Coplanar Waveguide-fed Slot Antenna Research Articles

Development of CPW Fed Slot Antenna with CSRR for Biomedical Applications

This paper presents a complementary split-ring resonator (CSRR) loaded coplanar waveguide (CPW) fed with a circular shape, miniaturized diamond slot planar monopole antenna. The proposed antenna for healthcare monitoring biomedical applications uses the industrial medical and scientific band. The antenna design and development to implant the human phantom are proposed. The primary goal of this work is to continuously monitor the patient’s ability to detect abnormal conditions as soon as possible as a result of improvements in quality of life. In this case, an antenna design methodology must prioritize features such as miniaturization, increased gain and bandwidth, and biocompatibility. Simulated and measured antenna characteristics for biomedical applications are performed at ISM Band frequency.

CPW Fed Wideband Corner Bent Antenna for 5G Mobile Terminals

A co-planar waveguide fed slot antenna element with 34% impedance bandwidth and 2-3 dBi broadside gain is proposed. The corner bent topology of the element is investigated for reduced physical footprint and easier integration with the mobile terminals operating in the 28-GHz band. The front-to-back ratio of the corner bent antenna is 1 dB in the xy plane, which indicates a high specific absorption rate. A compact wideband reflector is proposed which has transmission of less than -25 dB and a linear phase ±90° in the 27-33-GHz bandwidth. The wideband reflector is integrated with the corner bent antenna at 0.135λ offset from the radiating aperture. The corner bent antenna integrated with the reflector operates in the 27-33-GHz band, with a front-to-back ratio of more than 14 dB across the band and a forward gain of 6-7.2 dBi. The radiation patterns are stable for 20% bandwidth. The simulated and measured results are presented.

Design and performance analysis of broadband rectenna for an efficient RF energy harvesting application

This article proposes the design of coplanar waveguide (CPW) fed broadband rectenna for radio frequency (RF) energy harvesting application. The rectenna is designed to operate in the industrial, scientific, and medical (ISM) frequency band of 5.8 GHz. For designing the proposed rectenna, polytetrafluoroethylene (PTFE) dielectric material was used to design, fabricate the CPW fed slot antenna. It was observed that the proposed antenna exhibits the |S11| of −23.43 dB and achieves the peak antenna gain of 8.56 dBi at 5.8 GHz. Secondly, the CPW fed rectifier circuit which comprises of the matching circuit, rectifying unit, and filter was designed. The measured results showed that the |S11| of −19 dB and it was perfectly matched with 50 Ω impedance. Finally, the rectenna was designed by integration of antenna with rectifier circuit. The simulated results showed the maximum RF to direct current (DC) conversion efficiency and the output DC voltage of 88% and 445 mV at the load resistance of 1 kΩ. The measured results show the maximum RF to DC conversion efficiency of 73.4% with the output DC voltage of 540 mV at the load resistance of 1 kΩ.

분할 링 공진기를 이용한 소형 이중 대역 CPW-급전 슬롯 안테나

In this paper, a design method for a compact dual-band coplanar waveguide-fed slot antenna using SRR(split-ring resonator) conductor is studied. The SRR conductor is loaded inside a rectangular slot of the proposed antenna for dual-band operation. When the SRR conductor is inserted into the slot, the original rectangular slot is divided into a rectangular loop region and a rectangular slot region, and frequency bands are created by the loop and slot, separately. A prototype of the proposed dual-band slot antenna operating at 2.45 GHz WLAN band and 3.40-5.35 GHz band is fabricated on an FR4 substrate with a dimension of 30 mm by 30 mm. Experiment results show that the antenna has a desired impedance characteristic with a frequency band of 2.38-2.51 GHz and 3.32-5.38 GHz for a voltage standing wave

Bandwidth enhancement in coplanar waveguide‐fed slot antennas designed for wideband code division multiple access/wireless local area network/worldwide interoperability for microwave access applications

