wireless charging

5/23/2018 wireless charging

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Session 2A6Microstrip and Printed Antennas, Phase Array

Antennas 1

Planar Antenna with a Grounded Inverted L-shaped Strip for WUSB Application

Wen-Shan Chen, Bau-Yi Lee, Ching-Hung Chen, .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 198

A Novel Printed Antenna for PDA Phone

Wen-Shan Chen, Bau-Yi Lee, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199

The Ambiguity Problem of a LCMV-based Space-time Cascade 2D Array

Ho-Hsuan Chang, Tsung-Cheng Wu, Shih-Chiang Lin, ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 200

A Franklin Array Antenna for Wireless Charging Applications

Shih-Hsiung Chang, Wen-Jiao Liao, Kuo-Wei Peng, Chih-Yao Hsieh, .. .. .. .. . .. .. . .. .. .. . .. .. .. .. 201

A Miniatured WLAN/Wi-MAX Chip Antenna for Mobile Phone Applications

Long-Kun Li, Wen-Jiao Liao, Shao-En Hsu, ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 202A Beam Switching Planar Yagi-patch Array for Automotive Applications

Shao-En Hsu, Wen-Jiao Liao, Wei-Han Lee, Shih-Hsiung Chang, .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 203

Dual-band Dual-polarized Hybrid Antenna Array

Li-Na Zhang, Shun-Shi Zhong, Xianling Liang, .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 204

An Outdoor Bistatic Scattering Assessment Using Array Antennas

Chih-Yao Hsieh, Wen-Jiao Liao, Long-Kun Li, .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 205

Microstrip Antenna Subarray for Circularly-polarized Synthetic Aperture Radar

Merna Baharuddin, Josaphat Tetuko Sri Sumantyo, Hiroaki Kuze, .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. 206

Design of a Printed Antenna Array for Cost-effective ATE to Reduce the Radiated EMI Yield Loss

Cheng-Nan Hu, Hsuang-Chung K o, Deng-Yao Chang, .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 207

Wang-shaped Patch Antenna with a Simple Feed Network

Chi H. Wong, Kwok L. Chung, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

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198 Progress In Electromagnetics Research Symposium Abstracts, Xian, China, March 2226, 2010

Planar Antenna with a Grounded Inverted L-shaped Strip forWUSB Application

Wen-Shan Chen, Bau-Yi Lee, and Ching-Hung ChenSouthern Taiwan University, Taiwan

Abstract To increase the transmitted speed of Pen Driver, Wireless-USB (WUSB) uses thefirst group spectrum (3.14.85 GHz) of 802.15.3a standard to process huge amount of data. Thispaper presents a printed antenna fabricated on a printed circuit board (PCB) with a small size of10 29 0.8 mm3. The proposed antenna consists of a rectangular radiation patch (L1W1) andground plane that has a rectangle (L3W) plate and an inverted L-shaped strip. Without addingthe inverted L-shaped strip, the proposed antenna has only one resonated mode at 5 GHz thatoperates frequency band from 4.2 to 5.41 GHz. This frequency band can not cover the wireless-USB (WUSB) operation band. After the inverted L-shape strip was added, three resonatedmodes located at 3.23, 4.06 and 5.22GHz were produced. The low operated band is resonatedby the inverted L-shape strip; the intermediate operated band is resonated by the rectangularradiation patch and the inverted L-shape strip; the high operated band is resonated by therectangular radiation patch. The combination of these operated bands provides an impedancebandwidth of 3.07 to 5.86 GHz, which covers the WUSB operation band. The effects of theantenna with different ground length are also investigated. The antenna covers wide bandwidthand keeps the impedance bandwidth for different ground length. In addition, the proposedantenna has advantages of simple structure, wide bandwidth, low cost, low profile, and goodradiation characteristics. Simulated and measured results of the proposed antenna design aredescribed, and experimental results of a constructed prototype are presented and discussed.


