Branch Strips Research Articles

Sub-6GHz 4G/5G Conformal Glasses Antennas

The difficulty of antenna design applied to glasses is that the structure of glasses is too single, and the space available for antenna design is greatly limited. In this background, the integrated design of 4G antennas and 5G antennas applied to glasses is proposed in this paper. The most important highlight of this design is that it makes full use of the limited three-dimensional space structure provided by glasses and achieves the perfect combination of the antenna and glasses in the physical structure. Specifically, two antennas for 4G communication are arranged on two glasses frames, and four antennas for 5G communication are arranged on two glasses legs. In this way, we can make full use of the space provided by the glasses to design antennas and ensure that there is a certain distance between the 4G antennas and 5G antennas so that the performance of both 4G antennas and 5G antennas can be guaranteed. The 4G antenna consists of a loop structure printed on the frame and leg of the glasses and a parasitic branch strip printed on the front of the leg of the glasses. The resonance modes of the 4G antenna are mainly loop, monopole, and dipole modes, which can cover two 4G bands of 0.824-0.96 GHz and 1.71-2.69 GHz. Each 5G antenna mainly comes from the open slot mode etched on the metal ground surface of an FR4 substrate of the glasses leg. In addition, the slot antennas operate in two 5G bands of 3.3-3.6 GHz and 4.8-5.0 GHz. Finally, the glasses and the antennas are fabricated based on FR4 substrates and measured. The measured results show that the proposed antennas perform well and have the potential to be used in 4G/5G communications through glasses.

A miniaturized triple band monopole antenna with a coupled branch strip for bandwidth enhancement for IoT applications

AbstractA miniaturized monopole antenna with multiband operations for LTE, WWAN, WiMAX, and WLAN applications is presented. The antenna consists of multibranch strips and is fabricated on both sides of the FR4 substrate, which has a compact size of 10(L) ×10(W) ×0.8(T) mm3 to be embedded inside the Internet of Things (IoT) device as an internal antenna. Three operating bands covering 2.3–2.69, 3.4–3.7, and 5.15–5.85 GHz for the LTE, WWAN, WiMAX (2.3/2.5/3.5 GHz), and WLAN (2.4 GHz) systems are achieved with good radiation efficiencies. The proposed antenna can be embedded in the IoT device for the LTE, WWAN, WiMAX, and WLAN applications. The proposed antenna has advantages of sided structure, easy fabrication, low cost, and multiband operation. Also, the impedance matching performance of 3 resonant modes for the antenna can be adjusted flexibly. This makes the proposed antenna design suitable for practical applications. Details of the design process and the experimental results of the constructed antenna are presented.

ACS-Fed e-Shaped Dual Band Uniplanar Printed Antenna for Modern Wireless Communication Applications

A printed small size (12×16.5 mm) ACS-fed e-shaped uniplanar antenna is proposed for dual band applications. The multiband operating characteristics have been achieved by integrating e-shaped radiating strips to the 50ΩACSfeed line. Two simultaneously operating wide bands have been generated by using optimized radiating branch strips for the multiband applications. For obtaining size reduction and wider impedance bandwidth, e-shaped meandered elements are chosen in the design. The proposed design features the bandwidth (VSWR < 2, reflection coefficient below–10 dB) of 100 MHz in 2.4–2.5 GHz, and 2100MHzin 4.0–6.1 GHz. The developed multiband antenna can be useful for several wireless communication applications, such as 2.4 GHz Bluetooth/RFID,WLAN(2.4/5.2/5.8 GHz), WiMAX (5.5 GHz), US public safety band (4.9 GHz), ISM band, radio frequency energy harvesting and internet of things (IoT) applications.

WLAN 적용을 위한 두 개의 분기 선로를 갖는 CPW 급전 모노폴 안테나의 설계와 제작

In this paper, a CPW-fed dual-band monopole antenna with two branch strips for WLAN(Wireless Local Area Networks) applications was designed, fabricated and measured. The proposed antenna is based on a CPW-feeding structure, and composed of two branch strips and then designed and tuned the length of two branch lines to obtained required frequencies bands. To obtain the optimized parameters, we used the simulator, Ansoft’s High Frequency Structure Simulator(HFSS) and carried out simulation about parameters L5, L8, W3, W5, W9. The proposed antenna is fabricated on the FR-4 substrate using the obtained parameters. The numerical and experiment results demonstrated that the proposed antenna obtained the -10 dB impedance bandwidth 1,095 MHz (1.57∼2.665 GHz) for 2.4 GHz band and 1,680 MHz (4.99∼6.67 GHz) for 5 GHz band satisfied requirement while simultaneously covering the WLAN bands. And characteristics of gain and radiation patterns are determined for WLAN operating bands.

