GHz Wireless Local Area Network Research Articles

Dual-Band Meander Monopole Antenna for WLAN Operation in Laptop Computer

A very small-size (10 × 6 × 0.4 mm ) uniplanar meandered monopole antenna that is fed by a 50-Ω mini-coaxial cable for laptop computer applications is proposed. To achieve dual-band 2.4/5-GHz wireless local area network (WLAN) operation, a protruded tuning stub is introduced into the meandered monopole structure. The achieved 10-dB bandwidths of the lower and upper operating bands in free-space condition are 12% (2360-2660 MHz) and 20% (4870-5960 MHz), respectively. Further experimental studies are also conducted by mounting the proposed antenna onto an actual laptop computer that works as the host platform.

Design of co-axial fed broadband single layer rectangular microstrip patch antenna for wireless applications

In present work, a novel co-axial fed single layer E-shaped rectangular micro strip patch antenna with broadband behavior for wireless local area network (WLAN) and world-wide interoperability for microwave access (Wi-MAX) applications is proposed. The micro strip antenna has a planar geometry that consists of a ground, a substrate, a patch, and a feed. The basic theory about the proposed structural design, impedance matching, and the radiation characteristics are studied and analyzed using method of finite difference time domain technique. Simulation was conducted using computer simulation technology microwave studio software for optimization of antenna's properties. The proposed antenna has a frequency bandwidth of about 712 MHz (5.16-5.88 GHz) at −10 dB return loss which is sufficient to make the antenna useful for 5.2/5.8 GHz WLAN and 5.5 GHz Wi-MAX application. The WLAN standard requires the antenna to cover 5.15-5.35 GHz and 5.725-5.825 GHz frequency bands and Wi-MAX requires the antenna to cover 5.25-5.85 GHz frequency band. Maximum achievable gain over the entire frequency band is 5.5 dBi. To meet the demanding bandwidth specification, a substrate of low dielectric constant is selected to obtain a compact radiating structure. Furthermore, reflection coefficient is below −10 dB over the entire frequency band at the input of the optimized E-shaped micro strip patch antenna with 50-Ω system impedance.

CO-DESIGN OF A COMPACT DUAL-BAND FILTER-ANTENNA FOR WLAN APPLICATION

A co-designed compact dual-band fllter-antenna suitable to be embedded inside a wireless access point (AP) in the 2.45/5.2- GHz wireless local area network (WLAN) bands is presented. The proposed fllter-antenna comprises a loop-loaded dual-band monopole radiator and a microstrip dual-band pseudo-interdigital bandpass fllter. The monopole consists of a uniform width monopole, two identical capacitively loaded magnetic resonators and a top loaded loop. The two magnetic resonators are loaded at the center of the monopole for dual-band operation and the rectangular loop loaded at the top is involved for miniaturization. Instead of using the traditional 50› interfaces, the impedance between the fllter and antenna is optimized to improve the performance. The fllter-antenna and the system circuit board of an AP share the same substrate and ground plane. In this case, the design can fully integrate the circuit board of the AP into an internal fllter-antenna solution. The proposed fllter-antenna provides good selectivity and rejection in out of band regions and omni-directional radiation patterns within the two desired bands. The measured results show good agreement with the simulated ones.

Dual band‐notched small monopole antenna with novel W‐shaped conductor backed‐plane and novel T‐shaped slot for UWB applications

In this study, a novel method for designing a new monopole antenna with dual band-notched characteristic for UWB applications has been presented. The proposed antenna consists of a square radiating patch with a modified T-shaped slot, and a ground plane with two E-shaped slots and a W-shaped conductor backed-plane. By cutting two E-shaped slots in the ground plane, additional resonance is excited and hence much wider impedance bandwidth can be produced, especially at the higher band, which results in a wide usable fractional bandwidth of more than 130% (2.73%13.3 GHz). In order to generate single band-notched characteristic, the authors use a W-shaped conductor backed-plane structure on the other side of the substrate. In addition, by cutting a modified T-shaped slot in the radiating patch and microstrip feed-line, a dual band-notched function is achieved. The measured results reveal that the presented dual notch band monopole antenna offers a very wide bandwidth with two notched bands, covering all the 5.2/5.8 GHz wireless local area network, 3.5/5.5 GHz WiMAX and 4 GHz C bands. The designed antenna has a small size of 12 % 18 mm 2 . Good voltage standing wave ratio (VSWR) and radiation pattern characteristics are obtained in the frequency band of interest. Simulated and measured results are presented to validate the usefulness of the proposed antenna structure for ultra-wideband (UWB) applications.