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Progress In Electromagnetics Research Symposium Abstracts, Xian, China, March 2226, 2010 199

A Novel Printed Antenna for PDA Phone

Wen-Shan Chen and Bau-Yi Lee

Southern Taiwan University, Taiwan, R.O.C.

Abstract Multi-band antenna has become the mainstream for modern wireless communica-tion system because the wireless products carry two or more functions. PIFA and multi-layersantennas have been used in multi-band applications for more than a decade; however, these an-tennas need extra height to place in the circuit board. Planar monopole antenna having theadvantages of low profile, low cost and ease to fabricate becomes a promising candidate in multi-frequency operation. Owning to the portable and compact of wireless products, the physicalsize of antenna has to fit into the system architecture. Folded or meandered monopole, whichcan easily reduce the antenna size, plays an important role in compact antennas. Insufficientbandwidth is always come with these folded types of antennas, especially at lower frequencybands. Using parasitic element, which can couple or excite extra path, is a useful method to in-crease the required bandwidth. This paper presents a dual mode method to fulfill the bandwidthrequirement.

The proposed novel planar antenna has a simple inverted-U shaped in driven part and two low

frequency paths with a tunable slot in ground plane. The inverted-U element and ground planeare printed on the same side of the substrate. The total length of inverted-U operates a quarterwavelength of 1200 MHz and the mode is not used in this design. The other two resonant modesat 1800 and 2400 MHz are also produced by using the inverted-U element. The 1800 MHz and2400 MHz modes operate frequency bands of DCS (17101880 MHz), PCS (18501990 MHz),UMTS (19202170MHz) and WLAN (24002484 MHz). The two low frequency paths operatetwo low frequency modes. By adjusting a slot located between the two low frequency paths, thetwo low frequency modes are close at 900 MHz to operate GSM (890960 MHz) band. The overalldimension of proposed antenna is 100 mm (length) 60 mm (width) 0.8 mm (thickness), and itwould be used in multi-network PDA phone.

Figure 1.


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The Ambiguity Problem of a LCMV-based Space-time Cascade 2D

Array

Ho-Hsuan Chan, Tsung-Cheng Wu, and Shih-Chiang LinDepartment of Communication Engineering, I-Shou University, Taiwan

Abstract For a wideband beamforming system, the propagating signals are processed andcombined temporally as well as spatially, which thus is a space-time two dimension (2D) array,to extract the desired information such as the directions of propagation and their frequencycontents. We discussed and compared the performance of three different space-time 2D arrayswhich are the space-time joint (STJ), the time-space cascade (TSC) and the space-time cascade(STC) processing configuration, respectively. The linear constraint minimum variance (LCMV)algorithm is applied to calculate the dynamic weighting functions for these 2D adaptive arrays.The STJ processor can achieve better resolution, signal separation and interference suppressioncapacities than the other two types do, but the joint of space and time processing is subjectto heavy computing load on the evaluation and updating the array weighting functions. On theother hand, both the STC and TSC processors have the implementation advantage than STJ dueto simplicity and lower computing load. However these two processors will encounter detection

ambiguity problem which the bearing measurements made give ambiguous DOA and frequencycontents under the multibeam constraint conditions. We explained and derived theoretically theexistence of ambiguity problem and provided simulation results to demonstrate our arguments.

There is no much novelty the topics of space-time 2D array and beamforming techniques, butit seems that there were no much references can be traced regarding the ambiguity problempresented in this article. We still wonder whether or not the ambiguity problem is not worthyto mention or there may be other view points on this problem. We sincerely hope that we canattract more attention or may stimulate possible discussions on this subject.


