Coplanar Waveguide Technique Research Articles

A Compact and Flexible Monopole Antenna with Controllable Bandwidth

In this paper, a compact antenna with flexible and controllable bandwidth characteristics is proposed. To ensure wide coverage along with an omnidirectional radiation pattern, a monopole structure was utilized as the primary radiating element of the proposed antenna. The monopole was fed using a coplanar waveguide technique to achieve a single-layer design. To alter the operating bandwidth, defined by a reflection coefficient of less than -10 dB, a single stub was directly connected to the feeding transmission line. By controlling the stub's length, matching performance in the high-frequency range was found to undergo significant degradation, indicating that the operating bandwidth could be controlled. Furthermore, for validation, two antenna prototypes were fabricated and measured under different circumstances. In the unbending mode, the design without the stub achieved a wideband of 51.6%, while the other design with the stub exhibited a narrower band of about 19.6%. Additionally, the antennas worked efficiently when operating in bending mode. It is also worth noting that the antenna gain and radiation pattern remained stable across the entire operating bandwidth.

A novel miniaturized V-shaped monopole antenna for GSM/WiMAX/WLAN applications

Abstract This paper presents a novel miniaturized triple band V-shaped antenna (VSA). The miniaturization and the triple-band operation are obtained by performing two V-shaped turns on the metallic strip. The proposed antenna is printed on a single FR4 substrate and fed using the coplanar waveguide (CPW) technique. It operates in three frequency bands, [1.6–1.95 GHz], [2.8–4.4 GHz] and [5.4–5.8 GHz], with stable bidirectional radiation patterns in both E- and H-planes. A prototype of the designed antenna is fabricated and tested where the observed good agreement between simulated and experimental results indicates that the proposed structure, having a reasonably compact size of 0 . 0166 λ 0 2 $\text{0}{\text{.}0166\lambda }_{0}^{2}$ , is suitable for GSM [1800 MHz], WiMAX [3.4–3.77 GHz] and WLAN [5.725–5.825 GHz] applications.

A wideband circularly polarized CPW-fed substrate integrated waveguide based antenna array for ISM band applications

This article presents a compact size circularly polarized substrate integrated waveguide (SIW) based wideband antenna array that serves industrial, scientific, and medical (ISM) band applications. A coplanar waveguide (CPW) technique is used to ensure the antenna size compactness. The proposed antenna is fabricated on a low-profile Rogers RT6002 substrate with a dielectric constant of 2.94, tanδ of 0.0012 and an approximate height of 0.76mm. The proposed design covers the frequency range from 2.15 GHz to 3.63 GHz (60.4%) while the axial ratio has a 3 dB bandwidth covering from 2.19 GHz to 2.51 GHz (13%) at the operating band of 2.45 GHz. The antenna is miniaturized and has a size of about 46.50 × 29 × 0.76 mm3. The simulation and experimental results are taken into consideration and there is a good promise between them. Hence, the antenna is a suitable applicant to be utilized for the applications in the ISM band.

High Gain Compact UWB Antenna for Ground Penetrating Radar Detection and Soil Inspection.

An ultrawide bandwidth (UWB) antenna for ground-penetrating radar (GPR) applications is designed to check soil moisture and provide good-quality images of metallic targets hidden in the soil. GPR is a promising technology for detecting and identifying buried objects, such as landmines, and investigating soil in terms of moisture content and contamination. A paddle-shaped microstrip antenna is created by cutting a rectangular patch at one of its diametrical edges fed by the coplanar waveguide technique. The antenna is loaded by stubs, shorting pins, and a split-ring resonator (SRR) metamaterial structure to increase the antenna’s gain and enhance the bandwidth (BW) towards both the lower and higher end of the working BW. The antenna’s performance in soil inspection is studied in terms of the operating frequency range, different types of soil, different distances (e.g., 50 cm) between the antenna arrays and soil, S-parameters, and gain. Following this, the antenna’s ability to find a metallic target in the soil is tested, considering different array numbers, multi-targets, and locations. The antenna is designed on a thin layer of economic polytetrafluoroethylene (PTFE) substrate with dimensions 50 × 39 × 0.508 mm3 and works in the frequency range 1.9–9.2 GHz. In addition, two more resonances at 0.9 and 1.8 GHz are also achieved; hence, the antenna works for more than two application bands, such as the ISM- and L-bands. The measurement results validated excellent agreement with the simulated results. Furthermore, the recommended antenna offering a high gain of about 10.8 dBi and maximum efficiency above 97% proved able to discriminate between hidden objects and even recognize their shapes. Moreover, the reconstructed images show that the antenna can detect an object in the soil at any location.