Rectangular Ring Open-Ended Monopole Antenna with Inverted L-Strip for WLAN Dual-Band Operations

A novel design for a simple rectangular ring with open-ended monopole antenna wireless local area network (WLAN) applications is proposed in this article. The proposed antenna consists of an open-ended rectangular ring, an inverted L-strip, and a rectangular slit in the ground plane, and is fed by a 50 <TEX>${\Omega}$</TEX> microstrip feed-line. Prototypes of the proposed antenna were designed, fabricated, and tested. Experimental results show that the proposed antenna receives 2.3125-2.775 GHz and 4.8625-6.7125 GHz with a return loss less than -10 dB, covering the required bandwidths of the 2.4/5.2/5.8 GHz WLAN standards. Meanwhile, the 2D radiation patterns and 3D gain performance of the antenna in the operation bands were also observed and discussed.

Printed parallelogram monopole antenna with symmetrical parasitic elements for wideband applications

A printed microstripline-fed parallelogram monopole antenna for wideband applications is presented.This antenna is composed of a parallelogram monopole, a ground plane with three symmetrical parasitic elements, and a 50-Ω microstrip feedline. By using short-circuited parasitic elements including a symmetrical parallelogram patch and a pairs of strip lines, the proposed antenna can excite extra resonate modes to achieve wideband operation. The measured results show that the proposed antenna offers a large impedance bandwidth for 10-dB return loss is 4.74 GHz (1.82–6.56 GHz), corresponds to fractional bandwidth of 113% for central frequency at 4.19 GHz, and can cover the personal communication services, IMT-2000, 2.4/5.2/5.8 GHz wireless local area network, and 2.5/3.5/5.5 GHz worldwide interoperability for microwave access standards. In addition, measured radiation patterns exhibit reasonable radiation characteristics. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:388–391, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27278

CRLH-TL을 이용한 2.45GHz 무선랜용 ZOR 안테나 설계

본 논문은 CRLH-TL(composite right left handed transmission line) 메타물질을 이용하여 2.45GHz 무선랜용 ZOR(zeroth order resonance) 안테나를 설계하는 것이다. 일반적으로 안테나는 파장에 대비한 선로의 길이에 따라 공진주파수가 결정되지만 ZOR 안테나는 파장의 길이와 상관없이 안테나의 공진주파수를 결정한다. 그러므로 소형화 할 수 있는 장점이 있으며 방사패턴 또한 등방성의 방사패턴을 가지는 장점이 있다. ZOR 안테나를 설계하기 위해 먼저 단위 셀 길이를 <TEX>${\lambda}/4$</TEX>의 길이보다 작도록 조정하여 균질한 매질 특성을 가질 수 있도록 하였다. 제안된 안테나는 공진 주파수의 감소와 대역폭의 증가를 위하여 CPW 급전을 사용하였고, 기존의 mush-room 형태의 CRLH-TL 보다 높은 인덕턴스와 낮은 캐패시턴스를 얻기 위하여 방사패치와 접지면 사이에 단락 스터브가 사용 되었다. ZOR(zeroth order resonance) antenna for 2.45GHz WLAN(wireless local area network) is designed by use of CRLH-TL(composite right left handed transmission line) meta-material. The electrical length of conventional antennas is determined generally according to the resonant frequency, whereas that of ZOR antenna can be determined without reference to the resonant frequency. Therefore ZOR antenna has advantage in miniaturization of antenna in comparison with conventional antennas. In order to design such ZOR antenna, first unit cell with electrical length shorter than a quarter wavelength at 2.45GHz is designed to the some characteristics of homogeneous medium. In order to decrease resonant frequency and enhance frequency bandwidth, the proposed antenna is fed by CPW(co-planar waveguide) and short stub between radiation patch and ground plane is used for obtaining both higher inductance and smaller capacitance than previous mush-room type of CRLH-TL.