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A Franklin Array Antenna for Wireless Charging Applications

Shih-Hsiung Chang, Wen-Jiao Liao, Kuo-Wei Peng, and Chih-Yao HsiehDepartment of Electrical Engineering, National Taiwan University of Science and Technology

43, Sec. 4, Keelung Rd., Taipei 106, Taiwan

AbstractA Frankin array antenna is proposed in this work to be used the receiving antennafor wireless charging applications. It is a fascinating idea to use radio wave as the power source.However, due to the relative long wavelength, the power density of microwave radiation dilutesas it propagates. According to power budget analysis, at a distance of one meter, if transmittingand receiving antennas of moderate gains are used, only a few mW is available with one wattpower transmission. In order to enhance the available power level and increase the separationdistance, larger antennas, which intercept more radiated power, can be employed.

The proposed planar Franklin array antenna contains 8 antennas as shown in Fig. 1(a). EachFranklin array antenna comprises 4 patches connected in series. Antennas are grouped into twosets and placed perpendicularly on top a metal ground plane. The overall antenna panel size is52 cm by 52 cm, and the thickness is 6.5 mm. Fig. 1(b) provides the translated farfield radiationpattern measured in a spherical nearfield chamber. The maximum gain is approximately 12 dBi.

Note there are a couple of side-lobes, which are due to the extended patch element spacing.Wireless charging performance was evaluated by connecting the Franklin array antenna with loadsand the RF rectification circuitry, which is made of RF diodes. Experiment results indicate thatby employing a large antenna aperture, the charging distance can be elongated to a few meters.A one mF super capacitor can be charged up within tens of seconds. Different rectification circuitconnecting fashions were also attempted. By combing the received RF power first with a powerdivider, then performing rectification with a single RF rectification circuit, the charging distancecan be optimally extended. On the other hand, if the RF power from each Franklin array isrectified first, then combined as DC sources, the charging distance is limited since certain powerlevel ( 0 dBm) is required to turn on RF diodes. However, at a short distance, the latterconnecting fashion provides more power to the load.

Figure 1: (a) Fabricated Franklin array antenna. (b) Measured radiation pattern.


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A Miniatured WLAN/Wi-MAX Chip Antenna for Mobile Phone

Applications

Long-Kun Li, Wen-Jiao Liao, and Shao-En HsuDepartment of Electrical Engineering, National Taiwan University of Technology, Taiwan, R.O.C.

Abstract The wireless communication market has been growing rapidly since the last twodecades. Now, people not make phone calls, but also demand to transmit and receive datafrom mobile devices. Therefore, connection capability to wireless local area network (WLAN) orworldwide interoperability micro-wave access (Wi-MAX) is a must. In recent years, due to thepopularity of mobile devices and the demand of multiple system integration, antenna miniatur-ization becomes an important research topic. Conventional antenna miniaturization techniquesinclude using meandered metal strip structure and employing dielectric loading. Meander linestructures maintain the electric length required for resonance while minimize the antenna physicalsize. The dielectric loading method uses high dielectric constant materials to slow down the wavevelocity, which in turns reduces the resonance length. The so-called chip antenna combinesabove two techniques to further minimize the antenna size.

In this work, compact WLAN/Wi-MAX dual band chip antennas for mobile phones are presented.Due to different band allocations in different regions, two chip antenna designs are proposed. Oneworks for WLAN(2.4 2.48, 5.15 5.35, 5.725 5.85 GHz) and Wi-MAX(3.4 3.7 GHz) bands.The antenna dimensions, as shown in Fig. 1, are 3 mm 9 mm 1.6 mm. The other covers theWLAN and Wi-MAX band at 2.5 2.7GHz. Its dimensions are 3 mm 11mm 1.6mm. Bothchip antenna designs comprise two resonant branches and take advantage of branches secondorder resonance to create two near resonant frequencies. Such technique helps to achieve a triple-band response. One attractive feature of the proposed chip antenna is that no empty space isneeded, which is suitable for mobile devices. An FR4 substrate of 45 mm by 100 mm serves asthe platform to mount the chip antenna.

Simulations and measurements on return loss spectra as well as radiation patterns were performedand are largely agree. The radiation patterns are omni-directional in general as shown in Fig. 2.Simulated results indicate the resonance is largely invariant to the changes in test board size, sothe proposed miniatured chip antenna is particularly attractive for mobile devices such as the

PDA, smart phone or notebook.

