Dual-band WLAN Applications Research Articles

A quadrature LO-generator using an external single-ended clock receiver for dual-band WLAN applications

A quadrature LO-generator using an external single-ended clock receiver for dual-band WLAN applications

Flexible and Conformal Metamaterial based Microwave Absorber for WLAN, Wi-MAX and ISM Band Applications

ABSTRACT In this work, a flexible electromagnetic microwave absorber working in tri-band and dual band (i.e.) WLAN, Wi-Max and ISM applications are designed, fabricated, and characterised experimentally. The absorber consists of 9 × 9 array of rectangle and circular metamaterial structures with absorption rate above 90 and 80% respectively. The absorption response value varying with incident angle up to 60° in both TM and TE polarisation. The absorbers are designed and fabricated, and analyzed in both planar and conformal cases and observed that the rectangular metamaterial absorber having high absorption value when compared with circular metamaterial absorber. Prior to metamaterial characteristics of the absorber, the E-Field distributions, H-field distributions surface current distribution and return loss of both rectangular and circular metamaterial absorbers also evaluated. The proposed metamaterial absorber is tested using ANRITSU-MS2037C combinational analyser. The work demonstrates absorbers application to radar cross section reduction for WLAN, Wi-Max, and ISM applications.

Ultraminiaturised Polarisation Selective Surface (PSS) for dual‐band Wi‐Fi and WLAN shielding applications

This study reports on a highly miniaturised polarisation selective surface (PSS) for dual-band Wi-Fi and WLAN applications. The proposed unit cell consists of two independently tuneable square loops. The outer loop is split with a gap of 0.2 mm to introduce polarisation selectivity and miniaturisation for lower-frequency band of 2.5 GHz. The inner square loop is inductively loaded with arms to suppress 5.45 GHz frequency band. These configurations have resulted in a unit element size of at 2.5 GHz, which is not presented before to the best of the authors' knowledge. A wide rejection bandwidth () of more than 600 and 1180 MHz is obtained around 2.5 and 5.45 GHz, respectively. Furthermore, the proposed PSS exhibits an excellent polarisation selective characteristic by generating two stopbands at 2.5 and 5.45 GHz when illuminated by horizontal (TM) incident waves, whereas vertically (TE) polarised incident waves result in the generation of passbands for these two frequencies. Numerical validation through equivalent circuit modelling of the proposed PSS has also been carried out. A finite prototype containing elements is fabricated and tested. The measured results demonstrated that the PSS has excellent potential for applications that employ polarisation separators and wave generators.

Compact dual‐band filtering power divider with independently controllable bandwidths using shorted patch resonators

This study presents a novel dual-band filtering power divider (DB-FPD) structure with independently controllable bandwidths for dual-band application. The proposed DB-FPD structure is constructed by shorted G- and T-shaped patch resonators, and meandered slot lines are etched on shorted patch resonators to generate resonance in the upper band. The 3 dB fractional bandwidth (FBW) of designed DB-FPD structure in a lower band (upper band) can be adjusted from 5.2 to 24.2% (3.1 to 26.9%), respectively, using a substrate of 31 mil thick TLY-5. The even-/odd-mode method is adopted to demonstrate the power splitting and isolation performances. The lumped-element equivalent circuit is extracted to explain the power splitting transmission performance. Also, the coupling matrix analysis is applied to present the detailed design procedures for practical DB-FPD, with specific passband bandwidths and centre frequencies of dual passbands. Finally, the isolation performances are analysed with different isolation resistor values and loading positions. For verification, two DB-FPDs with equal absolute bandwidths (ABW) and equal FBWs are simulated, fabricated and measured for dual-band WLAN application. The measured results agree well with the simulated ones, exhibiting a favourable frequency selectivity and controllable passband bandwidths.