Triple‐band CPW‐fed monopole antenna with three branch strips for WLAN/WiMAX triple‐band application

ABSTRACTIn this article, a novel coplanar waveguide (CPW)‐fed monopole antenna with three branch strips for wireless local area network (WLAN)/worldwide interoperability of microwave access (WiMAX) triple‐band applications is proposed. The proposed antenna is simply composed of three branch strips. By carefully selecting the positions and lengths of these branch strips, the desired resonant modes excited at 2.46/3.6/5.4 GHz with less than −10 dB frequency responses to the impedance can be achieved. In addition, an acceptable agreement is obtained between the simulation and the experiment. Also, the compact design of the proposed antenna, which has enough impedance bandwidth, makes the antenna suitable for WLAN and WiMAX operations. This article further presents and discusses the 2D radiation patterns and 2D gains according to the experiment results. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:161–166, 2015

Coupled‐fed shorted strip antenna with an inductively coupled branch strip for low‐profile, small‐size LTE/WWAN tablet computer antenna

AbstractA low‐profile, small‐size (10 × 40 mm2 on a thin dielectric substrate) planar LTE/WWAN antenna suitable for slim tablet computer application is presented. The antenna is formed by a coupled‐fed shorted strip antenna and an inductively coupled branch strip, with a chip inductor of 22 nH connected therebetween. At higher frequencies, owing to the high inductive reactance provided by the chip inductor, the branch strip will have very small effects on the antenna performances, and the coupled‐fed shorted strip antenna alone can provide a high‐band operation of 1710–2690 MHz. At lower frequencies, the embedded chip inductor can decrease the antenna's required resonant length, and the coupling feed can greatly widen the bandwidth of the excited resonant mode such that the antenna can cover a low‐band operation of 704–960 MHz. Good radiation characteristics of the antenna in the low‐band and high‐band operations are also obtained. Details of the proposed antenna and its experimental and simulated results are presented. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1041–1046, 2014

Small-Size LTE/WWAN Printed Loop Antenna With an Inductively Coupled Branch Strip for Bandwidth Enhancement in the Tablet Computer

The technique of using an inductively coupled branch strip for bandwidth enhancement of a simple printed loop antenna to achieve small size yet multiband operation to cover the LTE/WWAN bands (704-960 and 1710-2690 MHz) in the tablet computer is presented. The antenna's metal pattern occupies a small area of 10 × 34.5 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and is printed on a thin FR4 substrate. The branch strip is coupled to the loop antenna through a chip inductor. In the antenna's lower band, the branch strip can cause an additional resonance excited near a resonant mode contributed by the printed loop antenna and thereby greatly widens the antenna's low-band bandwidth to cover the 704-960 MHz band for the LTE700/GSM850/900 operations. While in the antenna's higher band, the chip inductor provides a high inductance and limits the excitation of the branch strip, thereby making the branch strip have negligible effects on the high-band operation. In this case, with the printed loop antenna excited in the higher band, the antenna can generate two higher order resonant modes to form a wide operating band for the GSM1800/1900/UMTS/LTE2300/2500 operations (1710-2690 MHz). Details of the proposed antenna are described, and the obtained results of the antenna are presented and discussed.

Small-Size Triple-Wideband LTE/WWAN Tablet Device Antenna

A small-size tablet device antenna with three wide operating bands to cover the Long Term Evolution/Wireless Wide Area Network (LTE/WWAN) operation in the 698 ~ 960-, 1710 ~ 2690-, and 3400 ~ 3800-MHz bands is presented. The antenna has a planar structure and is easy to fabricate on one surface of a thin FR4 substrate of size 10×45×0.8 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The antenna is formed by adding a first branch (branch 1, an inductively coupled strip) and a second branch (branch 2, a simple branch strip) to a coupled-fed shorted strip antenna (main portion), and the two branches are configured with the main portion to achieve a compact antenna structure. The three widebands are easy to adjust and can cover the LTE/WWAN operation, which includes the most commonly commercial LTE bands and WWAN bands (698 ~ 960 and 1710 ~ 2690 MHz) and the LTE 3.5-GHz band (3400 ~ 3800 MHz).

