Coplanar Antenna Research Articles

High-performance 5.5 THz coplanar waveguide-fed circular dielectric resonator antenna: a dual-band solution for advanced THz applications

High-performance 5.5 THz coplanar waveguide-fed circular dielectric resonator antenna: a dual-band solution for advanced THz applications

Triple notched coplanar waveguide-fed novel ultrawide band antenna with time domain analysis

This research proposition introduces a novel microstrip antenna design that features triple notches for ultra-wideband (UWB) applications. The antenna, measuring 35.4 mm × 28.82 mm × 1.57 mm, incorporates rectangular and semi-circular slots, as well as a pentagonal stub. A modified U-shaped slot on the pentagonal stub creates one notched frequency band at 3.3–3.7 GHz. Additionally, two Split Ring Resonators (SRRs) are integrated into the antenna’s rear surface, resulting in two more notched bands at 5.1–5.8 GHz and 7.1–7.8 GHz. Operating within a frequency range from 3 to 11.2 GHz with VSWR ≤ 2, the antenna effectively excludes the triple stop bands at 3.3–3.7 GHz (11.4%), 5.1–5.8 GHz (12.8%) and 7.1–7.8 GHz (9.4%). The proposed antenna has been successfully prototyped and verified. An extensive result analysis has been conducted, confirming that the developed antenna is suitable for application in a range of wireless systems. Moreover, the article includes the implementation of an equivalent circuit for the proposed antenna.

A flexible wideband wearable CPW antenna for WBAN application

Abstract This article presents a wideband wearable antenna with flexible substrate for Body Area Network application. The designed coplanar antenna has a return loss bandwidth of 3.5 GHz ranging from 5.15 GHz to 8.65 GHz with maximum return loss at 5.8 GHz (45.9 dB) and 7.4 GHz (31.4 dB). The average gain of the antenna is 4.069 dB. The obtained specific absorption rate of the antenna is below the FCC reference limit of 1.6 W/Kg per 1 g of tissue, making it suitable for biomedical application.

A novel moon-shaped flexible four-element co-planar antenna for 5G applications

A novel moon-shaped flexible four-element co-planar antenna for 5G applications

Investigation of Mode-Induced Spin Wave Transmission Blockage by In Situ Nanoscale Grooves.

In the pursuit of advancing spin-wave optics, the propagation of magnetostatic surface spin-waves is investigated in a uniform permalloy waveguide with in-situ nanopatterned grooves created through Atomic Force Microscopy nanolithography and Focused Ion Beam etching. The study unveils that the introduction of narrow constrictions and grooves leads to a non-monotonic reduction of the transmitted spin-wave signal intensity as the spin-wave pathway is shrinked. The remarkable feature that a stronger signal extinction is obtained for a narrow groove compared to a spin-waveguide interrupted by a full gap, where only inefficient transport through dipolar coupling is allowed, is highlighted. Combining experimental and numerical analyses, the intricate interplay between spin-wave diffraction and reflection at the waveguide edges is unraveled, being at the origin of a transverse-mode variation responsible for the signal extinction when detected using coplanar antennas. The findings offer insights into the controllable manipulation of detected spin-wave intensity, thereby opening promising avenues for the improvement of spin-wave switches and interferometers, and for the nanopatterning of graded indexmagnonics.

Optically transparent coplanar wideband antenna for vehicular communication

SummaryThe presented state of the art is a novel coplanar optically transparent antenna designed to operate in extended GSM, L‐band, and UWB applications for vehicular communication. The presented radiator operates using a coplanar waveguide feed mechanism without a separate ground plane layer with a minimal conductive surface to enhance the transparency of the proposed antenna. The proposed antenna design has dimensions of 40 × 20 mm2, and a transparent material of soda–lime glass is used as a substrate with a dielectric constant of 7. The radiating element over the substrate is the conductive film fluorine‐doped tin oxide (FTO) with a sheet resistance of 7 Ω/sq. The operating frequency range of the designed antenna is from 0.86 to 14.45 GHz, which encloses the E‐GSM (900 MHz), L‐band (1–2 GHz), and UWB (3.1–10.6 GHz) frequencies. The peak gains at the operating frequencies are 1, 1.6, and 4.34 dBi, respectively. The designed antenna is fabricated and measured, and the performance metrics are plotted and compared. Since the transparent antenna is designed, the tendency of a substance to conduct light is measured as the optical transmittance, and it is calculated as 95% in the glass reference and 82% in the air reference.