Design and development of a graphene-based reconfigurable patch antenna array for THz applications

Abstract This paper presents a graphene-based antenna array for terahertz (THz) applications. The suggested antenna array has four radiating square shaped patches fed by a coplanar waveguide (CPW) technique. The proposed antenna array operates at the three frequencies with operational bandwidths of 1.173–1.210 THz (at 1.19 THz), 1.270–1.320 THz (at 1.3 GHz), and 1.368–1.346 THz (at 1.4 GHz). The total area of the antenna array is reported as 1000 × 1000 µm2, printed on a Silicon substrate with a thickness of 20 µm and a dielectric constant of ϵ r = 11.9. To enhance the structure’s performance and optimize the feeding network, a parametric analysis was performed using the FDTD technique. Furthermore, the key properties of the proposed antenna array, such as resonance frequency, peak gain, and radiation efficiency, may be changed by adjusting the chemical potentials of the graphene in the antenna array. The use of graphene’s chemical potential tuneability yields exceptional results comparing to the recent research outputs, with a peak gain and radiation efficiency of 10.45 dB and 70%, respectively. These results show the performance of the suggested design for constructing antenna arrays for use in THz applications.

A Jug-Shaped CPW-Fed Ultra-Wideband Printed Monopole Antenna for Wireless Communications Networks

A type of telecommunication technology called an ultra-wideband (UWB) is used to provide a typical solution for short-range wireless communication due to large bandwidth and low power consumption in transmission and reception. Printed monopole antennas are considered as a preferred platform for implementing this technology because of its alluring characteristics such as light weight, low cost, ease of fabrication, integration capability with other systems, etc. Therefore, a compact-sized ultra-wideband (UWB) printed monopole antenna with improved gain and efficiency is presented in this article. Computer simulation technology microwave studio (CSTMWS) software is used to build and analyze the proposed antenna design technique. This broadband printed monopole antenna contains a jug-shaped radiator fed by a coplanar waveguide (CPW) technique. The designed UWB antenna is fabricated on a low-cost FR-4 substrate with relative permittivity of 4.3, loss tangent of 0.025, and a standard height of 1.6 mm, sized at 25 mm × 22 mm × 1.6 mm, suitable for wireless communication system. The designed UWB antenna works with maximum gain (peak gain of 4.1 dB) across the whole UWB spectrum of 3–11 GHz. The results are simulated, measured, and debated in detail. Different parametric studies based on numerical simulations are involved to arrive at the optimal design through monitoring the effects of adding cuts on the performance of the proposed antennas. Therefore, these parametric studies are optimized to achieve maximum antenna bandwidth with relatively best gain. The proposed patch antenna shape is like a jug with a handle that offers greater bandwidth, good gain, higher efficiency, and compact size.

A Compact CPW-Fed Ultra-Wideband Multi-Input-Multi-Output (MIMO) Antenna for Wireless Communication Networks

In this article, a compact coplanar waveguide (CPW) technique based ultra-wideband multiple-input-multiple-output (MIMO) antenna is proposed. The design is characterized by a broad impedance bandwidth starting from 3 GHz to 11 GHz. The overall size of the MIMO design is <inline-formula> <tex-math notation="LaTeX">$60\times60$ </tex-math></inline-formula> mm² (<inline-formula> <tex-math notation="LaTeX">$1.24\times 1.24\,\,\lambda _{g}^{2}$ </tex-math></inline-formula> &#x0040; 3 GHz) with a thickness of 1.6 mm. To make the design ultra-wideband, the proposed MIMO antenna design has four jug-shaped radiating elements. The design is printed on a FR-4 substrate (relative permittivity of <inline-formula> <tex-math notation="LaTeX">$\varepsilon _{r} = 4.4$ </tex-math></inline-formula> and loss tangent of <inline-formula> <tex-math notation="LaTeX">$\mathrm {tan}\delta = 0.025$ </tex-math></inline-formula>). The polarization diversity phenomenon is realized by placing four antenna elements orthogonally. This arrangement increases the isolation among the MIMO antenna elements. The simulated results of the ultra-wideband MIMO antenna are verified by measured results. The proposed MIMO antenna has a measured diversity gain greater than 9.98, envelope correlation coefficient (ECC) less than 0.02, and good MIMO performance where the isolation is more than &#x2212;20dB between the elements. The group delay, channel capacity loss (CCL), and the total active reflection coefficient (TARC) multiplexing efficiency and mean effective gain results are also analyzed. The group delay is found to be less than 1.2ns, CCL values calculated to be less than 0.4 bits/sec/Hz, while the TARC is below &#x2212;10dB for the whole operating spectrum. The proposed design is a perfect candidate for ultra-wideband wireless communication systems and portable devices.