A NEW COUPLED-LOOP ANTENNA FOR EIGHT-BAND LTE/WWAN OPERATION IN ULTRA-THIN LAPTOP COMPUTER

A new structure of coupled-fed loop antenna con- nected with two branch radiators for eight-band LTE/WWAN (LTE700/GSM850/900/1800/1900/UMTS/LTE2300/2500) operation in the ultra-thin laptop computer is presented. The two branch strips of the antenna are e-cient radiators and contributing multi-resonant modes to greatly enhance the bandwidth of the antenna. The pro- posed antenna on the top shielding metal wall of the laptop display, with a planar and compact size of 12:5 £ 70 £ 0:8mm 3 , is suitable to be embedded inside the casing of the laptop computer. The proposed antenna is fabricated and tested, and good radiation performances are obtained. Compared with the existing published antennas, the volume of the planar antenna is quite small.

Design of a Ring Monopole Dual-Frequency Antenna Fed by Coplanar Waveguide

A printed ring-shaped monopole antenna fed by coplanar waveguide for use in the dual-band wireless communication system has been presented and investigated. By adding some branch strips inside the ring and changing its size, as well as the further optimization, the proposed antenna could work effectively within the scope of 2.4-2.484GHz and 5.15-5.825GHz frequency band. Practical antenna structure is fabricated. The details of the antenna design and both the theoretical and experimental results are discussed.

A modified virtual source method for off-axis unstable resonators with large equivalent Fresnel number

Physical significance of the ‘edge wave’ in the asymptotic solution of the diffraction by a single slit is expounded in detail. Basing on this concept, we modify the virtual source method to the calculation of the lowest eigenmode mode profile in both the positive and negative branch strip off-axis unstable resonators. The advantages of the method are that it is conceptually simple and requires only minimal computer time specifically for the resonators with large equivalent Fresnel number.

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 Coupled-Fed PIFA Employing T-Shaped Monopole with Two Stubs for Eight-Band LTE/WWAN Internal Mobile Phone

A compact antenna for eight-band LTE/WWAN operation internal mobile phone has been proposed in the paper. The proposed antenna is a three-dimensional structure, having a small size 15 × 40 × 3.8 mm3 on the top of the system circuit board. The designed antenna is formed by a T-shaped monopole with two stubs, a coupling strip, shorting strip and branch strip. It can generate two wide operating bands, including not only GSM1800/1900/UMTS2100/ LTE2300/2500 (1710–2690 MHz) but also LTE700/GSM850/900 (698–960 MHz). Based on the system ground plane of the antenna, the desired lower band can be achieved by the coupling strip and shorting strip, meanwhile, optimizing the two stubs of the T-shaped monopole can adjust the lower bandwidth accordingly. While the upper band can be obtained by the branch strip and T-shaped monopole with two stubs. Detailed operating principle and main parameters of the proposed antenna are also studied and discussed in this article. Finally, the simulated and measured results, such as return loss, antenna gain and radiation efficiency, are presented for the proposed antenna to demonstrate the reliability of the scheme.

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

Multiband printed and double-sided dipole antenna for WLAN/WiMAX applications

A novel type of printed and doubled-sided dipole antenna with multiband operation for wireless local area networks and worldwide interoperability for microwave access is presented. The antenna is composed of several symmetrical branch strips dipoles which are employed as resonators for multiband operation and a modified rectangular ground plane as a reflector. Prototype of the proposed antenna has been constructed and experimentally studied. The measured results of the tri-band not only explore wide −10 dB impedance bandwidths of 20, 14, and 15% at the operating bands of 2.5, 3.5, and 5.5 GHz respectively, but also show good agreement with the numerical predictions. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1019–1022, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26705

Compact Triple-Band Printed Antenna with a via Hole Connecting to a Parasitic Patch for Wlan and Wimax Applications

A compact triple-band printed antenna for wireless local area network and worldwide interoperability for microwave access (WLAN and WiMAX) applications is proposed. The antenna occupies only a small area of 34 × 11 mm2 and consists of branch strips, a parasitic patch and a modified ground plane. With the use of a plated-through via connecting the parasitic patch with the branch strips on the both sides, multiple impedance bandwidths covering WLAN/2.4/5.2/5.8 and WiMAX/3.5 are obtained. In addition, the proposed antenna has good radiation characteristic and peek gains to be 3.92, 2.8 and 3.8 dBi at 2.45, 3.5 and 5.5 GHz, respectively.