Figure 1: Proposed WLAN/Wi-MAX(3.4 3.7 GHz) chip antenna.

Figure 2: 3-D radiation pattern (2.4 GHz) of the pro-posed chip antenna.


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A Beam Switching Planar Yagi-patch Array for Automotive

Applications

Shao-En Hsu, Wen-Jiao Liao, Wei-Han Lee, and Shih-Hsiung ChangDepartment of Electrical Engineering, National Taiwan University of Science and Technology, Taiwan

AbstractInterference and multi-path fading in urban and indoor environment are importantissues for wireless communications. In this work, a Yagi patch antenna of four directive beamsis proposed to counteract multi-path interference. The beam switching antenna, as shown inFigure 1, comes with the Yagi patch antenna, a one-to-four RF switch and the control circuit.The Yagi patch antenna comprises four driven patch elements, which are connected via a one-to-four RF switch and five parasitically-coupled director patch elements. By selecting a specificthrough path of the RF switch, RF power is fed to one of the driven patch elements. Sincedirective radiating elements are used, the beam switching antenna can utilize spatial diversity toextend connection distance and prevent interference.

Figure 2 shows the configuration of the beam switching planar Yagi-patch array. The antenna isdesigned to operate around GSM 1800/1900 MHz for cellular phone uses. The size and the height

of the fabricated prototype antenna are 293 mm

293 mm

3 mm, respectively. Measurementresults indicate the antennas gain is approximately 9.478 dBi with a 3 dB beamwidth of 68degrees. Detailed design parameters as well as performance features such as operational frequency,gain, isolation, 3 dB beamwidth, front-to-back ratio and squint angle are reported in this paper.

Because of the planar structure, this antenna can be employed for automotive environment. Forinstance, the planar antenna configuration can be mounted on top of a vehicle for with a lowprofile. The switching directive beam enables the moving vehicle to track a specific base stationand extends the communication distance. Such a planar beam switching antenna can be used formobile devices to ensure connection quality via spatial diversity.

Antenna 3

Antenna 1

RF

Switch

Antenna 2

Antenna 4

Figure 1: One-to-four beam switching antenna sys-tem.

Figure 2: A beam switching planar Yagi-patch array.


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Dual-band Dual-polarized Hybrid Antenna Array

L. N. Zhang1, S. S. Zhong1, and X. L. Liang2

1School of Communication and Information Engineering, Shanghai University, China2Department of Electronic Engineering, Shanghai Jiao Tong University, China

Abstract Recently, the dual-band and dual polarized antenna array have been studied forsatellite and wireless communication applications, particularly for the synthetic aperture radar(SAR) application [1, 2]. The microstrip antenna (MA) and the dielectric resonator antenna(DRA) as two classes of array elements have been investigated and extensively used in the lastdecades. The microstrip antenna has good performance in lower frequency, but in higher fre-quency, its radiation efficiency deteriorates apparently, for example, it decreases by 15% as thefrequency rises from C band to X band. Compared to the MA, the radiation efficiency of the DRAis as high as 95% even for frequencies up to 10 GHz, due to the absence of inherent conductorlosses [3].

In this paper, we propose a novel hybrid antenna array with the combination of MA and DRAelements for the dual-band dual-polarized SAR application. Owing to higher efficiency of the

DRA, the DRA is used as the higher frequency radiation element in X band. In order to obtainthe dual polarization and to reduce the cross-polarization level, horizontal polarization of theDRA elements is fed in the center of the DR and the vertical polarization fed by means of the180 out of phase feed technique. For lower frequency of S band, the traditional microstrip dipoleantenna is adopted as the element, where two separate orthogonal microstrip dipoles are usedto provide the horizontal and vertical polarization, respectively. The spacing of the elements isabout 0.70 at 9.6 GHz and about 0.70 at 3.2GHz. As a test model, the 2 1 elements and2 6 elements are simulated and analyzed.