A Miniaturized and Polarization Insensitive FSS and CFSS for Dual Band WLAN Applications

This article reports on a dual band, polarization insensitive Frequency Selective Surface (FSS) for Wi-Fi and WLAN shielding applications. The design incorporates concentric square and circular loops loaded with log periodic directors and passion crosses, respectively. The proposed design is completely polarization insensitive. Also, the design has angular stability up-to 45° for both Transverse Electric (TE) and Transverse Magnetic (TM) polarizations. The FSS offers measured suppression of 38 dB at 2.4 GHz and 32 dB at 5.9 GHz. The detailed analysis of all parameters has been carried out. Equivalent lumped circuit model has also been proposed. The design is highly miniaturized with the unit element size of 0.1λ0 only. The complementary bandpass FSS has also been investigated. The measured results are in good agreement with the simulated response. The design has excellent potential for EM field suppression and security applications.

Design of Compact Dual-band Fractal Monopole Antenna with Virtually Extended Ground Plane

Achieving a particular response to serve multiple wireless applications is regarded as the primary demand in our modern age because of the considerable development of the communication devices. In this paper, a compact monopole antenna with reduced ground plane has been suggested to meet the requirements of the dual-band WLAN applications. The antenna miniaturization has been carried out in employing two techniques. Initially, the fractal geometry has been applied to the antenna radiating element. Two-sided Koch fractal curves up to the third iteration have been used to increase the path of electrical current on the surface of the radiating element which is in the form of a square with dimensions. To gain more miniaturization, the antenna ground plane has been further reduced by using different lengths of two open-ended parallel stubs to form a virtually extended ground plane. This supportive technique has been adopted as a tuning means to control the path of the electrical currents exciting the resulting resonances. The proposed antenna and has been printed on an FR-4 substrate with a thickness of 1.6 mm and 4.4 relative dielectric constant and is fed by 50-ohm microstrip feed line. The resulting antenna dimensions are of about 19.1 mm × 19.1 mm. A parametric study has been carried out, and the results reveal that the proposed antenna offers a dual-band performance with a considerable ratio of resonant frequencies covering the existing 2.4/5.2/5.8 GHz WLAN applications, besides many other communication services.

WLAN 시스템에 적용 가능한 삼중 폴디드 패치를 가진 CPW 급전 소형 안테나

본 논문에서는 WLAN 시스템에 적용 가능한 이중 대역을 갖는 삼중 폴디드 형태의 CPW 급전 방식의 소형 안테나를 제안하였다. 기존 이중 역-L형 안테나를 ㄷ자 형의 패치와 이중 역-L형 안테나로 변경하여 안테나의 소형화에 따른 협대역 특성을 극복하였으며, <TEX>$16.5mm{\times}29.5mm{\times}1.0mm$</TEX>의 크기로 2.4 GHz 대역과 5 GHz 대역에서 사용할 수 있도록 최적화하여 설계 및 제작하였다. 두께 1.0 mm의 FR-4 기판으로 제작하였으며, 측정한 결과 이중 대역에서 -10 dB 이하의 반사 손실 값을 얻어 이중 대역 WLAN 시스템용 안테나로서 사용할 수 있음을 확인하였다. In this paper, the compact CPW-fed antenna with triple folded patch for dual-band WLAN applications is proposed. As the conventional double inverted-L antenna is changed into the C-shaped patch and double inverted-L antenna, the antenna overcomes the narrow-band characteristics according to the miniaturization of the antenna. The proposed antenna with the size of only <TEX>$16.5mm{\times}29.5mm{\times}1.0mm$</TEX> is designed and fabricated by optimized parameters to be operated at 2.4 GHz band and 5 GHz band. The antenna is fabricated into FR-4 substrate with thickness of 1.0 mm. We confirm that it is operated as antenna for WLAN applications by obtaining the measured return loss level of < -10 dB at dual-band.

A Printed Monopole Antenna with a Protruding Stub in the Ground Plane for Dual Band WLAN and RFID Applications

A Printed Monopole Antenna with a Protruding Stub in the Ground Plane for Dual Band WLAN and RFID Applications

A STACKED EQUILATERAL TRIANGULAR PATCH ANTENNA WITH SIERPINSKI GASKET FRACTAL FOR WLAN APPLICATIONS

In present work, a microstrip Sierpinski modifled and fractalized antenna using multilayer structure to achieve dual band behavior for WLAN applications has been proposed. Due to the space-fllling properties of fractal geometry, the proposed antenna is smaller in size than the conventional Euclidean-type. An equilateral triangular patch antenna with Sierpinski Gasket fractal shape has been designed and studied. An electromagnetic coupled stacked structure of two difierent patches operating at two frequencies (2.4GHz Bluetooth and 5.8GHz Wireless LAN) has been designed for dual band WLAN applications.

