Compact Coplanar Waveguide Research Articles

A compact coplanar waveguide Wilkinson power divider based on signal traces and adjacent grounds width modulation

AbstractWe propose a miniaturized coplanar waveguide Wilkinson power divider by varying the widths of the signal traces and grounds. Traces are expressed in terms of a truncated Fourier series. Simulated/measured input–output ports matching and isolation are below −15 dB, and the transmission parameters are −3 ± 0.1 dB at the design frequency.

A Coplanar Waveguide Fed UWB Antenna using Embedded E-shaped Structure with WLAN Band-rejection

Abstract A compact coplanar waveguide (CPW)-fed ultra-wideband (UWB) monopole antenna using embedded E-shaped structure with wireless local area network (WLAN) band-rejection is presented. The introduction of this E-shaped structure working as the radiator can enhance the impedance bandwidth of the UWB antenna without increasing the overall size. For preventing the interference from WLAN system, a pair of L-shaped stubs are connected to the ground of UWB antenna to create the rejected band. The center frequency of this rejected band is about 5.5 GHz with the rejection range of 5.2~5.8 GHz. Good agreement can be observed between the simulated and measured results.

Compact CPW-Fed ultrawideband MIMO antenna using hexagonal ring monopole antenna elements

In this paper, a compact coplanar waveguide (CPW) fed ultra-wide band (UWB) multi input multi output (MIMO) antenna is proposed. The antenna consists of two antiparallel hexagonal ring monopole elements. Circular arcs shaped grounded stubs are used to enhance the isolation, both the arcs are connected through stub to make common ground. Tapering of the slots of CPW feed line at feed point, and grounded slots are introduced for impedance matching over UWB. The proposed antenna is fabricated and impedance bandwidth, isolation, radiation pattern, and gain are measured. Moreover, envelop correlation coefficient (ECC) results are given. Proposed antenna structure operates in the frequency range 3–12 GHz with a fractional bandwidth of 120% keeping isolation better than 15 dB. The antenna has a compact size of 45 × 25 mm2.

Compact Unit-Cell-Based Semi-Fractal Antenna with Filtering Properties of Interference Bands Embedded with CBP Strips

ABSTRACTIn this paper, a compact coplanar waveguide (CPW)-fed Ultra Wide Band (UWB) semi-fractal (SF) antenna with dual band filtering characteristics and enhanced bandwidth is presented. The main features of the proposed SF-antenna are the small size of 15 × 15 mm2 dimensions and band-notched characteristics that are obtained without changing the SF radiator. Dual band-notched characteristics are achieved by having a pair of a specific form of shaped strips embedded as conductor back plane (CBP) and defecting CPW ground surface. Also, wider impedance bandwidth can be achieved with this unit-cell-based fractal structure on the radiator. The measured results illustrate that the proposed SF-antenna operates over the VSWR < 2, except two notched bands (3.25–4.32 and 5.02–5.97 GHz), aimed at suppressing any interference from WiMAX IEEE802.16 (3.3–3.6 GHz), C-band (3.7–4.2 GHz), and wireless local area network IEEE802.11a (5.15–5.825 GHz). The SF-antenna has a desirable radiation pattern and gain characteristics for UWB frequency band range. Measured results of the fabricated SF-antenna with the specific form of CBP, unit-cell patterns for radiator and defected CPW ground are presented.

WiMAX and C bands semi-fractal circularly polarized antenna with satellite bands filtering properties

AbstractA compact coplanar waveguide (CPW)-fed circular polarization (CP)-antenna for new generation applications with dual bands filtering performance along with CP feature based on unit-cell semi-fractal is proposed in this paper. The CP-antenna privileges from semi-fractal radiator causes to have a miniaturized size. The stopped bands are designed to suppress the interference with present WLAN and ITU-R satellite systems. These properties are obtained by embedding semi-fractal unit-cell patterns stubs at the radiator and applying two rectangular-shaped slits inside CPW ground plane and a pair of grounded L-shaped strips. By introducing the first step of semi-fractal strips, and the mirrored defected ground surface structures, dual-band rejection functionality at WLAN (5–6 GHz) and ITU-R (7.725–8.5 GHz) are practically obtained. Besides that, semi-fractal strips results to two orthogonal modes stimulation on the radiator and CP attribute are obtained at WiMAX (3.1–3.7 GHz). CP-antenna presents omni-directional radiation H-plane patterns over the applicational frequency band. The CP-antennas size is 25 mm × 25 mm and fabricated on commercially available FR4-epoxy substrate with 1 mm thickness. Measured results illustrate that the proposed ultimate CP-antenna with miniaturized structure, efficient impedance tuning characteristics, and adequate radiation performances is the best choice for new generation of wireless communications.