Wideband shared-aperture orthogonal mode antenna pair for MIMO application

A wideband shared-aperture antenna is designed for MIMO application based on asymmetric orthogonal-mode antenna pair. A symmetric T-shaped antenna and an asymmetric double-L-shaped antenna constitute the proposed antenna pair. Two co-planar antenna elements are configured above the ground (on the same substrate side). The wideband self-decoupling characteristic of the antenna pair is achieved via orthogonal modes. The proposed shared-aperture antenna demonstrates good impedance matching, high isolation, and good diversity performance over a bandwidth of 3.04–5.28 GHz, covering the 5G N77/N78/N79 bands, which is suitable for compact 5G MIMO terminals. Two such antenna pairs are arranged along the upper side of the ground to construct a 4-port MIMO antenna. The proposed MIMO antenna is fabricated and tested to verify its performance. Favorable results are realized, including impedance matching, isolation, efficiency, and ECC. The measured results are in good agreement with the simulated results.

A Novel Dual-Band Circularly Polarized Wearable Antenna.

A circularly polarized wearable antenna operating in the 2.45/5.8 GHz ISM dual bands is proposed, which consists of a coplanar waveguide-fed rectangular monopole antenna and two parasitic branches. The monopole rectangular radiation patch can generate 2.45 and 7 GHz frequency bands and has linear polarization characteristics. By adding L-shaped parasitic branches and L-like grounded branches on both sides of the monopole, the 7 GHz operating frequency band can be moved to the 5.8 GHz frequency band, and circular polarization characteristics can be achieved in both the 2.45 and 5.8 GHz frequency bands. The size of the antenna is 48.7 mm × 42.1 mm × 1.016 mm. The simulated -10 dB impedance bandwidths of the antenna are 1.8-2.66 GHz and 5.48-6.98 GHz, respectively. The 3 dB axial ratio bandwidths are 2.34-2.67 GHz and 5.58-6.39 GHz, respectively, and it has dual-band circular polarization characteristics. In addition, the radiation characteristics of the antenna and its safety performance near the human body were analyzed. The antenna prototype has been constructed, and the measurement and simulation results have good consistency. The proposed antenna is suitable for application in wearable devices.

Microwave magnonic micro-oscillator based on a nm-thick YIG film

A numerical model describing a magnonic active ring oscillator (MARO) based on a microscopic spin-wave delay line is proposed. The model considers excitation, propagation, and reception of the magnetostatic surface waves in a yttrium iron garnet (YIG) magnetic film with a thickness in the nanometer range. The waves are excited and received with a microscopic coplanar antenna. We employed the model to analyze the influence of the YIG-film thickness and the distance between the antennas on the MARO performance characteristics. We showed that an increase in the delay time inserted by the delay line reduces the phase noise of the MARO and increases the auto-oscillation threshold. In addition, we found a relation between the auto-oscillation threshold, the thickness of the YIG film, and the distance between the antennas. The relation helps design miniature MAROs and suggests a way to reduce the phase noise of the device. The model predicts a phase noise level of −115 dBc/Hz at a 10 kHz offset from an oscillation frequency in the vicinity of 5 GHz for the MARO based on a 100 nm-thick YIG film and 56 μm of distance between the coplanar nano-antennas of the YIG-film based delay line. We believe that this is a clear way forward to microminiaturize the time-delay feedback microwave auto-oscillators. A further reduction in the phase noise down to −125 dBc/Hz at a 10 kHz offset is found in a model of cascaded connection of several microscopic spin-wave delay lines.

Airborne Short-Baseline Millimeter Wave InSAR System Analysis and Experimental Results

For the challenges of high-precision mapping in complex terrain, a novel airborne Interferometric Synthetic Aperture Radar (InSAR) system is designed. This system, named ASMIS (Airborne Short-Baseline Millimeter-Wave InSAR System), adopts the coplanar antenna and a pod-type structure. This design makes the system lightweight and highly integrated. It can be compatible with small general aviation flight platforms. The baseline is millimeters in size, which greatly simplifies the unwrapping process. The coplanar antennas have two advantages: they maximize the baseline utilization and minimize the Doppler decorrelation and the motion error inconsistency. Acquisition campaigns of the system have been carried out in Boao, Bayannur, and Chengde, China. In the Chengde experimental area, we designed an antiparallel flight experiment to account for the topographic relief. High-precision Digital Orthophoto Maps (DOMs) and Digital Surface Models (DSMs) at a scale of 1:5000 were obtained. The coordinate Root Mean Square Error (RMSE) of the checkpoints within the obtained DSM is less than 0.82 m in altitude and 3 m horizontally. The RMSE of the Sparse Ground Control Points (GCPs) within the obtained DSM is less than 0.3 m in altitude. Experimental results from different areas, including plains, mountains, and coastlines, demonstrate the system’s performance.

