Asymmetric Ground Plane Research Articles

Asymmetrically CPW-fed octagonal sierpinski UWB fractal antenna

An asymmetrically CPW-fed octagonal Sierpinski fractal antenna is designed for ultrawideband applications. It comprises of a second iterative fractal radiating patch, microstrip feedline and asymmetrical coplanar waveguide ground planes. An impedance bandwidth of 3.73 GHz to more than 20 GHz is achieved. Stable radiation patterns and desirable gain characteristics are observed. The simulated and experimental results are found to be in good agreement. The designed antenna structure has advantages of wide bandwidth and miniaturized dimensions over already reported UWB antenna structures. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1738–1745, 2016

COMPACT TRI-BAND DUAL-POLARIZED PLANAR MONOPOLE ANTENNA WITH ASYMMETRICAL GROUND PLANE AND LOADED STUB

This paper presents a compact tri-band dual-polarized planar monopole antenna, which is linearly polarized in the lower and middle bands and circularly polarized in the higher band. The antenna is printed on a substrate with an asymmetrical ground plane and a loaded vertical stub. The vertical stub and asymmetrical ground plane are mainly used to make the antenna obtain circular polarization performance in the higher band. The antenna has been built and tested. Its measured 10-dB impedance bandwidths are 2.39-2.54 GHz, 3.38-4.12 GHz, and 4.57-6.04 GHz, which can fully cover all the 2.4/5.2/5.8 GHz WLAN bands, all the 2.4/5.5 GHz Wi-Fi bands, and 3.5/5.5 GHz WiMAX bands. In the higher band, the measured 3-dB axial-ratio bandwidth is 5.4-5.83 GHz.

Design method for compensating lateral beam shift of ground-plane cloak

This paper demonstrates a method to improve the accuracy of the ground-plane cloak by compensating for the lateral beam shift. The lateral beam shift can be compensated by increasing the height of the bump with the upper boundary of the cloak and shifting the reference ground plane downwards in the cloaking region. Moreover, the asymmetric ground-plane cloak, which represents not only the lateral beam shift but also an error of the reflection angle, is also compensated by generating the initial grids unequally. The accuracy of the proposed method is verified via ray tracing simulation.

A novel CB ACS-fed dual band antenna with truncated ground plane for 2.4/5 GHz WLAN application

A novel conductor backed asymmetric coplanar strip (CBACS) fed dual band antenna which is suitable for wireless local area network is presented in this paper. The proposed antenna is composed of inverted L-shaped exciting strip, a lateral ground plane and a modified truncated ground plane on the backside with overall dimension of about 25mm×17.5mm×1.6mm. The proposed design comprises monopole patch with asymmetric coplanar ground plane with conductor backing exhibit dual band of response with measured bandwidth of return loss ≤−10dB is 2.30–2.55GHz and 4.06–6.65GHz which cover all the WLAN bands (2.4/5.2/5.8GHz). The parametric studies indicate that operating frequencies and wider bandwidth are determined by the dimension of the ground plane at the top and bottom. The proposed antenna covers IEEE 802.11a/b/HYPERLAN-2/RFID band with good radiation characteristics. The measurement of proposed antenna that has been printed on an FR4 substrate with dielectric constant 4.4 yields good conformity between simulated results. The proposed structure is simulated using the method of moment based electromagnetic solver IE3D version 15.10.

Bandwidth Enhancement Technique of the Meandered Monopole Antenna

A small dual-band monopole antenna with coplanar waveguide (CPW) feeding structure is presented in this paper. The antenna is composed of a meandered monopole, an extended conductor tail, and an asymmetrical ground plane. Tuning geometrical structure of the ground plane excites an additional resonant frequency band and thus enhances the impedance bandwidth of the meandered monopole antenna. Unlike the conventional monopole antenna, the new resonant mode is excited by a slot trace of the CPW transmission line. The radiation performance of the slot mode is as similar as that of the monopole. The parametrical effect of the size of the one-side ground plane on impedance matching condition has been derived by the simulation. The measured impedance bandwidths, which are defined by the reflection coefficient of −6 dB, are 186 MHz (863–1049 MHz, 19.4%) at the lower resonant band and 1320 MHz (1490–2810 MHz, 61.3%) at the upper band. From the results of the reflection coefficients of the proposed monopole antenna, the operated bandwidths of the commercial wireless communication systems, such as GSM 900, DCS, IMT-2000, UMTS, WLAN, LTE 2300, and LTE 2500, are covered for uses.

