Compact Coplanar Waveguide Research Articles

Compact CPW UWB diversity slot antenna with dual band‐notched characteristics

ABSTRACTA compact coplanar waveguide (CPW) fed ultrawideband (UWB) slot antenna for multiple‐input‐multiple‐output (MIMO)/diversity applications is presented in this letter. The antenna consists of two coplanar waveguides (CPWs) feeding circular radiating elements and a protruded stub, which is placed at between them. The circular radiating elements are arrange orthogonally and fed perpendicularly to obtain polarization diversity. Notched band at X‐band communication downlinks is achieved by etching split ring resonator slots in the radiators and the other notched band at WLAN system is achieved by the collaboration of arc‐shaped strips and the protruded stub. The protruded stub not only can help to achieve band rejection but also can reduce mutual coupling between two ports. As all of the structures are printed in one layer, it can be very easily to be integrated with RF front‐end circuits. Simulated and measured results show that the proposed antenna meets the 10‐dB impedance bandwidth from 3.4 to 12 GHz and isolation better than 15 dB at most of the band. Good diversity performance in terms of envelope correlation coefficient and the ratio of mean effective gain demonstrates that the antenna is quite suitable for MIMO UWB applications. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:989–994, 2016

Triple Frequency Notch in UWB Antenna with Single Ring SRR Loading

A compact coplanar waveguide (CPW) fed ultrawideband (UWB) printed circular monopole antenna (PMA) with triple frequency notched function is presented and validated here on a low cost FR4 Epoxy substrate. Here the antenna loaded with three single circular ring SRRs to create triple frequency notching in 3.5GHz for WiMAX, 5.5GHz for WLAN, and 7.9GHz for X-band satellite communication systems, respectively. The SRR design equations are analyzed in detail here. Return loss and voltage standing wave ratio (VSWR) are used to show the effect of these rings. Measured result shows a close correlation to the theoretical results.

TUNABLE BAND-NOTCHED CPW-FED UWB MONOPOLE ANTENNA USING CAPACITIVELY LOADED MICROSTRIP RESONATOR FOR COGNITIVE RADIO APPLICATIONS

In this paper, a new compact coplanar waveguide (CPW) ultrawideband (UWB) antenna with an electronically tunable notched band is proposed for an overlay onto cognitive radio (CR) systems. The proposed antenna utilized a rectangular microstrip resonator in the bottom layer to create a single notched band and to realize tunability and miniaturization using varactors. The center frequency of the notched band can be electronically tuned by changing the effective electrical length of the microstrip resonator, which is achieved by employing two varactor diodes at the resonator edges. Moreover, the simple biasing of the varactor diodes has a small effect on the antenna performance. Experimental results show that the proposed antenna can selectively have a band notch over a continuous operating band about 1.44 GHz from 4.77 to 6.21 GHz to prevent the interference to the primary users that are operating in this band such as the WLAN (5.15-5.35 GHz; 5.725-5.825 GHz) and the WiMAX (5.25- 5.825 GHz). Good agreement is found between the simulated and the measured data.

Compact Triple-Band Antenna Employing Simplified MTLs for Wireless Applications

A compact triple-band asymmetric coplanar waveguide- (ACPW-) fed antenna based on simplified metamaterial transmission lines (SMTLs) is proposed in this paper. The antenna consists of two SMTL unit cells of the same dimension. Three operating bands, which cover UMTS in the 1.76 GHz band and WLAN in the 5.2 GHz and 5.8 GHz, are achieved when the zeroth-order and first-positive-order modes appear. The characteristics of the proposed transmission line metamaterial structure are studied in detail by circuit analysis and dispersion analysis. The working mechanism and radiation performances of the antenna are examined and illustrated at the three operating bands, respectively. A prototype designed on FR4 substrate with dielectric constant 4.3 occupies an overall size of 12.55 × 22.7 × 1.6 mm3and is constructed and successfully measured.