Dual band-notch square monopole antenna with a modified ground plane for UWB applications

This paper presents a novel small square monopole antenna for UWB applications with dual band-notch function. By cutting an S-shaped slot in the ground plane, additional resonance is excited and hence, much wider impedance bandwidth can be produced, especially at the higher band that provides a wide usable fractional bandwidth of more than 120% (2.98–12.25 GHz). To generate a single frequency band-stop performance, we add a pair of C-shaped parasitic structures in the ground plane, and also in order to create the second notch frequency, we insert a horizontal rectangular strip in the center of two C-shaped parasitic structure in the ground plane. The measured results reveal that the presented dual band-notch monopole antenna offers a wide bandwidth with two notched bands, covering all the 5.2/5.8 GHz wireless local area network, 3.5/5.5 GHz WiMAX, and 4 GHz C bands. Good and radiation behavior within the UWB frequency range have also been obtained. The antenna has a small dimension of 12 × 18 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2743–2747, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27209

Compact meander T-shaped monopole antenna for dual-band WLAN applications

A compact coplanar waveguide-feed monopole antenna with dual-band characteristics is proposed in this article. The proposed antenna mainly consists of meander T-shaped monopole and small ground plane embedded with a pair of L-shaped couple slots and two pairs of I-shaped notched slots symmetrically. By elongating the meander T-shaped arms and carefully selecting the positions and lengths of L-shaped slot and I-shaped slot, the antenna excites four resonant frequencies at 2.42, 2.52, 4.75, and 5.54 GHz which are formed into two wide bands to cover all the 2.4/5.2/5.8 GHz wireless local area network (WLAN) operating bands, and is with miniaturization structure. Moreover, the antenna can provide nearly dipole-like radiation patterns and good gains across the dual operating bands. These results prove that the proposed dual-band antenna is very suitable for WLAN applications. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013. © 2013 Wiley Periodicals, Inc.

A Novel Microstrip-Fed Monopole Antenna For WLAN/WiMAX Applications

A new microstrip-fed printed monopole antenna which is simple in design and compact in size is presented for simultaneously satisfying wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) bands. A simulation software package, CST Microwave Studio, has been used to model the proposed antenna, whose electrical characteristics and radiation performance are thoroughly analyzed as well. The proposed antenna, with small size of 28 × 51 mm2 on Rogers RT/Duroid® 5870 substrate with permittivity 2.33, was designed and fabricated. It was demonstrated that the measured 10 dB bandwidth for return loss is from 1.76 to 2.59 GHz, 3.44 to 3.89 GHz and 5.18 to 5.99 GHz, covering all the 2.4/5.2/5.8 GHz WLAN and 2.5/3.5/5.5 GHz WiMAX bands.

Novel radiation pattern reconfigurable antenna with six beam choices

This article presents a novel radiation pattern reconfigurable antenna with six beam choices, which works in 5.2 GHz wireless local area network (WLAN) frequency band. The designed antenna has good impedance matching at the resonant frequency. The beam can be reconfigured to six different directions, and each main lobe of six azimuth patterns has a half power beam width (HPBW) of about 60°. The antenna can cover all directions in the azimuth plane (XY-plane) by controlling the states (ON or OFF) of six switches. Simulation and measurement have been carried out to validate the design and experimental results demonstrate that the proposed antenna has the capacity to provide the pattern reconfigurability.