Design of a compact CPW-feed asymmetric elliptical slot ultrawideband antenna for high gain

ABSTRACTA compact, CPW‐feed slot antenna for ultrawideband applications is proposed. The antenna uses an elliptical patch as radiating element and an asymmetric slotted ground plane to provide a measured usable bandwidth of 120% (2.81–11.2 GHz). The asymmetric slot in the ground plane creates an extra inductive reactance which neutralizes the capacitive effect of the open ended elliptical patch and results into wider impedance matching. To improve the gain of the proposed antenna, a three metallic layer frequency selective surfaces (FSSs) of overall thickness 3.5 mm and with a stop band (transmission < −20 dB) of 8.3 GHz (2.6–10.9 GHz) is proposed. With the FSS, there is a 4–5 dBi improvement in the antenna peak gain and the back lobes are reduced by around 10 dBi. The measured and simulated results are in good agreement. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:314–319, 2015

CPW-Fed Monopole Antenna for Multiple System Integration

In this work, a coplanar-waveguide (CPW)-fed monopole antenna for multiple wireless communication system integration is developed. A rectangular monopole antenna and a feeding structure are fabricated on the same plane of the substrate to simplify circuit processing and position alignment. Simply tuning one of the CPW ground-plane widths, which results in an asymmetrical ground plane structure, enhances the impedance bandwidth and excites the circular polarization at 1.57 GHz. To cover the operation bandwidth of the wireless local area network (WLAN) system, a parasitic inverted-L radiating strip is shorted to the ground plane. The measured impedance bandwidth of a S11 <; -10 dB ranges from 1.37 to 2.82 GHz, and thus covers most commercial wireless communication systems, such as GPS, DCS, PCS, IMT-2000, WLAN, and LTE. The measured 3-dB axial-ratio bandwidth is about 3.8% with respect to 1.56 GHz.

DESIGN AND ANALYSIS OF TWO NOVEL CPW-FED DUAL BAND-NOTCHED UWB ANTENNAS WITH MODIFIED GROUND STRUCTURES

In this paper, two novel coplanar waveguide (CPW) fed printed ultra wide band (UWB) monopole antennas with dual band-notching characteristics are proposed. The modifled ground technique with symmetric ground plane in antenna 1 and asymmetric ground planes in antenna-2 is exploited to cover UWB application. Both antennas are compact with dimensions of 30£30£1:6mm 3 and have dual band-notched characteristics with flrst notched band for integrated band of WiMax 3.5/5.5GHz and C-band satellite communications 3.7{4.2GHz and second notched band for WLAN 5.2/5.8GHz bands. Antenna with symmetric ground plane achieves the impedance bandwidth of 2.9{11.5GHz, and antenna with asymmetric ground plane achieves the impedance bandwidth of 2.9{ 11.89GHz, respectively with VSWR < 2 except in the notched bands. The antennas are designed and optimized in CST Microwave Studio. The simulated VSWR of the proposed antenna designs is compared with the measured VSWR of fabricated antennas, and it is found that they are in a good agreement. Both antennas exhibit monopole-like radiation patterns with signiflcant gain in entire operating band. Maximum gain of the proposed antenna with symmetric ground plane is 5.3dBi at 8GHz, and that with asymmetric ground plane is 4.5dBi at 7GHz.

DESIGN OF COMPACT ASYMMETRIC COPLANAR STRIP-FED UWB ANTENNA WITH DUAL BAND-NOTCHED CHARACTERISTICS

In this paper, a new design of asymmetric coplanar strip (ACS)-fed UWB planar monopole antenna with dual band-notched characteristics is presented and investigated. The proposed antenna is composed of an asymmetric ground plane, a semi-circular radiator, together with two open-ended half wavelength bow-shaped slots etched on the radiation patch. This leads to the desired dual notched bands of 3.12{3.69GHz for WiMAX and 5.51{6.01GHz for WLAN. Experimental results show that the designed antenna, with compact size of 29:5 £ 12mm 2 , has stable and omnidirectional radiation pattern, sharp reduction in gain and group delay at notched frequencies. The very simple feeding structure and compact uniplanar design make it easy to be integrated within the portable device for UWB communication systems.