A compact UWB bandpass filter based on CRLH via‐less CPW‐fed

ABSTRACTA novel compact coplanar waveguide (CPW)‐fed ultrawideband (UWB) bandpass filter is proposed in this article. The composite right‐/left‐handed transmission line structure is designed on a single layer via‐less CPW‐fed, which reduces the fabrication complexity and makes the structure more feasible. The filter exhibits stopband rejection level greater than 10 dB while maintaining insertion loss less than 0.3 dB throughout the passband range. The filter has a compact size of 18.4 mm × 4.5 mm. The performance of the proposed UWB bandpass filter is compared with the previously reported UWB bandpass filters. All the performance parameters of the filter are evaluated by full‐wave electromagnetic simulator IE3D, based on the method of moments and all the results are verified by measurement. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:276–279, 2016

A compact zeroth‐order resonator based on CRLH via‐less CPW‐fed

ABSTRACTA novel compact coplanar waveguide (CPW)‐fed zeroth‐order resonator (ZOR) is reported in this article. The zeroth‐order mode is required to reduce the resonator's size. The composite right/left handed transmission line (CRLH TL) structure is designed on a single layer via‐less CPW‐fed, which reduces the fabrication complexity and makes the structure more feasible. The resonator has a compact size of 21.6 × 5.2 mm2. The measured insertion loss and return loss of the resonator are −0.72 dB and −21.3 dB, respectively at the resonant frequency, 2.80 GHz. The performance of the proposed ZOR is compared with the previously reported ZORs. All the performance parameters of the resonator are evaluated by full‐wave electromagnetic simulator IE3D, based on the method of moments (MoM) and all the results are verified by measurement. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2576–2580, 2015

Study of CPW-Fed Slot Antenna for UWBApplication

Compact coplanar waveguide (CPW) fed slot antenna for ultra-wideband (UWB) application is presented. Many UWB antennas have been developed to cover the ultrawide operating bandwidth of the UWB systems with acceptable performance. Currently, the prospective applications of UWB technology are becoming clearer and clearer. The majority of UWB R&D activities have been focused on how to meet the specific requirements of forthcoming UWB systems. This paper will review the R&D of UWB antennas since 2002 with proposed design model. A 50-Ω coplanar waveguide transmission line is used to fed slot antenna. Various slits on the ground plane is done for bandwidth enhancement. CPW fed slot antennas are attractive due to low dispersion and ease of integration with active and passive devices. CPW-fed slot antenna exhibit perfect impedance matching, broadside radiation patterns, and low cross polarization. Analysis of the effects of various slot dimensions on the parameters of the antenna design has been done.

Wide Band CPW Fed Slotted Microstrip Antenna

In this paper, a design of compact coplanar waveguide fed UWB slot antenna is presented. The proposed antenna has simple structure consisting rectangular slot with uneven coplanar ground structures. The proposed antenna structure is investigated by using MoM based electromagnetic solver IE3D. The simulation and measured results show that the antenna offers performance for wideband system from 4.5 GHz to11.8 GHz with return loss better than -10dB over the frequency spectrum with VSWR less than 2.5. The antenna configuration would be quiet useful for indoor applications. The antenna is fabricated and simulated. Measured results show a good agreement with simulated results. DOI: http://dx.doi.org/10.11591/telkomnika.v15i1.8078

Compact CPW‐fed triple‐band antenna for diversity applications

A compact coplanar waveguide (CPW)-fed triple-band monopole antenna with high-band isolation for various wireless applications is presented. The proposed antenna is composed of a CPW-fed structure and a hexagon-shaped patch on which a hexagon-shaped slot is etched for covering the wireless local area network (WLAN) band (2.4/5.2/5.8 GHz), and occupies a very compact size of 26 × 25 mm2. By introducing a half-hexagon-shaped stub, additional bands can be realised covering the worldwide interoperability for microwave access (WIMAX) band (2.5/3.5/5.5 GHz). The proposed antenna has been fabricated and measured; results show a higher isolation between adjacent bands, good radiation pattern characteristics and stable gains in the operating bands. The simple feeding structure, compact size and uniplanar design make it easy to be integrated within portable devices for wireless communication.

Compact coplanar waveguide bandpass filter based on coupled S‐shaped split ring resonators

ABSTRACTThis letter is focused on the application of coupled single‐layer S‐shaped split ring resonators (S‐SRRs) to the design of highly compact bandpass filters in coplanar waveguide (CPW) technology. S‐SRRs have been previously demonstrated as miniaturized resonators, particularly suited for applications in conjunction with coplanar line geometries. However, size reduction of CPW filters based on impedance inverters and S‐SRRs is limited by the inverters. Therefore, this letter proposes an alternative geometry of CPW bandpass filters employing S‐SRRs in a configuration based on the theory of coupled resonators. A highly compact third‐order bandpass filter is designed using this principle, and the proposed approach is validated through experiment, demonstrating competitive filter performance achieved in an extremely small area. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1113–1116, 2015