Stair-Hexagonal Slot Antenna with Coplanar Waveguide Technique for Biomedical Applications

Breast cancer is the most common disease suffered by women and increases significantly. Ultra-Wideband (UWB) is a technology that applies electromagnetic signals with wide bandwidth that are currently widely used in the medical field. This research introduces the design of the Stair-Hexagonal slot antenna with the Coplanar Waveguide (CPW) technique which operated at desired frequency of 5.8 GHz. Firstly, the design process of the antenna is adding stair slot to get wide bandwidth. Secondly by adding Hexagonal slot to get the best S11 parameter at the desired frequency. The purpose of antenna is to detect an object in body organs such as tumors and cancer. The antenna is printed and tested. The measured return loss shows that the antenna works well in the desired frequency with wider bandwidth than simulated one. The measured bandwidth of 7.88 GHz is achieved. The gain of the antenna from the simulation is 2.42 dBi and radiation pattern of simulation and measurement are bidirectional, wherein the highest gain is in the rear position. Further analysis is done by comparing the proposed antenna with the existing related works. The result of this research shows the practical usage of the flexible substrate because it can increase the accuracy of object detection.

A low cost fractal CPW fed antenna for UWB applications with a circular radiating patch

In this study a validated antenna into simulation and through measurement has been described and analyzed. The coplanar waveguide (CPW) technique has been chosen to feed the radiating patch while the two ground planes have been partially designed in the top side of the substrate. The fractal geometry, applied to the circular radiator, has been obtained by merging the circular and rectangular shapes. The fiberglass FR-4, with a single side of 35μm copper thickness, has been used to achieve the antenna material with a permittivity of 4.4, a thickness of 1.6 mm, a loss tangent of 0.025 and an overall dimension of 34x43 mm 2 . The proposed CPW fractal antenna has been configured to operate in the frequency range 3.1-10.6 GHz published by the federal communications commission (FCC) as an ultra-wide band (UWB). To calculate the return loss, the gain, the current density and the radiation pattern of the simulated antenna, two electromagnetic solvers have been involved which are the CST microwave studio and ADS. The series of measurement have been performed by using the network analyzer and the anechoic chamber in order to confirm the computed antenna.

A CPW-fed flexible UWB antenna for IoT applications

In order to keep pace with the growing research and development on flexible and reconfigurable electronics, this research presents an inkjet printed ultra-wideband (UWB) flexible antenna on photo paper. The antenna pattern comprises a circular patch with the double stepped symmetric ground plane and is fed by a coplanar waveguide (CPW) technique on one-sided photo paper. The system is designed, simulated, fabricated, and tested experimentally. It operates over 3.2–30 GHz (161% fractional bandwidth, FBW) range with a return loss of − 10 dB or less and a voltage standing wave ratio (VSWR) < 2. The proposed monopole antenna is of dimensions 33.1 mm × 32.7 mm × 0.254 mm with an electrical size of 0.35 λ × 0.35 λ at 3.2 GHz frequency. This design exhibits nearly omnidirectional radiation pattern over the entire impedance bandwidth. An average gain of 4.87 and a radiation efficiency of 86.61% was observed. The miniature size, higher operating range, relatively constant radiation pattern along with higher acceptable peak gain of the antenna on a paper substrate lend itself to wearable and Internet of Things (IoT) applications.

