Planar Miniature RFID Antennas Suitable for Integration With Batteries

A class of planar, electrically-small UHF antennas suitable for direct integration with electronic components such as batteries is introduced. The new design approach combines a meander line section and a capacitive strip section. The geometries of the two sections can together be scaled in size over a wide range of planar form factors while still maintaining self-resonance and practically realizable line widths and spacings. No external matching network is required. Moreover, batteries can be mounted above or below the capacitive strip section, significantly reducing the total size of a wireless device. Three designs are demonstrated on printed circuit board at 433 MHz. Measurements show that the antennas provide good gain and excellent bandwidth, omnidirectional radiation patterns, and electrically small size. The results of this work have numerous uses in radiofrequency identification (RFID)     

Communication Using Antennas Fabricated in Silicon Integrated Circuits

The feasibility of integrating compact antennas and required circuits for implementing wireless interconnections in foundry digital CMOS technologies has been demonstrated. A 3-mm long zigzag dipole antenna on a 20-Omega-cm substrate should have efficiency up to approximately 25% at 24 GHz and cost 1-2 cents. These antennas can be used to implement a radio for 100-kb/s communication up to about 10 m. By lowering the operation frequency to 5.8 GHz and using a monopole structure, which occupies approximately 30% more area, the communication range can be increased by three times or more. This technology, as well as in a true single-chip radio, can be used for intra- and inter-chip data communication, intra- and inter-chip clock distribution, beacons, radars, RFID tags, and contactless high-frequency testing.     

Analysis of Planar Ultrawideband Antennas With On-Ground Slot Band-Notched Structures

Planar ultrawideband (UWB) antennas with on-ground band-notched structures are studied in this paper. Two different slot resonators, which feature quarter-wavelength and half-wavelength configurations, are embedded into the arc shaped ground plane of the circular disk patch antennas in order to obtain the desired band-rejection around 5.8 GHz. Their principles and characteristics are analyzed and compared in detail providing designers with in-depth understanding and useful design information. By choosing the quarter-wavelength slot resonator, the first spurious stopband can be pushed up to 3 $f _{0}$ ($f _{0}$ stands for the center frequency of the notch) and this antenna retains a super wide working band which spans from 1.62 GHz to 17.43 GHz. Performance in both the frequency domain and time domain for this antenna has been investigated carefully. The transmission response of a transceiving antenna system and their corresponding transient analysis are discussed at the end of this paper.      

Dual-Polarized Microstrip Patch Planar Array Antennas With Improved Port-to-Port Isolation

A method of preventing the degradation in the isolation between the orthogonal polarization ports caused by beamforming network routing in combined edge/aperture fed dual-polarized microstrip-patch planar array antennas is described. The simulated and measured performance of such planar arrays is demonstrated. Measured port isolations of 50 dB at center frequency, and more than 40 dB over a 4% bandwidth, are achieved. In addition, insight into the physical reasons for the improved port-to-port isolation levels, of the proposed element geometry and beamforming network layout, is obtained through prudent use of the electromagnetic modelling.      

Integration of a Microstrip Circulator With Planar Yagi Antennas of Several Directors

An integration methodology is presented to design antenna systems incorporating a ferrite circulator. Two integrated systems comprised of a microstrip circulator and Yagi planar–type antennas are presented as validation of the proposed methodology. Excellent pass band characteristics are observed in the experimental and numerical data for both systems. Furthermore, one system is magnetically tuned to realize 30 dB isolation over a bandwidth of 850 MHz. Both systems maintain excellent return loss and show improved insertion loss specifications even though the ferrite is biased into partial saturation. Extensive measurement data of the ferrite material and system network parameters are provided to corroborate the claims made herein.      

平面单极天线的设计

随着SDR(软件无线电)和UWB(超宽带)无线系统对宽带天线的需求,平面单极天线渐渐成为研究的热点,它具有频带宽、体积小、制作简单、成本低等诸多优点。首先给出了平面单极天线的应用场合;然后阐述了该天线的设计方法,包括天线的四种形式、最佳馈电点间隙的选择和对称切角天线馈电点的处理;其次给出了天线设计时的边长选择,切角度数的选择和不同材料的比较;最后做了总结并提出了今后的研究方向。     

An Effective NF-FF Transformation Technique With Planar Spiral Scanning Tailored For Quasi-Planar Antennas

An effective probe compensated near-field—far-field transformation technique with planar spiral scanning is developed in this paper. It makes use of an ellipsoidal modelling of the source, instead of the previously adopted spherical one. Such a modelling, tailored for quasi-planar antennas, allows one to consider measurement planes at a distance smaller than one half the antenna maximum size, thus reducing the error related to the truncation of the scanning surface. Moreover, it is quite general, containing the spherical modelling as particular case, and reduces significantly the number of the needed near-field data when dealing with quasi planar antennas. Some numerical tests, assessing the accuracy of the technique and its stability with respect to random errors affecting the data, are reported.      