Array simulation results shows that the impedance bandwidths of return loss less than 10dBare 6.6% (3.083.29GHz) for S band and 11.5% (8.9210.01 GHz) for X band, respectively. Thecross-polarization levels of the antenna array are 40 dB for X band and 27dB for S band inboth planes respectively. The antenna array has advantages such as small size, simples structures,low cost, high efficiency, perfect polarization purity and easy to expand into a large array. Thusit is promising candidate for the SAR application.

REFERENCES

1. Pozar, D. M. and S. D. Targonski, A shared-aperture dual-band dual-polarized microstriparray, IEEE Trans. Antennas and Propagation, Vol. 49, No. 2, 150157, 2001.

2. Zhong, S. S., Z. Sun, and X. R. Tang, Progress in dual-band dual-polarization shared-apertures SAR antennas, Frontiers of Electrical and Electronic Engineering in China, Vol. 4,No. 3, 323329, 2009.

3. Lai, Q., G. Almpanis, C. Funmeaux, H. Benedickter, and R. Vahldieck, Comparison of theradiation efficiency for the dielectric resonator antenna and the microstrip antenna at Kaband, IEEE Trans. Antennas and Propagation, Vol. 56, No. 11, 35893592, 2008.


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An Outdoor Bistatic Scattering Assessment Using Array Antennas

Chih-Yao Hsieh, Wen-Jiao Liao, and Long-Kun LiDepartment of Electrical Engineering, National Taiwan University of Science and Technology

43, Sec. 4, Keelung Rd., Taipei 106, Taiwan

Abstract Passive coherent detection (PCL), which is also known as passive radar, is of in-creasing interest lately. In a passive radar system, the transmitting and receiving antennas arenot located at the same position. Therefore, it detects targets bistatic scattering instead ofmonostatic scattering in conventional radars. In this work, we designed an experiment whichevaluates the bistatic radar cross section from targets in the UHF band. The preliminary mea-surement configuration is shown in Fig. 1, which includes two directive antennas connected toa network analyzer. One is a four dipole array of approximately 10 dBi gain, while the otheris a Yagi antenna of 7 dBi gain. Both antennas are aimed toward the target. Since the outputpower from the NA is relatively weak and the bistatic RCS from the target may be small incertain angles, the transmitted power is cranked up to 50 dBm using RF components includingpower amplifiers, attenuators, circulators and terminations. In order to evaluate targets bistaticscattering correctly, interference from nearby clutters need to be minimized. Hence, the testing

range is set up on a buildings roof top to avoid reflections from other buildings.The bistatic RCS of a scattering target is not only determined by the target geometry, but alsoa complicated function of incident angle, reflection angle, frequency, and the targets surfaceproperty. As a result, several sets of experiments were proposed to assess the targets RCScharacteristics and the measurement validness as well. Parameters studied include targets shape,orientation, distance to antenna, and antenna polarization. For example, Fig. 2 is the scatteringspectra of co-pol and cross-pol antenna setups. The target is a cardboard box wrapped inaluminum foil and is located 8 meters away from the transmitting and receiving antennas. Thedifference is around 20 dB indicating the planar surfaces of the target provides little cross-polreflection. Note because the size of the target is close to the wavelength, the scattering spectraexhibit some interference patterns. The bistatic RCS are calculated according to the radarequation. Although the RCS value varies under different testing scenarios, the targets electricalsizes, in general, are three to ten times larger than their physical sizes. Also, the RCS of a boxtarget is much larger than the one of a spherical target.

According to the measurement results, the variation in bistatic RCS complies with physicalexpectation. As to the future work, the target should be elevated to reduce interference frombackground clutters.

Figure 1: Testing range setup. Figure 2: Scattering spectra of co-pol and cross-polantennas.