Design of a CPW fed compact bow‐tie microstrip antenna with versatile frequency tunability

A compact coplanar waveguide (CPW) fed frequency reconfigurable bow-tie microstrip antenna is proposed and experimentally verified which can be tuned at different bands between 1.94 and 3.27 GHz in single-band and dual-band modes. Two slots are carefully introduced on the ground plane of the antenna where two active varactor diodes are placed to vary its fundamental mode of radiation by variation of capacitance. To validate the antenna design, a fully functional prototype is fabricated and measured which ensures that the device can be operated at different frequencies of 2.02, 2.19 and 2.37 GHz with 35.9, 30.8 and 24.6% of impedance bandwidth, respectively, in the single-band mode. In dual-band reconfigurability mode, the resonant frequency of the antenna can be varied at 2.08, 2.17 and 2.3 GHz with a higher mode band within 2.7 and 3.3 GHz. The antenna shows maximum gain of 1.33 dB with 96.9% efficiency and 1.5 dB with 95.4% efficiency for single-band and dual-band reconfigurability mode, respectively. More importantly, the antenna has a compact dimension (0.31λ×0.32λ×0.0103λ at 1.94 GHz) and it produces symmetrical monopole type radiation pattern at all tunable bands.

A compact CPW-based dual-band filter using modified complementary split ring resonator

In this paper, a compact coplanar waveguide (CPW) based dual-band bandpass filter has been proposed. The modified complementary split ring resonator (CSRR) structure at CPW ground plane is investigated for designing of dual-band bandpass filter with minimum insertion loss. The zeroth order resonance (ZOR) frequency depends on shunt parameter due to open ended boundary condition. The dual-band bandpass filter with return loss 21 and 20 dB, insertion loss 0.5 and 0.4 dB at 1.8 and 3.2 GHz, respectively, are simulated and measured. The measured 3 dB fractional bandwidths are 92.7% and 18.8% with respect to their centre frequencies of passbands. The simulated and measured results are showing good agreement in the passband. The electrical size of designed filter is 0.10λ0 × 0.09λ0 × 0.007λ0, where λ0 is the free space wavelength at the resonance frequency of first pass band. It is suitable for a global system for mobile (GSM) and long term evolution (LTE) in different service bands of 900, 1800, 1900 and 2300 MHz wireless communication applications.

A frequency reconfigurable antenna with Bluetooth, Wi-Fi and WLAN notch band characteristics

A compact coplanar waveguide fed reconfigurable antenna with three notch bands are presented in this paper. Proposed antenna reconfigurability is acquired by placing bar6404 PIN diodes in the S-shaped ground plane in right to left mode and left to right mode. By switching the diode, reconfigurability achieved for three different operations. The substrate material for the proposed antenna is FR4 with dielectric constant 4.4 and loss tangent 0.02. The overall dimension of the reconfigurable antenna is around 30×26mm2. It is being observed in this work for the cause of each individual slot on notch band characteristics. The measured gain for the designed reconfigurable antenna is quite stable at operating frequencies except notch bands. The proposed antenna is suitable for practical wideband applications with notching.

Multi-port Pattern diversity antenna for K and Ka-band application

A compact coplanar waveguide (CPW) fed reconfigurable antenna with pattern diversity using multi-port excitation is designed. The basic antenna consists of a circular patch of radius 2.5mm which is fed by four ports independently. By exciting the patch with each individual port, the direction of the radiation pattern changes by 900. With the use of CPW feed technique, a very wide impedance bandwidth of around 12GHz (21.65 – 33.87 GHz) covering the K-band and Ka-band is achieved. The proposed antenna can be used for different satellite communication applications like earth exploration, radio navigation and location, mobile satellite communications which comes under K-band and Ka-band. The measured return loss and pattern characteristic results are in good agreement with simulated ones.

De-embedding technique for accurate modeling of compact 3D MMIC CPW transmission lines

Requirement for high-density and high-functionality microwave and millimeter-wave circuits have led to the innovative circuit architectures such as three-dimensional multilayer MMICs. The major advantage of the multilayer techniques is that one can employ passive and active components based on CPW technology. In this work, MMIC Coplanar Waveguide(CPW)components such as Transmission Line (TL) are modeled in their 3D layouts. Main characteristics of CPWTL suffered from the probe pads’ parasitic and resonant frequency effects have been studied. By understanding the parasitic effects, then the novel de-embedding technique are developed accurately in order to predict high frequency characteristics of the designed MMICs. The novel de-embedding technique has shown to be critical in reducing the probe pad parasitic significantly from the model. As results, high frequency characteristics of the designed MMICs have been presented with minimumparasitic effects of the probe pads. The de-embedding process optimises the determination of main characteristics of Compact 3D MMIC CPW transmission lines.