Symmetrical Couple F-Shaped Notches with High Rejection C-Band of UWB Patch Antenna

The ultra-wideband (UWB) antenna is developed to cover a broad bandwidth. ‎The UWB radio systems are interfered ‎by the ‎same ‎spectrum ‎that shared with the local bands. In this paper, two F-shaped slots on a hexagonal patch UWB antenna are demonstrated ‎‎ to realize a high band rejection. The symmetrical couple F-slots is ‎notched on the hexagonal UWB ‎ ‎patch antenna to avoid the interference ‎and ‎‎enhance the notching results at C-band. The demonstrated ‎antenna employs a coplanar waveguide ‎(CPW) technique to meet a fractional bandwidth of 126%. The proposed method validates ‎several ‎‎reconfigurations of the F-slot location on the demonstrated design. Six steps ‎parametric study are considered to test the slots location. The results of the proposed antenna with slots are introduced based on analytical, simulation, and ‎measurement. The total design size ‎‎28 mm × 43 mm × 1.6 ‎mm is simulated by ‎using CST Microwave Studio. The two F-slots are achieved the antenna gain of -6 dB, ‎return loss of -1.2 ‎dB, and ‎VSWR of 15.2 at the rejected band of 4 GHz. The ‎measurement results are compared with the simulation results between the three ‎prototypes. The current ‎distribution on the design is discussed at 2.88 GHz and 4 GHz frequencies. The radiation patterns illustrate ‎omnidirectional of H-plane and bidirectional of E-plane. This paper validates the slots locations to enhance the notches performance and reduce the interference.

Proximity Ring Fed Multiband Printed Monopole Fractal Antenna

Small antennas satisfying bandwidth requirements in wideband, broadband and multichannel communication systems are of wide interest among researchers. This paper investigates the resonant behaviour of proximity coupled circular fractal planar monopole against circular fractal planar monopole without proximity coupling. The antennas are fed using microstripline and coplanar waveguide technique.

Proximity Ring Fed Multiband Printed Monopole Fractal Antenna

Small antennas satisfying bandwidth requirements in wideband, broadband and multichannel communication systems are of wide interest among researchers. This paper investigates the resonant behaviour of proximity coupled circular fractal planar monopole against circular fractal planar monopole without proximity coupling. The antennas are fed using microstripline and coplanar waveguide technique. These antennas are designed and printed on low cost FR4 substrate ( height h=1.56mm and er =4.3) of size 110 mm by 115 mm with circular patch radius of 40 mm. The planar fractal monopole shows multiband characteristics under different configurations of feed. The monopole can be used for various compact applications in 482 MHz to 4 GHz band.

Rounded bevel shaped fed cylindrical dielectric resonator antenna for wideband applications

ABSTRACTA cylindrical dielectric resonator antenna fed by a rounded bevel shaped patch has been proposed in this letter. The antenna structure uses coplanar waveguide technique with truncated ground plane. The cylindrical dielectric resonator (DR) loads the patch at low frequencies and also adds its own resonances to obtain a wideband performance. The proposed antenna structure achieves a measured impedance bandwidth of 124.4% covering frequency range from 4.4 to 18.9 GHz. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2364–2368, 2015

Bandwidth enhancement metamaterial antenna based on transmission line approach

ABSTRACTA composite right‐/left‐handed transmission line metamaterial antenna with enhanced bandwidth and efficiency is proposed. The antenna combines zeroth‐order resonant (ZOR) and positive‐order resonant (POR) modes for the bandwidth enhancement. An asymmetrical coplanar waveguide technique is used to feed the antenna and also to achieve certain degree of compactness. The overall size of the antenna is 0.32λ0 × 0.38λ0 × 0.012λ0 (40 × 48 × 1.52 mm) at 2.4 GHz. Simulation results show that a bandwidth enhancement of 41% is obtained with the radiation efficiencies of 95 and 97% for the ZOR and POR modes, respectively. The measured impedance bandwidth shows that the antenna has potential applications for WLAN (2.39–2.45 GHz) and WiMAX (2.5–2.69 GHz) operations. The simulated and measured antenna performances in terms of return loss and the radiation patterns are presented and compared. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:252–256, 2015