A dual‐wideband antenna with an open L‐slot for WLAN/WiMAX applications

AbstractA dual‐wideband antenna with an open L‐slot for wireless local area network (WLAN)/worldwide interoperability for microwave access (WiMAX) applications is proposed.A rectangular radiator with an open L‐slot etched on the ground is used to cover 2.4∼3.69 GHz. To achieve dual‐band characteristic, a rectangular strip is inserted on the rectangular radiator horizontally to generate another band covering 5.15∼ 5.85 GHz. The two bands are relatively independent with each other. Experimental results show that the antenna can operate at two separate impedance bands (S11&lt;−10 dB) of 1330 MHz (2.37∼ 3.70 GHz) and 1140 MHz (4.95∼ 6.09 GHz), which can cover all the 2.4/5.2/5.8 GHz WLAN bands and the 2.5/3.5/5.5 WiMAX bands. Detailed design steps and experimental results are studied and investigated in this article. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1499–1502, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26852

Design and analysis of slot antenna with band notch function

In this article, the design, simulation, and construction of a novel wide rectangular slot antenna fed by a 50 Ω coplanar waveguide (CPW) are presented and investigated for multifunctional communication systems. The physical dimension of the antenna is 29 mm (length) × 32 mm (width) × 1.6 mm (thickness). Detailed simulations and experimental investigations are performed to understand its behavior and to optimize for 2.4 GHz wireless local area network (WLAN) and ultra wideband (UWB) operations. The proposed slot antenna is etched on an FR4 substrate with a thickness of 1.6 mm and relative permittivity of 4.4. To improve the impedance matching, a stepped stub structure with CPW feed technique is used. According to the measured results, the proposed antenna has a large bandwidth from 2.1 to 11.6 GHz for voltage standing wave ratio (VSWR) less than 2, totally satisfying the requirement of 2.4 GHz WLAN and UWB systems, while providing the required band notch function from 5.1 to 5.9 GHz. The study of time domain characteristics and surface current distributions also indicate the band-notched function of the antenna. The radiation patterns display nearly omnidirectional performance and the antenna gain is stable except for the rejected frequency band (5.1–5.9 GHz). Moreover, group delays are within 1.5 ns except for the notch-band. It is observed that the simulated and experimental results have good agreement with each other. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.

Integration of loop and slot antennas into one-piece metal plate for concurrent 2.4- and 5-GHz wireless local area network operation

A compact, one-piece, metal-plate, multiple antenna system capable of generating concurrent 2.4- and 5-GHz bands with directional radiation patterns for wireless local area network (WLAN) applications is presented.The design is obtained by integrating two loop and two slot antennas arranged sequentially along a rectangular antenna ground into a single flat plate with overall size of 3 × 75 × 75 mm3. The ground plane in this design not only acts like a reflector for the 2.4 GHz loops but also provides the 5 GHz slots an efficient finite ground to properly excite the antenna. With a simple structure, compact size, and good radiation characteristics, the antenna is easy to fabricate and suitable for applications in WLAN access points. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:815–820, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26624

A multiband antenna array for WLAN/WiMAX applications

In this article, we proposed an antenna array with multiband for wireless local area network (WLAN)/WiMAX applications. The operating frequency band of the antenna covers the 2.4/5.2/5.8 GHz WLAN (2400–2484/5150–5350/5725–5875 MHz), and the 2.5/3.5/4.3/5.5 GHz/7.5 GHz WiMAX (2500–2690/3300–3800/4300–4990/5250–5850/6720–7790 MHz). This antenna has advantage of its simple configuration, low profile, compactness, and low fabrication cost. Microwave experiments and numerical simulations are performed to demonstrate its functionalities. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:664–667, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26598

A Wearable Dual-Band Dielectric Patch Antenna for LTE and WLAN

In this paper, a dual-band microstrip patch array antenna for both the Multiple Input Multiple Output (MIMO) 4G Long-Term Evolution (LTE) and the Wireless Local Area Network (WLAN) systems is developed. Design simulation and optimization processes are carried out with the aid of the Advanced Design System (ADS) electromagnetic simula-tor that uses the full–wave Method of Moment (MoM) numerical technique [1]. Rectangular microstrip patch antenna constructed from Multi-Walled Carbon Nanotubes (MWCNT) ink with electrical conductivity of 2.2 × 104 S/m and relative permittivity of 5-j1 is used as the conductor patch [2]. The patch is deposited on Rogers substrate RT-Durid 5880 single substrate with (εr = 2.2) and thickness of 62 mil. U-shape slot is used to provide the dual-band. The pro-posed antenna operates at 3.5 GHz for LTE and 5 GHz for WLAN. The proposed antenna parameters are compared with published result of copper patch [3,4] for the same application. Great enhancement in antenna size, matching, and frequency band width are achieved for the proposed antenna at the expense of gain and antenna efficiency compared with copper one. The proposed MWCNT dielectric antenna size is 18.4 mm × 27 mm compared with size of 27 mm × 37 mm for copper one respectively. The gain is better than 7dBi with antenna efficiency of 87.29% at 3.5GHz for cop-per patch antenna and is better than 1.692 dBi with antenna efficiency of 27.05% at 3.5GHz for MWCNT respectively.