A COMPACT DUAL INVERTED C-SHAPED SLOTS ANTENNA FOR WLAN APPLICATIONS

A novel design of a compact dual inverted C-shaped slots antenna for dual-band (IEEE 802.11b/g, 2.4{2.484GHz and IEEE 802.11a, 5.15{5.35/5.725{5.825GHz) WLAN applications is proposed in this paper. The antenna is based on dual inverted C-shaped slots and a -shaped feeding structure. These fundamental conflgurations are applied to achieve two operating bands with resonating frequencies at about 2.45GHz and 5.5GHz to cover the dual WLAN bands. The proposed antenna is fabricated and tested. The simulated and measured results show that the slot antenna obtains two independent operation bands of 2.4{2.515GHz and 5.14{5.85GHz for S11 • i10dB, and also stable gain characteristic with peak gain variations less than 1dBi for both the bands. Details of the analysis and research progresses are shown in the following sections to illustrate the design steps and the performance of the proposed antenna.

Reconfigurable dual-band C-shaped monopole antenna array with high isolation

A reconfigurable dual-band monopole array with high isolation for WLAN MIMO application is proposed. This antenna array contains two C-shaped monopoles with a shorting line, on which two RF switches were integrated, connecting the two antenna elements that are separated by a distance of 0.09Λ 2.4GHz . High isolation at 2.4 or 5.2 GHz bands can be achieved by changing the states of the RF switches. Experiment results indicate that the proposed antenna array has a - 10 dB bandwidth that covers the required frequencies for dual-band WLAN applications with an isolation higher than 20 dB over the lower operation bands when the RF switches are 'ON', and an isolation higher than 17 dB at the higher operation band when the switches are 'OFF'.

A WIDE OPEN U-SLOT ANTENNA WITH A PAIR OF SYMMETRICAL L-STRIPS FOR WLAN APPLICATIONS

A wide open slot antenna with a pair of symmetrical L- strips for dual-band WLAN applications is proposed in this paper. A T-shaped monopole is used to cover 5:15 » 5:825GHz. To achieve dual-band characteristic, a pair of symmetrical L-strips is embedded in the wide open U-slot to generate another band covering 2:4 » 2:48GHz. The two bands are relatively independent from each other. The proposed antenna has the advantages of simple structure and excellent performance on the WLAN 2.4/5.2/5.8GHz bands. The measured results of the fabricated antenna show that the impedance bandwidths are 150MHz from 2.37 to 2.52GHz and 1270MHz from 4.83 to 6.10GHz, which cover all the desired operating bands. Furthermore, the antenna design and some signiflcant parametric studies are also described in detail.

Compact CPW-fed dual-band antenna

A novel coplanar waveguide (CPW) antenna is proposed for dual-band WLAN applications. It comprises a rectangular patch, a rectangular notch cut at the lower edge of the patch and a CPW transmission line. The rectangular patch together with the ground plane of the coplanar waveguide radiates at the lower frequency band, 2.4 GHz for IEEE802.11b/g, while the rectangular notch resonates in the upper band, 5.2/5.8 GHz for IEEE 802.11a. The designed antenna is only 32×5 mm, which can provide stable omnidirectional radiation patterns with an average gain of 2 dBi in both the bands. The antenna is very compact and suitable for 2.4 and 5.2/5.8 GHz WLAN operations.

ACS fed printed F‐shaped uniplanar antenna for dual band WLAN applications

AbstractAn asymmetric coplanar strip (ACS) fed dual band F‐shaped antenna covering the 2.4/5.2 GHz WLAN bands is presented. The optimized dimensions of the proposed uniplanar antenna are 21 mm × 19 mm when printed on a substrate of dielectric constant 4.4 and height 1.6 mm. The dual band nature of the antenna is brought about by the various current paths in the F‐shaped structure and the ground plane. The antenna exhibits nearly omnidirectional radiation characteristics and moderate gain in both the operating bands. Details of the antenna design, simulation, and experimental results are presented and discussed. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1852–1856, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24486

