A Miniature GPS Planar Chip Antenna Integrated with Low Noise Amplifier 1 Chao-Wei Wang*, Yen-Ming Chen, Chang-Fa Yang Department of Electrical Engineering, National Taiwan University of Science and Technology 43, Keelung Road, Sec. 4, Taipei, Taiwan, ROC e-mail: M9407303@mail.ntust.edu.tw*, M9307318@mail.ntust.edu.tw, cyang@mail.ntust.edu.tw Shun-Tian Lin Department of Mechanical Engineering, National Taiwan University of Science and Technology e-mail: stlin@mail.ntust.edu.tw Chang-Lun Liao, Chuan-Ling Hu, Chant Sincere CO., Ltd. (COXOC) http://www.coxoc.com.tw/ e-mail: M9203515@mail.ntust.edu.tw, aaron.hu@coxoc.com.tw Introduction A planar chip antenna integrated with a low noise amplifier (LNA) for GPS applications at 1.575GHz is presented in this summary. Software packages, XFDTD [1] and HFSS [2] have been applied to design the chip antenna having dimensions of 10mm(L) 8mm(W) 0.8mm (H), as shown in Fig. 1. An insert molding approach is applied to manufacture the antenna, where meandered metal strips are enclosed with liquid crystal polyester (LCP) to form the chip antenna [3]-[5]. Thus, this chip antenna comprises a radiating structure of multiple meandered conducting strips packed with an LCP dielectric composite material to achieve size, performance characteristics and cost effectiveness superior to conventional GPS ceramic patch antennas. The 10 8 0.8mm 3 compact surface-mount chip antenna is fully compatible with hand- and reflowattachment processes. Also, no additional impedance-matching circuit is required so that the occupied length of the antenna built in a GPS receiver operating at 1.575GHz is just 10mm. For the GPS LNA, an RF transistor (NEC µpc8211tk) is employed, together with input/output matching circuits using a band-pass topology to achieve low noise figure and impedance matching [6]. This LNA is a high gain cascade amplifier, and a negative feed-back topology is used to increase the stability. A software package, ADS [7] has been applied to design the LNA having dimensions of 25mm(L) 25mm(W) 3mm(H). The GPS chip antenna can be integrated with the LNA to form a remote active GPS antenna with dimensions of 25mm(L) 25mm(W) 5mm(H), or built in the GPS receiver together with the LNA. A 100mmx80mm test board has been employed to 1 This work was supported in parts by Chant Sincere Company, Ltd. (COXOC) and the National Science Council of ROC under Grant NSC 94-2213-E-011-025. 1-4244-0878-4/07/$20.00 2007 IEEE 1241
simulate the effects of the GPS receiver for evaluating the performance of the build-in active GPS chip antenna. Results Figure 2 shows the return loss of the GPS planar chip antenna mounted on the 100mm 80mm test board, obtained from both simulations and measurements. The simulations were performed by applying the XFDTD and HFSS software packages. A vector network analyzer (Agilent E8362B PNA) was used to measure the return loss of the chip antenna on the test board. The bandwidth of the chip antenna for -10dB return loss is about 100MHz with a