Patch microstrip antenna with improving radiation performance for 2.4-GHz WLAN access point

A patch microstrip antenna with an inverted- V ground plane capable of improving radiation performance for a wireless local area network (WLAN) access point in the 2.4-GHz band is presented. By using a feeding structure composed of a step-shaped feeding strip in the air substrate and a coplanar strip in the narrow radiating patch, the proposed antenna can reduce cross-polarisation radiation (less than -20-dB) for frequencies across the 2.4-GHz WLAN band. The inverted- V ground plane comprises a narrow central ground portion for setting the 50 subminiature version (SMA) connector for the patch antenna and two bent ground portions to control the broadening of the antenna s horizontal radiation pattern. By selecting the proper dimensions, the proposed antenna can have a wide horizontal radiation pattern of about 152 (3 dB beamwidth) with vertical polarisation, which is very suitable for WLAN access-point applications where uniform radiation in one direction or one half-space is required. Experimental results of a constructed prototype suitable for application in the 2.4 GHz WLAN access point are presented and discussed.

MINIATURE TRIPLE-BAND CPW-FED MONOPOLE ANTENNA FOR WLAN/WIMAX APPLICATIONS

A miniature single-layer CPW-fed monopole antenna with triple-band operation for wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications is presented. The proposed antenna, comprising a planar rectangular patch element embedded with dual U-shaped slot, is capable of generating three distinct operating bands, 2.37{2.53, 3.34{ 3.82, and 4.23{6.88GHz covering all the 2.4/5.5/5.8GHz WLAN bands and the 3.5/5.5GHz WiMAX bands. The designed antenna has a simple uniplanar structure and occupies a small size of 25 £ 18mm 2 including the flnite ground CPW feeding mechanism. Moreover, the proposed antenna shows good monopole-like radiation patterns with small cross-polarization and stable antenna gains across the three operating bands.

Ultra‐wideband small square monopole antenna with dual band‐notched function

AbstractA dual band‐notched printed ultra‐wideband monopole antenna is presented, with a modified radiating patch.To generate single and dual band‐notched characteristics, we use two rectangular slots. By properly adjusting the dimensions of these slots two controllable notch resonances are achieved, but also the lower edge frequency of the band is decreased. The measured results show that the proposed dual band‐notched monopole antenna offers a wide bandwidth from 2.5 to 11 GHz, with two notched bands, covering all the 5.2/5.8 GHz wireless local area network, 3.5/5.5‐GHz WiMAX and 4‐GHz C bands. The designed antenna has a small size of 12 × 18 mm2. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:372–374, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26571

Low-power and high-linearity SiGe HBT low-noise amplifier using IM3 cancellation technique

In order to achieve high linearity and low noise figure (NF) simultaneously, a modified cascode structure with a series-shunt feedback capacitance achieving third-order intermodulation (IM3) cancellation is proposed. The proposed LNA is designed and simulated for 5.7GHz wireless local area network (WLAN) band applications with a [email protected] silicon germanium (SiGe) bipolar-CMOS (BiCMOS) process. The LNA has the power gain of 16.25dB, NF of 2.79dB, IIP3 of 3.69dBm with 4mW DC power consumption from a supply voltage of 3V. To our knowledge, by comparison with recently reported LNAs, the presented LNA achieves the highest figure of merit (FOM) by taking into account the power gain, IIP3, NF, power consumption, and operation frequency.