Parametric analysis of Sierpinski‐like fractal patch antenna for compact and dual band WLAN applications

AbstractA Sierpinski‐like fractal patch antenna with a slant strip in the first iteration is proposed in this article. The parameters of this kind of antenna are analyzed and optimized for dual WLAN application. The added slant strip provides simple probe feeding for compactness and also helps bandwidth enhancement due to multiple modes, which can be evident from current distribution. Measured return loss below −10 dB is from 2.38–2.45 GHz and 5.17–5.83 GHz, coinciding well with dual band WLAN standard. The boresight gain and radiation pattern in different planes are also presented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 36–40, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23974

Circular Axe-Shaped Patch Antenna for Compact and Dual Band Wireless Applications

A compact circular AXE-shaped patch antenna is presented for miniaturized application. The proposed design is further modified for dual band 2.4/5.5 GHz wireless application. The measured return loss is from 2.38∼2.42 GHz and 5.41∼5.59 GHz suitable for dual band WLAN application. Same design procedure can also be applied for miniaturized applications. The miniaturization process shifts the resonance at 1.71 GHz instead of 2.5 GHz in case of simple circular patch. The radiation pattern and gain for dual band wireless antenna is also measured and presented.

A Microstrip Fed Monopole Patch Antenna with three Stubs for Dual-band WLAN Applications

A microstrip fed dual-band design of monopole patch antenna with three stubs is presented in this paper. Printed on a dielectric substrate and fed by a 50 Ω microstrip line, a rectangular patch antenna with 3 stubs is demonstrated to generate two separate resonant modes to cover 2.4/5.2/5.8 GHz (wireless local area network) WLAN bands with satisfactory radiation properties. The impedance bandwidth of the proposed antenna is 400 MHz at 2.4 GHz band (2250–2650 MHz, 16.3%) and 920 MHz at 5 GHz band (4990–5910 MHz, 16.9%). The performances of this antenna are highly desirable for 2.4 and 5 GHz dual-band WLAN applications. The parameters which affect the performance of the antenna in terms of its frequency domain characteristics are investigated in this paper.

A Novel Planar Monopole Antenna with an H-shaped Ground Plane for Dual-band Wlan Applications

A novel dual-band design of planar monopole antenna is presented in this paper. Printed on a dielectric substrate and fed by a 50 Ω microstrip line, a planar monopole antenna is demonstrated to generate two separate resonant modes to cover 2.4/5.2 GHz WLAN (wireless local area network) bands with satisfactory radiation properties. The impedance bandwidths of the proposed antenna are 600 MHz centered at 2.65Hz and 1.15GHz centered at 5.12 GHz for S 11 < −10 dB. The parameters which affect the performance of the antenna in terms of its frequency domain characteristics are investigated.

A new printed G‐shaped monopole antenna for dual‐band WLAN applications

AbstractA novel dual‐band printed G‐shaped monopole antenna is proposed. The antenna provides two resonant paths of different lengths (forming into a G‐shaped profile) in order to achieve 2.4‐ and 5.2‐GHz dual‐band operation for WLAN applications. Reasonably large impedance‐matching bandwidth and good radiation patterns have been observed. The measured impedance bandwidth for 10‐dB return loss in the 2.4‐ and 5.2‐GHz bands reaches 0.37 GHz (2.25–2.62 GHz) and 1.06 GHz (4.94–6 GHz), respectively. In addition, the proposed antenna has a small size of 13.6 × 9.3 mm2. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 295–297, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20800

Printed crisscross monopole antenna with a square conductor-backed parasitic plane for dual-band WLAN applications

In this paper, we demonstrate a new and simple dual-band design of a printed monopole antenna. The antenna consists of a crisscross monopole element with a microstrip feedline and a conductor-backed parasitic plane. The crisscross monopole and the conductor-backed parasitic plane are designed to achieve 2.4- and 5.2-GHz dual-band operations for WLAN applications. The measured impedance bandwidth for 10-dB return loss is from 1.72 to 2.87 GHz and 4.41 to 6.09 GHz, covering the 2.4- and 5.2-GHz WLAN standards. The measured radiation patterns exhibit typical monopole-antenna radiation characteristics. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 541–543, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21042