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Microstrip Antenna Subarray for Circularly-polarized Synthetic

Aperture Radar

Merna Baharuddin, Josaphat Tetuko Sri Sumantyo, and Hiroaki KuzeCenter for Environmental Remote Sensing, Chiba University

1-33, Yayoi, Inage, Chiba 263-8522, Japan

AbstractThe design of a circularly-polarized microstrip antenna subarray intended for use incircularly-polarized synthetic aperture radar (CP-SAR) systems operated in L-Band (1.27 GHz)is presented. The CP-SAR sensor is a new sensor for Earth observation applications, with theadvantage of sensitive measurements on Earth object characteristics, providing greater amountof information than conventional linear-polarization systems. Microstrip antenna has the advan-tages of lightweight, low profile, and low volume, as well as the relatively low fabrication cost. Inspite of its narrow bandwidth and low gain, microstrip antenna is a suitable choice for airborneSARs. The subarray is the essential component that will compose the full array CP-SAR antenna.The full antenna, in turn, will be implemented on an Unmanned Aerial Vehicle (UAV) CP-SAR,currently under development in the Microwave Remote Sensing Laboratory, Chiba University.The array antenna requirements are (i) broad-band input impedance, (ii) sufficient Axial Ratio

bandwidth, (iii) a cosecant-squared beam pattern in the elevation plane (E-plane), (iv) a pencilbeam in the azimuth plane (H-plane), (v) relatively good gain and (vi) low cross polarizationlevels. There are a number of technical challenges in achieving such specifications required forthe CP-SAR sensor. The subarray is comprised of CP microstrip elements, and every element isa dual-polarized, Right Handed Circular Polarization (RHCP) and Left Handed Circular Polar-ization (LHCP), microstrip antenna. The microstrip element is an elliptical patch antenna whichis radiating circularly-polarized wave. A single proximity-coupling method is applied for feedingthe antenna element. The subarray design will involve the right spacing between elements inorder to minimize the mutual coupling and to achieve the required pattern. A well-matched feed-ing system is also indispensable for the implementation of the dual-polarized circularly-polarizedsubarray system.


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Design of a Printed Antenna Array for Cost-effective ATE to

Reduce the Radiated EMI Yield Loss

Cheng-Nan Hu1, Hsuang-Chung Ko2, and Deng-Yao Chang2

1CRC, Oriental Institute of Technology

No. 58, Sec. 2, Sihchuan Rd, Ban-Ciao City, Taipei County, Taiwan, R.O.C.2King Yuan Electronics Co. Ltd.

No. 58, Sec. 2, Sihchuan Rd, Ban-Ciao City, Taipei County, Taiwan, R.O.C.

Abstract RF semiconductor devices are changing to match the needs of increasingly inno-vative wireless standards. In turn, device functionality and integration drive core parametric,configuration, and usage trends for RF ATE (Auto-Test-Equipment) and signal bandwidths andcarrier frequencies supporting greater data throughput rates are increasing steadily [13]. Usually,RFIC manufacturers conduct the Go No-Go test procedure (Fig. 1(a)) to perform the qualifi-cation test. However, this approach has to suffer the yields loss caused by radiated EMI noisesexisting in the testing environment.

To improve the radiated EMI yield loss, design of a multi-band, dual-polarized printed antennaarray is proposed to be implemented onto the load board of the ATE (Auto-Test-Equipment) asthe EMI sensor (Fig. 1(c)) to monitor the existing interference signals such that the correlationbetween the test data and background noise can be analyzed in order to identify the root causesof yield loss. When the radiated EMI is detected at production line, a re-testing procedure istrigged by ATE test program (Fig. 1(b)) to reduce the radiated EMI yield loss.

In this study, theoretical analysis of a specified PHS transceiver IC based on the Monte-Carloprocedure validates the proposed cost-effective ATE design approach. Experimental results of aprinted antenna array design confirm the performance of EMI sensor. System validation of thespecified device that occurred with a suspected EMI low yield in the production line indicatesthat the proposed approach can reduce yield loss from 34% to 13%, or by 21% which is veryconsistence with the numerical results of 21.3% using Monte-Carlo approach.