A multiband coplanar waveguide-fed slot antenna design is proposed for use in wireless and mobile communication applications. This antenna was designed on a single-layer printed circuit board FR4 substrate featuring a permittivity ɛ r = 4.4, a loss tangent tan δ = 0.0245 and a thickness of h = 1.6 mm. The antenna consists of a T-shaped signal strip and a U-shaped conducting strip placed on the upper side of the T-shaped signal strip. After simply tuning the slot parameters of the ground plane, the proposed antenna can be used in the following operations: wireless local area networks at 2.4/5.2/5.8 GHz, worldwide interoperability for microwave access at 2.5/3.5/5.5 GHz and wideband code division multiple access at 1.92–2.17 GHz. The −10 dB bandwidth measured for the proposed antennas was 109.2% (1.85–6.3 GHz). The bandwidth was enhanced by choosing suitable combinations of the upper and lower ground slots. The geometrical parameters were examined to optimise the performance of the proposed antenna. The results of the return loss, far-field H- and E-planes radiation patterns, gain and radiation efficiency of the proposed antenna are presented and discussed herein. The antenna size of the radiation area and the ground plane was 50 × 50 mm2. Detailed simulations and experiments were conducted to optimise broadband operations, and the measured results concurred with the simulated results.

A circularly polarized slot antenna for high gain applications

A coplanar waveguide fed slot antenna for wideband circular polarization is designed and experimentally validated. The rectangular slot is excited using a stepped feed line terminated on a circular disc shaped tuning stub. To obtain circular polarization, inverted L-shaped strips are attached to the ground plane at the opposite corners while a rectangular slit is cut in the circular disc. The combined bandwidth (3-dB axial ratio and 10dB impedance matching) achieved is 48% (4.35–7.1GHz) under simulation and 40% (4.75–7.1GHz) in measurement. The gain of the antenna is next enhanced by the application of a double layered square loop frequency selective surface. The frequency selective surface is used as a reflector placed beneath the antenna at an optimum distance. An improvement of about 4dB is seen in the measured peak gain over most of the operating band. Experimental results are presented to characterize the antenna and the frequency selective surface and they are found to be in good agreement with the simulated results.

DESIGN OF CPW-FED DUAL-BAND PRINTED MONOPOLE ANTENNAS FOR LTE/WIMAX/WLAN AND UWB APPLICATIONS

In this paper, two miniaturized (20 × 20 mm 2 ) coplanar waveguide fed slot antennas are proposed. Both the antennas are characterized by ultra wide impedance bandwidth while one of them has an additional narrow band near 2.5 GHz. The radiating element of the proposed antennas is a modified rectangular geometry which is excited by a 50 ohm line. The slot in the ground plane is stair case shape for UWB antenna and octagonal shape for the dual-band antenna. By modifying the slot and adding a λ/4 length metallic stub, an extra resonance is created for the dual-band antenna. The measured impedance bandwidth of the UWB antenna is 7.8 GHz (3.4-11.2 GHz). The impedance bandwidths of the dual-band antenna are 150 MHz (2.45-2.6 GHz) and 8.4 GHz (3.2-11.6 GHz). The radiation patterns of the proposed antenna are found to be bi-directional in E-plane and omni-directional in H-plane. All the measured and simulated results are in good agreement.

CPW fed slot antenna with reconfigurable rejection bands for UWB application

A coplanar waveguide (CPW) fed ultra wideband slot antenna with reconfigurable band rejection characteristics is presented. Ultra wide bandwidth of 3.01–10.6 GHz is achieved by exciting the rectangular slot antenna with C-shaped stub. Band notch characteristic is changed between WLAN and WiMAX band by the integrated switches placed across the half wavelength slot. The performance of the proposed antenna is investigated numerically and experimentally. Experimental results demonstrate that the antenna exhibits omni directional characteristics with the peak gain of 4.9 dB and a gain variation of less than 2 dB across the operating band.

BROADBAND CPW-FED CIRCULARLY POLARIZED ANTENNA WITH AN IRREGULAR SLOT FOR 2.45 GHZ RFID READER

A coplanar waveguide-fed slot antenna with wideband circular polarization characteristic is presented. The proposed antenna consists of an irregular slot with a stair-shaped edge and an L-shaped feed line. The stair-shaped edge can improve the circular polarization of the antenna. The simulated and measured results show that the antenna has an impedance bandwidth (VSWR < 2) about 1040MHz (42%@2.47GHz) and an axial ratio (AR) bandwidth (AR < 3dB) about 640MHz (25.8%@2.48GHz) for 2.45GHz RFID applications. The RHCP gain in the main radiation direction varies between 2.3dBi and 3.8dBi.