Dual mode metamaterial antenna for wideband applications

A dual mode metamaterial antenna is proposed. The antenna is a monopole loaded with metamaterial (MTM) unit cell. An asymmetrical coplanar waveguide (ACPW) technique is employed to achieve a certain degree of compactness. The overall size of the antenna is 0.32λ0 × 0.21λ0 (39 × 25 mm2) at 2.5 GHz. The bandwidth enhancement is achieved when zeroth-order resonance (ZOR) mode is merged to the positive order resonance (POR) mode. Simulated results show that a bandwidth enhancement of 39% is obtained with the radiation efficiencies of 75% and 91% for the ZOR and POR modes, respectively. The return loss response shows that the designed antenna is matched and able to work well within a frequency range of 2.4567–3.6008 GHz, which is suitable for WiMAX applications (2.5–2.69 GHz/3.3–3.365 GHz). The simulated and measured antenna performances in terms of return loss and the radiation patterns are presented and compared. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1846–1850, 2014

A W-band two-stage cascode amplifier with gain of 25.7 dB

A W-band two-stage amplifier MMIC has been developed using a fully passivated 2 × 20 μm gate-width and 0.15 μm gate-length InP-based high electron mobility transistor (HEMT) technology. The two-stage amplifier has been realized in combination with a coplanar waveguide technique and cascode topology, thus leading to a compact chip-size of 1.85 × 0.932 mm2 and an excellent small-signal gain of 25.7 dB at 106 GHz. Additionally, an inter-digital coupling capacitor blocks low-frequency signal, thereby enhancing the stability of the amplifier. The successful design of the two-stage amplifier MMIC indicates that InP HEMT technology has a great potential for W-band applications.

Broadband magneto-dielectric response of particulate ferrite polymer composite at microwave frequencies

Complex permittivity and permeability of a magneto-dielectric composite material is studied using shielded, conductor-backed coplanar waveguide technique over X-band. The propagation constant over the test frequency range is evaluated using element-to-element correspondence of the ABCD matrix computed from scalar scattering parameters without modifying the coplanar structure. The mathematical formulation is verified by performing permittivity and permeability measurements for air over the range 9.5–12.045GHz. Nano-sized nickel ferrite particles was synthesized using co-precipitation technique at different sintering temperatures. Average crystallite diameter is found to be 6.63–17.55nm. The composite with 2% and 4% volume fractions is fabricated by reinforcing 6.63nm ferrite particles in low density polyethylene matrix. The complex permittivity and permeability of the composite obtained from this method are also verified with cavity perturbation technique. The composite shows low saturation magnetization of 1.8745emu/g and reduced hysteresis loss at room temperature.

Metamaterial CRLH Antennas on Silicon Substrate for Millimeter-Wave Integrated Circuits

The paper presents two composite right/left-handed (CRLH) coplanar waveguide (CPW) zeroth-order resonant (ZOR) antennas which were designed, processed, and electrically characterized for applications in the millimetric wave frequency range. Two CRLH antennas were developed forf=27 GHz andf=38.5, GHz, respectively. The CRLH antenna onf=27 GHz shows a return loss ofRL&lt;−18.78 dB atf=26.88 GHz. The −3 dB radiation characteristic beamwidth was approximately 37° and the gain wasGi=2.82 dBi. The CRLH antenna onf=38.5 GHz has a return loss ofRL&lt;−38.5 dB atf=38.82 GHz and the −3 dB radiation characteristic beamwidth of approximately 17°. The gains wereGi=1.08 dBi atf=38 GHz andGi=1.2 dBi atf=38.6 GHz. The maximum measured gain wasGi=1.75 dBi atf=38.2 GHz. It is, upon the authors' knowledge, the first report of millimeter wave CRLH antennas on silicon substrate in CPW technique for use in mm-wave monolithic integrated circuit.

A 52-GHz 8.5-dB Traveling-Wave Amplifier in 0.13-$\mu$m Standard CMOS Process

The design of a traveling-wave amplifier (TWA) in 0.13-mum standard CMOS technology is presented. It is designed to maximize the gain-bandwidth product (GBP). An asymmetric cascode, coplanar waveguide (CPW), and loss compensation technique enables maximization of the TWA GBP. Design and modeling of 90-Omega CPW used to synthesize inductors of the TWA lines is presented. Simulations with a design kit and developed models for CPW show a 52-GHz bandwidth with a maximum power gain of 8.5 dB at 10 GHz for a 135-mW power consumption. Measurements up to 40 GHz confirm these results.