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Wang-shaped Patch Antenna with a Simple Feed Network

Chi H. Wong and Kwok L. Chung

Department of Electronic and Information Engineering, The Hong Kong Polytechnic UniversityHung Hom, Hong Kong, China

Abstract Microstrip patch antennas have attracted much attention of antenna researchersbecause of its low cost, low profile and easy fabrication, but narrow bandwidth is a major dis-advantage that limits the applications of microstrip antennas. Methods to enhance impedance(or return-loss) bandwidth including the addition of U-slot [1], the E-shaped patch [2, 3], andthe meandering-probe with stacked patch [4]. The U-slot patch and E-shaped patch designs arecapable of>30% return-loss (10-dB) bandwidth but suffer from high cross-polarization (x-pol)of greater than 15 dB in one plane [13]. The Meandering probe fed stacked patch enhancesthe impedance bandwidth up to 37% (SWR < 1.5) and the x-pol down to 20 dB. However, itrequires an additional patch and a complex probe fabrication [4]. Recently, a Wang-shaped patchfed by a dual L-probe with an enhanced return loss bandwidth of 42% has been reported [5].Two mirrored E-shaped patches are combined to form a single patch. This combination makesthe topological shape of the patch to resemble a Chinese character, (pronouncedWang), hence

this novel patch is denoted as Wang-shaped patch antenna. Wang-shaped patch has a symmetricgeometry in both the principal planes whereas the E-shaped patch has current flows in oppositedirections of E-field. The latter causes the asymmetric radiation patterns and the high x-pollevel in H-plane. Wang-shaped patch comes to solve such problems by balancing current flowsin opposite directions. An external phase shifter was used in the proof-of-conceptversion [5]. Byexciting two identical L-probes with anti-phase currents in equal magnitudes, the cancellation ofleakage radiation from the vertical probes and hence the suppression of cross-polarization havebeen achieved.

In this paper, a simple feed network is designed to replace the external phase shifter for a Wang-shaped patch. This antenna is aimed to be operated in a frequency range of 1.66 GHz to 2.43 GHzfor covering the major standards in mobile communications. A dual L-probe feed is proposedin the current design. The feed network is applied to excite the probes with equal magnitudecurrents in 180 deg out of phase, as the similar function of an external phase shifter. A 1.52-mmthick Rogers RO3003 dielectric substrate (r = 3.0, tan = 0.0013) is used to facilitate the

feed network. The dual L-probe fed Wang-shaped patch antenna features a 10-dB return-lossbandwidth of 37.7%, whilst the cross-polarization levels are suppressed below 20 dB within thebandwidth range of 1.78 GHz and 2.31 GHz. The broadside gain is simulated as high as 6.5 dBiat the mid-band frequency. The detailed antenna geometry and the measurement results will bepresented and discussed in the conference.

REFERENCES

1. Luk, K. M., Y. X. Guo, K. F. Lee, and Y. L. Chow, L-probe proximity fed U-slot patchantenna,Electronic Letters, Vol. 34, 18061807, Sep. 1998.

2. Yang, F., X. X. Zhang, X. Ye, and Y. Rahmat-Samii, Wide-band E-shaped patch antennasfor wireless communications,IEEE Trans. Antennas Propagat., Vol. 49, 10941100, Jul. 2001.

3. Wong, K. L. and W. H. Hsu, A board-band rectangular patch antenna with a pair of wideslits, IEEE Trans. Antennas Propagat., Vol. 49, 13451347, Sep. 2001.

4. Lai, H. W. and K. M. Luk, Wideband stacked patches antenna fed by a meandering probe,Electronic Letters, Vol. 41, Mar. 2005.

5. Fung, H. Y. and K. L. Chung, A Wang-shape suspended patch antenna, Proceedings of the11th Australian Symposium on Antennas, 18, Sydney, Australia, Feb. 1819, 2009.

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