Design and compare of Two Coplanar Fed Ultra Wideband Antenna

this paper, design and analysis of two compact coplanar waveguide (CPW) fed ultra wideband (UWB) slot antenna is presented. The proposed antenna consists of a rectangular slot on a ground plane and a triangular patch and another semi- circular patch at the interior portion of the feed that acts as tuning stub of the antenna. The return loss of the developed antenna are measured and compared, which shows that measured result is in good agreement with simulation. It is also seen that the proposed antenna has relatively stable Omni directional radiation pattern in the H plane and bidirectional radiation pattern in the E plane over the frequency range of 3.91 GHz to 10.6 GHz. Keywordsot Antenna, Coplanar Waveguide, Return Loss, Ultra Wideband

Coplanar Waveguide Filter using Stub Resonators for Ultra Wide Band Applications

The paper presents a compact coplanar waveguide filter employing stub resonators for ultra wide band applications. A cascade connection of series and shunt stubs quarter wavelength long is used for achieving bandpass characteristics. The performance requirement of the filter decides the number of cascaded sections. The filter has reduced insertion loss in its passband and good attenuation in lower and upper stopbands. The flat group delay in the passband ensures its use in communication applications. Measured frequency response of the fabricated prototype shows good agreement with simulated response.

Semi fractal three leaf clover-shaped CPW antenna for triple band operation

This article presents a unique and compact coplanar waveguide CPW antenna that exhibits triband operation with circular polarization. The single antenna was designed to operate simultaneously in the following bands: WiMAX 3.3-3.6 GHz, wireless local area network WLAN 5.15-5.825 GHz, ITS 5.795-6.400 GHz, and ITU-R 7.725-8.5 GHz. The realization of the triband antenna was achieved by using two semi fractal ring patches resembling the shape of a three leaf clover, and by introducing a pair of symmetrical L-shaped slits in its ground plane. The antenna's physical parameters were investigated to fully understand their affect on the antenna's performance. The salient parameters obtained from this analysis enabled the optimization of the antenna's overall characteristics. The design concept was confirmed by fabricating the antenna prototype and measuring its characteristics. The proposed antenna has dimensions of 20 × 20 × 1 mm3. Measured results show the antenna exhibits circular polarization in WiMAX and ITU-R bands, and linear polarization in the WLAN band. The antenna radiates omnidirectionally in the H-plane, and approximately bidirectionally in the E-plane. In addition, the antenna presents stable gain over the triband. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:413-418, 2015.

Investigation of Compact Tree-Shaped Coplanar Waveguide (CPW) Antenna for RF Energy Harvesting

This paper studies a compact wideband tree-shaped coplanar antenna which has the potential to be used for RF energy harvesting. The antenna is fabricated on a double-sided FR-4 printed circuit board using an etching technique. The effect of semi-circle patch embedded to a triangular patch has been studied. The comparison between simulation and measurement results for the return loss and radiation patterns are observed and are in good agreement. The measured return loss is in line with the simulation response where both manage to achieve lower than-10dB. A bandwidth of 3.64 GHz and 3.94 GHz were obtained in simulation and measurement process respectively. This study is an early investigation in designing the antenna for RF energy harvesting system to support green technology and sustainable development particularly for Wireless Sensor Network (WSN).

New π –T generalised metamaterial negative refractive index transmission line for a compact coplanar waveguide triple band pass filter applications

This study presents, for the first time, a novel π − T generalised negative refractive index (NRI) transmission line (TL) configuration. It is innovated for increasing the possible passbands in designing microwave components. It is proved that the proposed transmission line can introduce up to seven passbands for completely unbalanced transmission line condition. The detailed mathematical analysis of that configuration based on the periodic network analysis and equivalent circuit model is introduced. As an application for the novel π − T generalised NRI TL configuration, a new compact triple band coplanar waveguide (CPW) metamaterial filter is introduced. The proposed triple bands CPW filter design steps are introduced and its performance is validated using equivalent circuit model simulation, electromagnetic full wave simulation and experimental measurements. Good agreements between the circuit modelling, electromagnetic full wave simulation and practical measurement results are achieved. All the results confirm that the proposed filter has triple passbands from 900 to 960 MHz, 1.4 to 1.48 GHz and 2.4 to 2.45 GHz. Moreover the filter size is compact whose length is only 12.1% λg at first passbands, 18.2 λg % at second passbands and 31.7 λg % at third passbands.