Broadband compact CPW-fed metasurface antenna for SAR-based portable imaging system

A broadband and compact coplanar waveguide (CPW) coupled-fed metasurface (MS)-based antenna for C-band synthetic aperture radar (SAR) imaging application is proposed in this article, which is consisted of 16 uniform periodic square patches performed as radiators. The CPW feeding structure gives two following functions: (1) It excites an aperture coupling slot structure underneath the center of MS patch array. (2) It acts as a ground plane for the metasurface patch units. Different slots were investigated and eventually an hourglass-shaped slot is applied to enhance bandwidth for imaging applications. A prototype with a dimension of 60 × 60 × 1.524 mm3 (1.1λ0 × 1.1λ0 × 0.03λ0) operating at the center frequency 5.5 GHz (f0) has been fabricated and measured to verify the design principle. This antenna has a measured impedance bandwidth of 12.4% from 5.14 to 5.82 GHz, a peak gain of 9.2 dBi and averaged gain of 7.2 dBi at broadside radiation. Microwave imaging experiments using the proposed antenna have been carried out and a good performance is achieved.

Design optimization of CPW-fed microstrip patch antenna using constrained ABFO algorithm

This paper explores the potential of bio-inspired soft computational technique known as adaptive bacterial foraging optimization (ABFO) for the joint optimization of geometrical parameters of compact coplanar waveguide (CPW)-fed microstrip patch antenna with defected ground structure. The presented research work is divided into three phases. In the initial phase, the intended antenna is designed and analyzed using finite element-based electromagnetic simulator Ansoft HFSS 15.0. In the subsequent phase, the analytical equations of various design parameters are modeled using curve fitting technique in MATLAB and root mean square error-based fitness functions are derived for individual design parameters. Then, a joint cost function is formulated from individual fitness functions for evaluation in optimization algorithm. Adaptive BFO is an improvement in classical BFO algorithm that dynamically adjusts the run-length unit parameter to maintain the balance between exploration–exploitation trade-off. In the final phase, a variation in the adaptive BFO algorithm termed as ‘constrained ABFO’ is projected and designed to suit the bounded constraints imposed by anticipated antenna structure. The modified algorithm is efficaciously used for joint optimization of specific design parameters to transform ‘dual-band performance’ into ‘broadband performance’ for high-speed point-to-point wireless services. The performance of design optimization using constrained ABFO is compared with the original BFO, particle swarm optimization (PSO), hybrid bacterial foraging–particle swarm optimization (BF-PSO), invasive weed optimization (IWO) and artificial bee colony (ABC) techniques to scrutinize its adequacy.

Multiband SRR loaded leaf-shaped Koch fractal with a modified CPW-fed antenna

ABSTRACTIn this article, a compact co-planar wave-guide (CPW) feed leaf-shaped Koch fractal antenna loaded with a circular split ring resonator (SRR) is presented. The proposed design consists of a leaf patch etched with Koch fractal (top) and an SRR loaded beneath the FR4, which are accountable for achieving multiple band characteristics, smallness, and fine impedance matching. The antenna dimension is 14×16×1.6 mm3 and is fabricated and tested. The testing results show that the design proposed, having −10 dB for 1.977, 3.19, 6.32, 8.814, 11.87, 15.69, and 18.3 GHz, respectively, covers L/S/C/X/Ku/K bands. It has good radiation characteristics for both E and H fields in all the operating bands and also it generates superior performances compared to the existing antenna in the reviews. The modified CPW-fed leaf-shaped Koch fractal SRR structure antenna is validated through negative permeability extraction and different parametric studies.

SRR loaded CPW‐fed multiple band rose flower‐shaped fractal antenna

AbstractIn this article, a compact coplanar waveguide (CPW) faded rose flower shaped fractal antenna is presented. The proposed design consists of a rose patch (top) and a split ring resonator loaded beneath the FR4, which are accountable for achieving multiple band characteristics, smallness, and fine impedance matching. The SRR rose antenna with a compacted dimension of 12 × 12 × 1.6 mm3 is fabricated and tested. The testing results show that the design proposed, having −10 dB for 1.031, 4.591, 8.284, 13.41, and 17.17 GHz, respectively, covers WLAN/IEEE 802.16/Wi‐MAX/ITU bands. It has fine radiation characteristics for both E field and H field in all the preferred operational bands and generates superior performances compared to the existing designed antenna in the reviews. The loaded rose fractal SRR structure recital is validated through negative permeability extraction and different parametric studies.