Coplanar waveguide-fed slot antenna for wireless local area network/worldwide interoperability for microwave access applications

Owing to the recent demand to incorporate the two communication services, the wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX), therefore dual-band antennas that are designed with sufficient bandwidths to cover both WLAN and WiMAX operating bands are presently very important topics of research. Owing to the difficulty of simultaneously achieving both compactness and wideband, the dimensions of most dual-band slot antenna designs that are reported in recent literature exceed 35×40 mm2. Therefore this study presents a compact (32×32 mm2) coplanar waveguide (CPW)-fed slot antenna design with dual-band operation for WLAN (2.4/5.2/5.8 GHz) and WiMAX (2.3/2.5/3.5/5.7 GHz) applications. To achieve wide 10 dB bandwidth for the lower operating band (58%), the technique of applying a square-ring slot antenna type with an asymmetric ground plane was used herein, and a broad upper operating band (32%) was attained by introducing a stub-protruded monopole and loading a double-bent stub into one of the asymmetric CPW ground planes. The process of designing the proposed antenna is explicitly shown, and parametric studies were carried out by simulation. Typical experimental measurements were also conducted and compared with the simulated results.

Wideband constant beamwidth coplanar waveguide-fed slot antennas using metallic strip loadings and a widened tuning stub with shaped reflectors

Sectored antennas with wideband operation for wireless communication systems are presented. The proposed configurations are based on a coplanar waveguide fed slot antenna using metallic strip loadings and a widened tuning stub above various reflector shapes. By shaping the reflector, noticeable enhancements in both unidirectional radiation pattern and beamwidth can be achieved while maintaining the simple fabrication and installation. Based on the results obtained, three sector antennas covering 72°, 90°, and 120° beamwidths suitable for five, four, and three sectors, respectively, have been proposed and designed. The simple structural configurations, low cost, and ease of half power beamwidth control of the proposed antennas make the design very attractive for practical implementation. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.

A Novel Coplanar Waveguide-Fed Slot Antenna for Ultrawideband Applications

A new coplanar waveguide-fed slot antenna for ultrawideband (UWB) applications is presented. The proposed X-shape antenna is analyzed both numerically and experimentally. The UWB characteristics of the antenna are achieved through the electromagnetic coupling between two adjacent slot arms. All the design procedures are performed by using CST MS software. The antenna operates with VSWR lower than 2.2 (S11< -8.5 dB) over the whole frequency band from 3.1 GHz to 10.6 GHz. In addition to the return loss, dispersion characteristic of the antenna is considered in the design procedure. A parametric study is presented to investigate the effect of the antenna geometrical parameters on its performance. The antenna shows fairly stable radiation pattern over the frequency range of interest. Furthermore, to analyze the dispersion behavior of the antenna, the frequency-domain and time domain characteristics of the antenna are investigated by means of the antenna transfer function.

CPW fed slot antenna for triple-frequency band operation

A novel design of a coplanar waveguide (CPW) fed slot antenna for achieving triple-frequency band operation is presented. The proposed antenna consists of two rectangular slot loop antennas and a single inset CPW feeder. Three resonant frequencies of the proposed antenna are mainly controlled by the dimensions of the two slot loops and coupling between antennas. The antenna prototypes are fabricated and their characteristics experimentally verified.

Design of a dual-band coplanar waveguide-fed slot antenna with wide frequency separation

This paper presents a novel design for a dual-band coplanar waveguide-fed-slot antenna that operates at 27GHz and 39GHz. Matching this antenna at the two widely separated frequencies is achieved using a special matching network of slot antennas. Experimental and numerical results are presented for the return loss and radiation patterns of this antenna.

Coplanar waveguide fed wideband slot antenna

A new design for a coplanar waveguide (CPW) fed slot antenna is presented. The impedance matching and the radiation characteristics of this structure were studied using the method of moment technique. This antenna has an impedance bandwidth (for a VSWR &lt; 2) of 49% and a radiation bandwidth of 42% about its 4.8 GHz centre frequency, compared to the 12–20% impedance bandwidth of the standard CPW fed slot antenna. The cross-polarisation in both the principle planes is at least 20 dB below co-polarisation across the entire bandwidth. Simulated and measured results of the antenna are presented. This wideband antenna has significant applications in wireless technologies.