Design, Investigation and Measurement of A Compact Ultra Wideband Antenna for Portable Applications

The design of a printed compact planar antenna of asymmetrical structure with ultra wide bandwidth is described and investigated in this paper. The antenna provides more than 114% impedance bandwidth below VSWR 2 (from 3.3 to more than 12 GHz) with a center frequency of 7.65 GHz; thus it covers the bandwidth requirement for portable UWB wireless device applications. The structure of the asymmetric proposed antenna is very simple and composed of a small hexagonal shaped patch with two asymmetrical coplanar ground planes. It occupies an area of only 20 × 24.5 mm2 when printed on one side of an FR4 substrate with a thickness of 1.6 mm.

A Compact ACS‐FED Dual‐Band Meandered Monopole Antenna for Wlan and WiMax Applications

ABSTRACTIn this article, we present the design of a dual‐band (3.5 and 5.8 GHz), meandered monopole antenna for Wireless Local Area Network (WLAN)/Worldwide Interoperability for Microwave Access (WiMAX) applications, which is fed by an asymmetric coplanar strip (ACS). The proposed antenna is comprised of an asymmetric ground plane, an ACS‐fed structure, and coupled meandered monopole‐type of radiating elements that are designed to provide the two desired operation bands, namely 3.5 and 5.8 GHz. The two resonance frequencies of the antenna can be controlled by adjusting the dimensions of the radiating elements, namely the two meandered monopoles, and the gap between them which controls the coupling. The designed antenna has a small size, which is only 20 × 12 mm2 including the ground plane. Simulated and measured results are presented to demonstrate that the proposed dual‐band antenna is well suited for WLAN and WiMAX applications. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2370–2373, 2013

A Compact Asymmetric Coplanar Strip‐Fed Dual‐Band Antenna for 2.4/5.8 GHz Wlan Applications

ABSTRACTAn asymmetric coplanar strip (ACS)‐fed dual‐band antenna using loaded capacitance terminations for 2.4/5.8 GHz wireless local area network applications is studied numerically and verified experimentally. The proposed antenna consists of two meandered strip radiating elements, two loaded capacitance terminations, an asymmetric ground plane, a shunt inductor, and an ACS‐fed structure. Two resonance frequencies are controlled by adjusting the dimensions of the two meandered strip radiator elements and two loaded capacitance terminations. This antenna has small size of 17 × 12 mm2 including the ground plane. Simulation and measurement results show that the proposed antenna can work at dual‐band frequencies and has omnidirectional radiation patterns. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2066–2070, 2013

Compact super‐wideband asymmetric monopole antenna with dual‐branch feed for bandwidth enhancement

A novel compact super-wideband (SWB) antenna with an optimised feed is presented. The antenna is composed of an asymmetric trapezoid ground plane and a modified rectangular monopole patch. It is demonstrated that the bandwidth of the antenna is significantly enhanced by introducing an asymmetric dual-branch feed with an L-shaped feed branch. The measurements indicate that the 2:1 VSWR bandwidth is from 1.05 to 32.7 GHz with a ratio bandwidth of 31:1. Since the antenna features an extremely wide bandwidth and the entire size is only 74 × 80 mm, it is useful for modern wireless communication applications.

Modified Koch fractal antenna with asymmetrical ground plane for multi and UWB applications

In this paper the proposed structure is based on a modified planar Koch curve antenna, whose geometrical parameters are determined by iterative function system algorithm for fractal curve generation. Compared with conventional antenna with same dimensions, modified Koch curve antenna provides additional frequency resonances. The asymmetrical ground plane has been optimized by means of bacterial foraging optimization (BFO) to make the proposed antenna feasible for wide band operation. In addition to miniaturization of about 40%, the optimized reference ground plane provides multi and ultra-wide band with high impedance matching throughout the frequency bands covering various wireless telemedicine applications. In order to assess the reliability of the antenna, measurements have been performed on the fabricated prototype and the obtained results shows good agreement with simulated results.

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.