Co-simulation of a complete rectenna with a circular slot loop antenna in CPW technology

This study starts with the design of a planar and compact CPW antenna fabricated on Arlon AD1000 substrate, εr=10.35. The antenna is a coplanar waveguide (CPW) fed circular slot loop antenna matched to the standard impedance 50 Ω by two stubs. The goal is to implement this antenna with a CPW RF/DC rectifier to build an optimized low power level rectenna. The rectenna design is restricted to allow easy and fast fabrication of an array with a high reproducibility. The full rectenna is simulated and achieves 10% effciency at −20 dBm.

A Dual-Beam Eight-Element Antenna Array With Compact CPWG Crossover Structure

In this letter, a dual-beam eight-element antenna array is proposed with compact coplanar waveguide with ground (CPWG) crossover structure. The feeding network is composed of a microstrip-line feeding network with four 90° hybrids and a CPWG feeding network with compact crossover structures. Compared to the conventional Butler matrix feeding network, the proposed network has fewer 90° hybrids and circuit is less complex. By exciting different port of the feeding network, the eight-element antenna can be excited by phase step of 22.5° or –22.5° and achieve two beams pointing at two different directions. The measured gain is 10.2 dBi, and beam directions of the two peaks are ±7° at 5.8 GHz.

A novel coplanar waveguide resonator on flexible substrate

In this paper a flexible coplanar waveguide resonator with high quality factor is proposed and fabricated. The device consists of a compact coplanar waveguide (CPW) and two complementary split rectangle resonators (CSRR) locating between the central signal wire and the ground plane of the CPW. The designed and measured values of frequency, attenuation, and quality factor of the resonant dips are 31.9GHz and 31.8GHz, −45dB and −12dB, and 115.7 and 35.1, respectively. The differences between the simulated and measured values of attenuation and quality factor are due to the imperfectmetal structure. The frequency of the resonant dip is very sensitive to dielectric environment. This chip device is very promising for biomedical and sensing applications.

Compact MIMO antenna for indoor UWB applications

ABSTRACTA compact coplanar waveguide (CPW)‐fed multiple‐input‐multiple‐output (MIMO) antenna for indoor ultrawideband (UWB) applications is presented. The overall size of the antenna is 31 × 43 mm2. To increase the isolation factor, the common ground plane (CGP) is reinforced with a set of corrugations and frills and the outer ground plane of the first port is self‐coupled. The radiators are designed perpendicular to each other in order to improve the pattern diversity. The measured results show the antenna operates at frequency range 3.9–8.1 GHz. The mutual coupling of less than −15 dB in almost all over the bandwidth, achieving a −31 dB at 5.4 GHz, proposes it as a good candidate for UWB applications in indoor systems. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2387–2393, 2016

A compact CPW-fed wideband metamaterial-inspired antenna for GSM, WLAN/Wi-Fi, and WiMAX applications

A compact coplanar waveguide (CPW)-fed wideband metamaterial-inspired antenna is designed and developed in this paper. The proposed structure is an asymmetric structure in which three rectangular stubs are employed between signal patch and CPW ground plane. It is demonstrated that these stubs provides lumped parameters of conventional epsilon-negative transmission line (ENG-TL). As an advantage of these stubs proposed antenna operates on 1.67–2.76 GHz with −10 dB impedance bandwidth of 49.2%. The proposed antenna having small electrical size of 0.17λ0 × 0.35λ0 × 0.01λ0 at fo = 2.21 GHz. The simulated average gain and radiation efficiency of the proposed antenna is 1.61 dB and 96.33% respectively throughout the bandwidth. Properties such as smaller electrical size, simpler design, consistent radiation characteristics, and ease of fabrication are making this antenna suitable for GSM, WLAN/Wi-Fi, Bluetooth, and WiMAX applications.

A Novel Linear Array Antenna Based on UWB Slot Antenna

This paper introduces the novel Ultra-Wide Band (UWB) antennas for UWB applications. We used two different structures, the first is fed by micro-strip line and the second is a compact coplanar waveguide fed planar slot antenna. These designs are a small on planar antenna. The substrate used is FR4 that have the characteristics following: Permittivity εr = 4.4 Impulse Radio Ultra Wide Band systems (IR-UWB). The frequency central is 5.6 GHz and shows good characteristics for IR-UWB. The radiation pattern and gain are simulated and we compared between the different results we have obtained.