CPW Center-Fed Single-Layer SIW Slot Antenna Array for Automotive Radars

A compact co-planar waveguide (CPW) center-fed substrate-integrated-waveguide (SIW) slot antenna array is proposed to achieve narrow H-plane beamwidth and low sidelobe levels for automotive radars such as across-the-road (ATR) radar. The antenna consists of an array of SIW slot elements, a CPW-SIW transition, and a CPW power divider. A new type of CPW-SIW transition is proposed to minimize the blockage aperture of the slot antenna array for suppressing the sidelobe levels of the array. A parallel center feeding configuration is applied to avoid beam squinting. The antenna prototype printed onto a single-layer Rogers 5880 is with 32 ×4 slot elements and an overall size of 195 mm×40 mm×0.79 mm. Measured results show that the proposed antenna exhibits a gain of > 22.8 dBi, an efficiency of > 67%, a return loss of > 10 dB, a sidelobe level of <;-21 dB, and a fixed boresight beam of <;4.6° in H-planes over 24.05-24.25 GHz, suitable for ATR radar.

A CPW-fed reconfigurable patch antenna with circular polarization diversity

This paper presents a simple and compact coplanar waveguide (CPW)-fed circular-shaped reconfigurable patch antenna with a switchable circular polarization (CP) sense. The circular patch is cut at the ends vertically and switches are introduced to connect the patch ends. By controlling the ON/OFF status of the two switches, the polarization of the antenna can be switched between two states: left-hand circular polarization and right-hand circular polarization. The patch is designed on a very thin RT Duroid substrate of dielectric constant (εr) of 2.2 and thickness of 0.254 mm. The overall antenna dimensions are 35 × 30 mm. The antenna is designed and simulated using finite-element method -based EM simulator, HFSS. For each switching condition the return loss curve, radiation pattern are obtained. Axial ratio curves for polarization diversity cases are also plotted. Parametric studies have been made in order to get optimized values for certain antenna dimensions such as thickness, CPW ground to feed gap, etc.

A CPW‐fed circular wide‐slot UWB antenna with dual‐notch bands by combining slot and parasitic element techniques

ABSTRACTA compact coplanar waveguide fed circular wide‐slot antenna with dual‐band‐notched characteristic is proposed by using an arc‐shaped slot (ASS) and an arc‐shaped parasitic element (ASPE) for ultra‐wideband (UWB) communication applications. The center frequencies of the dual‐notch bands can be tuned in a wide range by adjusting the parameters of the ASS and the ASPE. Both the numerical and experimental results show that the proposed antenna can operate over a wide frequency band ranging from 2.7 to 12 GHz with VSWR &lt; 2, with the exception of the two notch bands operating at wireless local area network band and X‐band. In addition, the proposed antenna has a compact size and omnidirectional radiation pattern, which is suitable for UWB communication applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1240–1244, 2014

A CPW-fed circular slot UWB antenna with WLAN band and X-band filtering characteristics using hybrid resonators

A compact coplanar waveguide (CPW)-fed circular slot ultrawideband (UWB) antenna with dual-band filtering characteristic is presented in this article. The dual-band filtering characteristic is achieved by inserting an arc-rectangle-shaped stepped impedance resonator in the circular ring radiation patch and etching a spiral stepped impedance resonator in the CPW-fed transmission line. The numerical and experimental results demonstrate that the proposed antenna can operate on a frequency band between 2.7 and 12 GHz with voltage standing wave ratio less than 2, except for that two filtering bands between 4.8 and 6 GHz and between 7.6 and 8.6 GHz are used to prevent the potential interference from WLAN band and X-band. In addition, the proposed antenna has a compact size and omnidirectional radiation pattern, which is suitable for UWB communication applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:925–929, 2014

Compact CPW fed electrically small antenna for WLAN application

A compact coplanar waveguide (CPW) fed electrically small antenna suitable for 2.4 GHz WLAN applications is presented. The resonance of the structure is achieved by implanting a chip inductor in between the centre conductor of an open-ended CPW transmission line and a short metal strip. The total electrical size of the fabricated antenna is 0.08λ 0 × 0.0479λ 0. The reflection and radiation characteristics of the antenna and a method to enhance the gain are discussed.