The effect of thickness of a conductive nanocomposite ink printed on textile co-planar waveguide antenna

The effect of thickness of a conductive nanocomposite ink printed on textile co-planar waveguide antenna

Screen‐printed dual‐band wearable textile antenna incorporated with EBG structure for WBAN communications

SummaryA dual‐band, wearable coplanar microstrip patch antenna (CPW) integrated with electromagnetic bandgap structure (EBG) to operate dual wireless bands at 2.48 GHz industrial, scientific, and medical band (ISM) and 5.2 GHz WLAN. The proposed textile wearable antenna and EBG structure are screen‐printed using silver conductive ink on the cotton polyester substrate (εr = 1.6) for flexible wearable applications. A 3 × 3 EBG array is realized by a concentric square patch surrounded by the annular square ring to reduce back radiation and increase the forward gain and front‐back ratio. The proposed EBG‐backed antenna, compared with the conventional CPW‐fed antenna, improves forward gain from 2.18 to 6.59 dB at 2.48 GHz and 3.5 to 7.03 dB at 5.2 GHz. Moreover, the EBG array is used to isolate the human body from the antenna and reduces the specific absorption rate (SAR). The antenna is performed with a human phantom tissue model, which exhibits a specific absorption rate of 0.12 W/kg, and 0.260 W/kg for 1 g tissue at 2.48 GHz and 5.2 GHz, respectively.

A Co-Planar Waveguide Ultra-Wideband Antenna for Ambient Wi-Fi RF Power Transmission and Energy Harvesting Applications

This study proposes an ultra-wideband antenna for ambient radio frequency (RF) energy harvesting applications. The antenna is based on a co-planar waveguide (CPW) transmission line and incorporates a rectangular slot as an antenna harvester. The proposed antenna utilizes an evolutionary design process to achieve impedance matching of the 50 Ω CPW feeding line over the desired frequency bands. A parametric study investigates CPW elements and rectangular slot size. The harvester antenna is then connected to the primary rectifier circuit of the voltage doubler to examine the signal characteristics. The antenna covers the Industry, Science, and Medicine (ISM) Wi-Fi bands of 2.45 GHz and 5 GHz, achieving a realized gain of 3.641 dBi and 4.644 dBi at 2.45 GHz and 5 GHz, respectively. It exhibits a relatively broad frequency ranging from 2.16 GHz to 6.32 GHz, covering the ultra-wideband fractional bandwidth (FBW) of 105%.

Unidirectional microwave transduction with chirality selected short-wavelength magnon excitations

Nonreciprocal magnon propagation has recently become a highly potential approach of developing chip-embedded microwave isolators for advanced information processing. However, it is challenging to achieve large nonreciprocity in miniaturized magnetic thin-film devices because of the difficulty of distinguishing propagating surface spin waves along the opposite directions when the film thickness is small. In this work, we experimentally realize unidirectional microwave transduction with sub-micrometer-wavelength propagating magnons in a yttrium iron garnet (YIG) thin-film delay line. We achieve a non-decaying isolation of 30 dB with a broad field-tunable bandpass frequency range up to 14 GHz. The large isolation is due to the selection of chiral magnetostatic surface spin waves with the Oersted field generated from the coplanar waveguide antenna. Increasing the geometry ratio between the antenna width and YIG thickness drastically reduces the nonreciprocity and introduces additional magnon transmission bands. Our results pave the way for on-chip microwave isolation and tunable delay line with short-wavelength magnonic excitations.

Anisotropy evaluation and interface detection based on 3D holographic azimuthal electromagnetic resistivity logging instrument

Abstract 3D holographic azimuthal electromagnetic resistivity logging-while-drilling (LWD) is a convenient and efficient technology to obtain information about formation. It has the advantages of being instant and accurate. It can be applied to fields of engineering such as evaluating anisotropy and detecting nearby geological interfaces. A 3D electromagnetic resistivity azimuthal LWD instrument consists of coaxial, coplanar, tilted and orthogonal antenna systems, being able to solve for all nine components. The explicit generic formulation is derived from presenting the response for a basic unit of one arbitrarily oriented transmitter and one arbitrarily oriented receiver. Combining the responses of basic units with different transmitter-receiver spacing and different components, an ‘anisotropy signal’ is defined with the phase difference ${M}_{px}$ and amplitude ratio ${M}_{ax}$. A ‘boundary signal’ is also defined with the phase difference ${M}_{pz}$ and amplitude ratio ${M}_{az}$. Forward simulation results show that the 2MHz ${M}_{px}$ can accurately identify geological anisotropy in highly deviated and horizontal wells. The ${M}_{az}$ can detect geological interfaces in highly deviated and horizontal wells. the 100 kHz${\rm{\ }}{M}_{az}\ $can detect geological boundaries in the range of 8–9 m.