Design and Fabrication of Monopole Antenna with Three Branch Strips and Rectangular Slit Ground for WLAN/WiMAX Applications

본 논문은 WLAN/WiMAX 시스템에 적용 가능한 평면형 모노폴 안테나를 개발하였다. 제안된 안테나는 3개의 선로, 비대칭 접지면 그리고 접지면에 사각 슬릿을 가지며 WLAN 대역과 WiMAX 대역을 모두 포함하도록 설계하였다. 광대역 특성을 갖도록 선로 급전을 사용하였으며 RF-4 기판위에 제작되었다. 얻어진 시뮬레이션 결과는 실험결과와 잘 일치되었으며 VSWR 1:2을 기준으로 낮은 대역에서는 9.95%, 높은 대역에서는 76.05%의 임피던스 대역폭을 얻었다. 이러한 결과는 WLAN/WiMAX 시스템에서 요구하는 특성을 잘 만족시킨다. 또한 2D 그리고 3D 방사패턴과 이득에 측정결과가 제시되고 논의되었다.

Design of microstrip-fed monopole antenna with two branch strips and a rectangular slit ground for dual-band WLAN operations

A dual-band planar antenna that was developed for wireless local area network (WLAN) application is presented in this article.The proposed antenna, which has two strip lines for resonance and a rectangular ring strip for matching, was designed to cover the popular frequency spectra of the 2.4 and 5 GHz WLAN bands. Also, an asymmetric ground and a rectangular slit in the ground are introduced to enhance the performance of the proposed antenna. The proposed antenna, which is capable of dual-frequency operation, is fed by a strip line. 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 16.8% for the lower band and 58.14% for the upper band when VSWR < 2. This article also presents and discusses the 2D radiation patterns and gains according to the results of the experiment. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26225

Coupled-fed loop antenna with branch radiators for internal LTE/WWAN laptop computer antenna

A new antenna structure of internal long-term evolution/wireless wide area network (698–960/1710–2690 MHz) laptop computer antenna formed by a coupled-fed loop antenna connected with two branch radiators is presented. The two branch radiators consist of one longer strip and one shorter strip, both being efficient radiators and contributing multiresonant modes to greatly enhance the bandwidth of the antenna. The antenna's lower band is formed by a dual-resonant mode mainly contributed by the longer branch strip, while the upper band is formed by three resonant modes contributed respectively by one higher-order resonant mode of the longer branch strip, one resonant mode of the coupled-fed loop antenna alone, and one resonant mode of the shorter branch strip. The antenna's lower and upper bands can therefore cover the desired 698–960 and 1710–2690 MHz bands, respectively. The proposed antenna is suitable to be mounted at the top shielding metal wall of the display ground of the laptop computer and occupies a small volume of 4 × 10 × 75 mm3 above the top shielding metal wall, which makes it promising to be embedded inside the casing of the laptop computer as an internal antenna. Details of the proposed antenna are studied in the paper. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2662–2667, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25556

Compact monopole antenna with branch strips for WLAN/WiMAX operation

AbstractThis study proposes a novel and compact design for a printed monopole antenna using branch strips for wireless applications.The antenna consists of three strips and occupies only a small area of 14 × 9.5 mm2. By proper selection of dimensions as well as arrangement of the strips, desired resonant modes excited at 2.46/3.6/5.3 GHz with frequency responses of input impedance of less than −10 dB can be achieved. In addition, good agreement is obtained between the simulation and the experiment. Also, the compact design of the antenna, which has enough impedance bandwidth, near‐omnidirectional patterns and moderate gains, makes the antenna suitable for wireless local area network and worldwide interoperability for microwave access operations. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1858–1861, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25293