central frequency of 1.575GHz. Figure 3 demonstrates the simulated and measured radiation patterns at 1.575GHz for the GPS planar chip antenna mounted on the 100mm 80mm test board. The XFDTD and HFSS software packages are again employed to obtain the simulations. As for the measurements, a far-field anechoic chamber (NSI 800F-10/WavePro FFC-700S) for 0.8-18GHz antenna tests together with the PNA has been used to perform the antenna pattern measurements in three major cuts, as shown in Fig. 3. Good agreements between simulations and measurements have been obtained. A list of the antenna properties for this design is given in Table I, which shows good performance in bandwidths and antenna patterns for GPS applications, requiring omni-directional receptions. Also, a right-hand circular polarization (RHCP) with an axial ratio of 2.4 in broadside is obtained due to the coupling of the antenna with the ground plane of the test board. Figure 4 shows the measured result of the S-parameters and noise figure for the LNA. The vector network analyzer (Agilent E8362B PNA) and spectrum analyzer (Agilent E4445A PSA) were used to measure the S- parameters and noise figure, respectively. The gain and noise figure of the LNA are about 23.7dB and 1.99dB at 1.575GHz. A list of the LNA properties for this design is given in Table II. Figure 5 compares the GPS planar chip antenna mounted on the test board with a conventional GPS ceramic patch antenna by using the same LNA and GPS receiver. It demonstrates that the number of the positioning satellites received and the ratios of the received signals versus noises (C/N) by applying the proposed active GPS chip antenna are good. (the largest C/N is 51 for this GPS receiver module.) The new active GPS chip antenna is particularly suitable for handheld positioning devices, which prefer a build-in and omni-directional antenna. References [1] XFDTD, User s manual, REMCOM Corp., USA. [2] HFSS, User s manual, Ansoft Corp., USA. 1242
[3] C.-L. Hu, M.-C. Pan, S.-T. Lin, C.-F. Yang, K.-C. Cheng, S.-F. Wang, L.-S. Jang, C.-L. Liao, A fabrication method of small chip antennas, Taiwan patent # I241052, Oct. 1, 2005 Dec. 28, 2024. [4] Warren L. Stutzman, Gary A. Thiele, Antenna Theory and Design, 2nd Edition, John Wiley & Sons, Inc., 1997. [5] T. J. Warnagiris and T. J. Minardo, Performance of meandered line as an electrically small antenna, IEEE Trans. Antennas and Propagation, vol. 46, pp. 1797-1801, December 1998. [6] George D. Vendelin, Anthony M. Pavio, and Ulrich L. Rohde, Microwave Circuit Design Using Liner and Nonlinear Techniques, 2 nd Edition, Wiley, 2005. [7] ADS, User s manual, Agilent Corp., USA. Table I Performance of the GPS chip antenna on a 100mm 80mm test board. Dimension (mm 3 ) 10 8 0.8 Central Frequency (GHz) 1.575 Bandwidth (MHz) 100 Polarizaion RHCP Axial Ratio 2.4 Gain (dbc) 0.9 Efficience(%) 72 VSWR 2.0 (max) Return Loss (db) -10 (max) Pattern Omni-Directional Impedance (Ω) 50 Operating Temperature ( ) -25 ~ +85 Manufacture LCP Insert Molding Technology Figure 1 Dimensions of the GPS chip antenna. Figure 2 The return loss of the GPS chip antenna mounted on a 100mm 80mm test board. θ=90º ψ=0º ψ=90º Figure 3 Simulations and measurements of the antenna patterns for the GPS chip antenna mounted on a 100mm 80mm test board at 1.575GHz. 1243