Highly Integrated In-Band Full-Duplex TRx Antennas for mmWave V2X Communications

A compact mmWave co-circularly polarized (CP) Tx and Rx (TRx) antenna array for in-band full-duplex (IBFDX) V2X communications is proposed. The proposed TRx antenna is based on highly integrated coplanar TRx antenna elements with high Tx-to-Rx isolation maintained in n257 5G NR band. The TRx antenna elements are coplanar patches with the same CP and concentrically integrated to form individual 2 × 2 array on the same substrate. The proposed mmWave IBFDX antenna is designed at 28 GHz with a multilayered printed circuit board (PCB) having sequetially rotated feed networks. Also, the designed antenna is fabricated with the size of 1.867 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 1.867 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.087 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> including both CP feed network and ground plane. The measured 2 × 2 Tx impedance bandwith and peak gain at 28 GHz are 27.14% and 8.43 dBic, respectively. Also, the measured 2 × 2 Rx impedance bandwith and peak gain at 28 GHz are 28.57% and 6.17 dBic, respectively. Further, IBFDX operation of the proposed antenna is verified by n257 5G NR 256-QAM test signals with the maximum 400 MHz bandwidth.

A Highly Transparent Flexible Antenna Based on Liquid Metal Mesh Film

In this paper, a convenient process for the fabrication of flexible liquid metal mesh films (LMMF) is proposed first. Then, the light transmittance and square resistance characteristics of LMMF are studied theoretically and experimentally. The light transmittance of the LMMF can reach 85% when the line width and spacing are 50 μm and 1000 μm, respectively. Furthermore, as an example of LMMF, a coplanar waveguide loop antenna is designed and fabricated that contains an LMMF with a line width of 50 μm and a line spacing of 500 μm. The measured square resistance and transmittance for the LMMF are 0.0456 Ω/sq and 72%, respectively. The measured peak gain of the antenna is 3.38 dBi while the average efficiency is 61%. The antenna’s working frequency covers most of the S-band, C-band, and X-band, as well as multiple channels of fifth generation (5G) communication. Therefore, the antenna can be used in fields such as radar and mobile communication. Uniquely, the fabricated antenna performs well in terms of light transmission, conductivity, and flexibility. In particular, it remains stable in stretching and bending deformation. As a highly light-transmissive stretchable flexible antenna, the antenna is equipped with various functions such as concealability, conformability, and reconfigurability. This LMMF-based antenna has good prospects for applications in the fields of flexible electronics and transparent electronics.

Ring slot CP antenna for the hybrid electromagnetic solar energy harvesting and IoT application

The research proposed a compact antenna integrated with dual-function solar cells to optimize internet of things (IoT) communication devices and energy harvesting. The use of integrated solar cells with electromagnetic elements as antennas and energy-gathering in a design is a solution for wireless communication sensors and simultaneously electromagnetic and solar energy harvesting. Radiation performance testing of solar cell antennas and optical experiments were carried out to test the ability of solar energy collection. A double feed ring slot circular polarization (CP) antenna coplanar antenna with a configuration has highly sensitive to vertical and horizontal waves. It is to accommodate the impact of circular polarization wave and solar cell distortion on antenna performance. This technology promises green communications, renewable energy, and environmental protection to combine wireless communication and green battery components. The study presents the performance and design results of a double line-feed microstrip antenna circuit connected with CP antenna on the S-band for IoT communication by accommodating electromagnetic energy transmission. The importance of adopting an integrated radio frequency (RF) solar energy harvesting strategy rather than a single source method makes this research very significant in its novelty by optimizing the analysis of multiple signal access in IoT communications.

A Compact Size Antenna for Extended UWB with WLAN Notch Band Stub

An ultra-wideband (UWB), geometrically simple, compact, and high-gain antenna with a WLAN notch band is presented for future wireless devices. The antenna is printed on the top side of the Rogers RT/Duroid 5880 substrate and has a small dimension of 10 mm × 15 mm × 0.254 mm. The primary radiator of the proposed coplanar waveguide-fed monopole antenna is comprised of a rectangular-shaped structure initially modified using a slot, and its bandwidth is further enhanced by loading a Y-shaped radiator. As a result, the antenna offers a –10 dB impedance matching bandwidth of 11.55 GHz ranging from 3–14.55 GHz, covering globally allocated C-, S-, and X-band applications. Afterward, another rectangular stub is loaded in the structure to mitigate the WLAN band from the UWB spectrum, and the final antenna offers a notched band spanning from 4.59 to 5.82 GHz. Moreover, to validate the simulated results, a hardware prototype is built and measured, which exhibits good agreement with the simulated results. Furthermore, the proposed work is compared to state-of-the-art antennas for similar applications to demonstrate its design significance, as it has a compact size, wider bandwidth, and stable gain characteristics.

Optically Transparent and Mechanically Flexible Coplanar Waveguide-fed Wideband Antenna Based on Sub-micron Thick Micro-metallic Meshes

Optically Transparent and Mechanically Flexible Coplanar Waveguide-fed Wideband Antenna Based on Sub-micron Thick Micro-metallic Meshes