CPW-FED compact bent monopole antenna for UWB applications

A compact CPW-fed planar antenna suitable for ultra-wideband (UWB) applications is presented.The proposed design is a modification of the simple monopole antenna where the monopole is folded and the asymmetric ground plane dimensions are optimized for UWB performance. The simple geometry and its compactness make the antenna good candidate for portable applications involving integration with microwave monolithic integrated circuit (MMIC) devices. The antenna fabricated on FR4 substrate shows almost identical radiation characteristics in the entire band with an average gain of 2.5 dBi. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:56–58, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27252

Compact monopole antenna design for WLAN/WiMAX triple‐band operations

AbstractA novel design of a simple microstrip‐fed monopole antenna well suited to wireless local area network (WLAN)/worldwide interoperability for microwave access (WiMAX) application for triple‐band operation is proposed in this article. The proposed antenna consists of one branch strip, two hook‐shaped strips, an asymmetrical ground plane, and a rectangular slit in the ground plane. Through the proper selection of the dimensions as well as arrangement of the strips, desired resonant modes excited at 2.35/3.65/5.375 GHz with a less than −10‐dB input impedance frequency response can be achieved. Prototypes of the proposed antenna were fabricated and experimentally measured, and an acceptable agreement between the measurement and simulation results was achieved. The numerical and experimental results demonstrate that the proposed antenna satisfies the −10‐dB impedance bandwidth requirement while covering the WLAN and WiMAX bands simultaneously. Meanwhile, the 2D radiation patterns and 3D gain performance of the antenna in the operation bands were also observed and discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1838–1846, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26963

Compact monopole antenna with two strips and a rectangular‐slit ground plane for dual‐band WLAN/WiMAX applications

AbstractA novel design of a simple microstrip‐fed monopole antenna for wireless local‐area network/worldwide interoperability of microwave access (WLAN/WiMAX) band operation is proposed in this article. The proposed antenna consists of two branch strip, an asymmetrical ground plane, and a rectangular‐slit ground plane. The proposed antenna is capable of generating two separate resonant modes with good impedance‐matching conditions. Prototypes of the proposed antenna were fabricated and experimentally measured. Acceptable agreement between the measurement and simulation results was achieved. The numerical and experiment results demonstrate that the proposed antenna satisfies the return loss −10 dB (VSWR &lt; 1:2) impedance bandwidth requirement while simultaneously covering the WLAN and WiMAX bands. Meanwhile, the two‐dimensional radiation pattern and three‐dimensional gain performance of the antenna in the operation bands were also observed and discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1559–1566, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26875

Design of a microstrip-fed monopole antenna with a rectangular slit ground and a rectangular projection strip for dual-band WLAN operations

In this study, a novel dual-band planar monopole antenna for wireless local area network (WLAN) application was designed, fabricated, and measured.The proposed antenna was fabricated on a low-cost, easily available FR4 substrate, which effectively covers both the 2.4GHz and 5.2/5.8-GHz WLAN bands. The proposed antenna consists of two branches, an asymmetric ground plane, a rectangular projection strip, and a rectangular slit in the ground plane. The rectangular projection strip and the rectangular slit in the ground plane were introduced to enhance the performance of the proposed antenna. The obtained numerical results agree well with the experiment data. It was validated that the configuration can meet the demands of WLAN systems and effectively enhanced the impedance bandwidth to 39.7% for the lower band and 23.1% for the upper band when the impedance bandwidth was −10 dB. This article also presents and discusses the 2D radiation patterns and gains according to the results of the experiment that was conducted. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1039–1044, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26725

A compact Monopole Antenna Design for WLAN/WiMAX Triple Band Operations

In this study, a novel dual band planar monopole antenna for wireless local area network (WLAN)/ Worldwide Interoperability of Microwave Access (WiMAX) application was designed, fabricated, and measured. The proposed antenna consists of two hook shaped strips, an asymmetric ground plane, and a rectangular slit in the ground plane. Acceptable agreements between the measured and simulated results are achieved. Numerical and experimental results demonstrate that the proposed antenna satisfies the 10 dB impedance bandwidth requirement while covering the WLAN and WiMAX bands simultaneously. This paper also presents and discusses the 2D radiation patterns and 3D gains according to the results of the experiment that was conducted.