Table II Performance of the GPS Low Noise Amplifier. Frequency Range (GHz) 1.552~1.591 Power Consumption 30mW(3V,10mA) Input Return Loss(dB) -5.9 Output Return Loss(dB) -15.8 Isolation(dB) -35.6 Gain(dB) 23.7 Noise Figure(dB) 1.99 Stability >3 Impedance (Ω) 50 Figure 4 Measurements of the S-parameters and noise figure for the GPS LNA. (a) (b) Figure 5 The number of the positioning satellites received and the ratios of the received signals versus noises (C/N) by using: (a) Conventional GPS ceramic patch antenna, (b) GPS planar chip antenna. 1244
易迪拓培训 专注于微波 射频 天线设计人才的培养网址 :http://www.edatop.com 射频和天线设计培训课程推荐 易迪拓培训 (www.edatop.com) 由数名来自于研发第一线的资深工程师发起成立, 致力并专注于微波 射频 天线设计研发人才的培养 ; 我们于 2006 年整合合并微波 EDA 网 (www.mweda.com), 现已发展成为国内最大的微波射频和天线设计人才培养基地, 成功推出多套微波射频以及天线设计经典培训课程和 ADS HFSS 等专业软件使用培训课程, 广受客户好评 ; 并先后与人民邮电出版社 电子工业出版社合作出版了多本专业图书, 帮助数万名工程师提升了专业技术能力 客户遍布中兴通讯 研通高频 埃威航电 国人通信等多家国内知名公司, 以及台湾工业技术研究院 永业科技 全一电子等多家台湾地区企业 易迪拓培训课程列表 :http://www.edatop.com/peixun/rfe/129.html 射频工程师养成培训课程套装该套装精选了射频专业基础培训课程 射频仿真设计培训课程和射频电路测量培训课程三个类别共 30 门视频培训课程和 3 本图书教材 ; 旨在引领学员全面学习一个射频工程师需要熟悉 理解和掌握的专业知识和研发设计能力 通过套装的学习, 能够让学员完全达到和胜任一个合格的射频工程师的要求 课程网址 :http://www.edatop.com/peixun/rfe/110.html ADS 学习培训课程套装该套装是迄今国内最全面 最权威的 ADS 培训教程, 共包含 10 门 ADS 学习培训课程 课程是由具有多年 ADS 使用经验的微波射频与通信系统设计领域资深专家讲解, 并多结合设计实例, 由浅入深 详细而又全面地讲解了 ADS 在微波射频电路设计 通信系统设计和电磁仿真设计方面的内容 能让您在最短的时间内学会使用 ADS, 迅速提升个人技术能力, 把 ADS 真正应用到实际研发工作中去, 成为 ADS 设计专家... 课程网址 : http://www.edatop.com/peixun/ads/13.html HFSS 学习培训课程套装该套课程套装包含了本站全部 HFSS 培训课程, 是迄今国内最全面 最专业的 HFSS 培训教程套装, 可以帮助您从零开始, 全面深入学习 HFSS 的各项功能和在多个方面的工程应用 购买套装, 更可超值赠送 3 个月免费学习答疑, 随时解答您学习过程中遇到的棘手问题, 让您的 HFSS 学习更加轻松顺畅 课程网址 :http://www.edatop.com/peixun/hfss/11.html `
易迪拓培训 专注于微波 射频 天线设计人才的培养网址 :http://www.edatop.com CST 学习培训课程套装该培训套装由易迪拓培训联合微波 EDA 网共同推出, 是最全面 系统 专业的 CST 微波工作室培训课程套装, 所有课程都由经验丰富的专家授课, 视频教学, 可以帮助您从零开始, 全面系统地学习 CST 微波工作的各项功能及其在微波射频 天线设计等领域的设计应用 且购买该套装, 还可超值赠送 3 个月免费学习答疑 课程网址 :http://www.edatop.com/peixun/cst/24.html HFSS 天线设计培训课程套装套装包含 6 门视频课程和 1 本图书, 课程从基础讲起, 内容由浅入深, 理论介绍和实际操作讲解相结合, 全面系统的讲解了 HFSS 天线设计的全过程 是国内最全面 最专业的 HFSS 天线设计课程, 可以帮助您快速学习掌握如何使用 HFSS 设计天线, 让天线设计不再难 课程网址 :http://www.edatop.com/peixun/hfss/122.html 13.56MHz NFC/RFID 线圈天线设计培训课程套装套装包含 4 门视频培训课程, 培训将 13.56MHz 线圈天线设计原理和仿真设计实践相结合, 全面系统地讲解了 13.56MHz 线圈天线的工作原理 设计方法 设计考量以及使用 HFSS 和 CST 仿真分析线圈天线的具体操作, 同时还介绍了 13.56MHz 线圈天线匹配电路的设计和调试 通过该套课程的学习, 可以帮助您快速学习掌握 13.56MHz 线圈天线及其匹配电路的原理 设计和调试 详情浏览 :http://www.edatop.com/peixun/antenna/116.html 我们的课程优势 : 成立于 2004 年,10 多年丰富的行业经验, 一直致力并专注于微波射频和天线设计工程师的培养, 更了解该行业对人才的要求 经验丰富的一线资深工程师讲授, 结合实际工程案例, 直观 实用 易学 联系我们 : 易迪拓培训官网 :http://www.edatop.com 微波 EDA 网 :http://www.mweda.com 官方淘宝店 :http://shop36920890.taobao.com 专注于微波 射频 天线设计人才的培养易迪拓培训官方网址 :http://www.edatop.com 淘宝网店 :http://shop36920890.taobao.com