), the AR bandwidth is from 7 to 13.3 GHz (62.1%). And the gain is more than 15.4 dB in the X-band with the peak gain 19.7dBi at 11.3 GHz. The antenna array is fabricated to validate the design. The measured results and simulated results agree well, broadband bandwidth, circularly polarized, narrow beam, and low profile are achieved. The operating band of the array covers the whole X-band which is suitable for the actual satellite-based antenna applications.

A low‐profile dual‐band shared‐aperture antenna based on artificial magnetic conductor with transparent elements

AbstractThis article presents a dual‐band shared‐aperture antenna. The lower‐band antenna consists of two printed dipoles operated in a 1.6‐2.4 GHz frequency band. An artificial magnetic conductor (AMC) is used to reduce the lower‐band antenna profile. The higher‐band antenna consists of 4 × 2 aperture coupling patches operated in 5.3‐7.1 GHz frequency band and placed between the antenna ground plane and the AMC. The AMC elements act as a bandpass frequency‐selective surface for the higher‐band antenna. Simulated and measured results show that the proposed antenna has 40% and 29% impedance and 3‐dB gain bandwidths for the lower‐band and higher‐band antennas, respectively, and port isolation of less than −20 dB.

Ultralow Profile, Low Passive Intermodulation, and Super-Wideband Ceiling Mount Antennas for Cellular and Public Safety Distributed Antenna Systems.

This paper presents an ultralow profile, low passive intermodulation (PIM), and super-wideband in-building ceiling mount antenna that covers both the cellular and public safety ultra high frequency (UHF) band for distributed antenna system (DAS) applications. The proposed antenna design utilizes a modified 2-D planar discone design concept that is miniaturized to fit into a small disc-shaped radome. The 2-D planar discone has an elliptical-shaped disc monopole and a bell-shaped ground plane, a stub at the shorting path, with asymmetrical structure and an additional proximity coupling patch to maximize the available electrical path to support the 350 MHz band range. The proposed design maximizes the radome area with a reduction of about 62% compared to similar concept type antennas. Besides, the proposed design exhibits an improved radiation pattern with null reduction compared to a typical dipole/monopole when lies at the horizontal plane. A prototype was manufactured to demonstrate the antenna performance. The VSWR and radiation pattern results agreed with the simulated results. The proposed antenna achieves a band ratio of 28.57:1 while covering a frequency range of 350–10000 MHz. The measured passive intermodulation levels are better than −150 dBc (2 × 20 Watts) for 350, 700 and 1920 MHz bands.