小型平面超宽带天线的研究进展

对小型平面超宽带(UWB)天线的研究现状进行了分析总结.首先介绍超宽带无线通信的技术背景,描述了超宽带天线的几种常见定义.然后分别对小型超宽带印刷单极子天线的设计、小型超宽带缝隙天线的设计、具有陷波功能的小型超宽带天线的设计进行了详细的评论,并讨论了超宽带天线的性能评价方法.最后展望了小型平面超宽带天线的未来研究方向.     

An Integrated Switching DC–DC Converter With Dual-Mode Pulse-Train/PWM Control

This brief presents an integrated switching converter with a dual-mode control scheme. A pulse-train (PT) control employing a combination of four pulse control patterns is proposed to achieve optimal regulation performance under various operation scenarios. Meanwhile, a high-frequency pulsewidth modulation (PWM) control is adopted to ensure low output ripples and avoid digital limit cycling in steady state. The converter was fabricated with a 0.35- $muhbox{m}$ digital CMOS n-well process. The entire die area, including the on-chip pads and power devices, is 1.31 $hbox{mm}^{2}$ . Experimental results show that, in the steady state, the output voltage is well regulated at 1.5 V with $pm$12.5-mV ripples in the PWM mode. The measured maximum efficiency is 91%, and the efficiency stays above 70% within the entire 500-mW power range. In transient measurements, with a 100% load step change from 50 to 100 mA, the output voltage of the converter settles within 345 ns due to the fast response of the PT control, with a maximum voltage variation of 164 mV. The converter functions well when the input supply voltage frequently varies between 2.2 and 3.3 V, with a line regulation of 29.1 mV/V.      

平面天线的发展与展望

本文综述了现代平面天线的主要型式、发展及应用趋势,并阐述平面天线在研制中的主要关键技术问题,探讨可能的解决途径.文中介绍了最新研究成果及亟待解决的课题.     

平面双频单极天线研究

研究了一种小型化的平面双频天线,利用一个斜F加倒L图形结构并通过在天线结构中的电感平衡加载来设计一种平面单极双频天线.它具有接地板小且天线低端谐振点频带宽的特点,为平面双频单极天线的小型化设计提供了一种新的方案.     

平面扇形天线的宽带特性分析

从电流分布和输入阻抗方面对平面扇形天线特性进行了描述,并具体分析了对称结构和非对称结构平面扇形天线的宽带特性。     

WLAN平面天线研究

对一种小型的平面倒F天线进行了研究,根据WLAN 802.11b/g无线通信的需求设计出一种工作于ISM 2.4 GHz频段的小型平面倒F天线。该天线面积小,约为13.5 mm×5.5 mm,能方便地集成在Cardbus卡上,降低射频前端的成本。天线的设计采用了Agilent的ADS2004仿真工具,并给出了该天线的测试方法以及测试结果。     

A Single-Chip Ultra-Wideband Receiver With Silicon Integrated Antennas for Inter-Chip Wireless Interconnection

A single-chip ultra-wideband (UWB) receiver was developed using 0.18 mum CMOS technology, and inter-chip wireless data communication by integrated antennas was confirmed. Timing pulse and data pulse with on-off keying were alternately sent from a transmitting antenna. Double Gaussian monocycle pulse (GMP) template generators performed detections of timing and data pulses. A single GMP template, whose probability distribution of the pulse repetition cycle is given by Gaussian, showed a random jitter of 4.87 ps. Dual-Dirac model could explain the probability distribution of the cycle of double GMP template. Obtained random jitter and deterministic jitter were 4.6 ps and 14.4 ps, respectively. The receiver successfully recovered 200 Mbps data at the distance of 0.5 mm.     

超宽带平面天线中实现频带抑制的方法

随着超宽带平面天线的研究和广泛应用,在超宽带天线中实现对其他无线通信设备特别是WLAN设备的干扰抑制成为研究热点。从不同结构的超宽带平面单极子天线实现频带抑制的方法出发,研究实现频带抑制的基本原理和常用方法。研究成果对超宽带天线的设计和频带的抑制具有一定的指导作用。     

平面一体化集成Ka频段卫星通信终端ODU设计

介绍了一个Ka频段卫星通信终端室外单元(ODU)的平面一体化集成设计技术.通过采用电路和结构的平面一体化集成技术、整体水密性设计和基于热仿真的散热优化设计,实现了设备的小型化、轻重量和低功耗.最终完成了两套样机研制.测试样机的技术指标满足设计要求,发射功率大于33 dBm,噪声系数小于2.4dB(常温),体积小于130...     

Monolithically Integrated Corporate-Fed Cavity-Backed Antennas

A Ka-band monolithically integrated 4 times 1 corporate-fed cavity-backed patch antenna array is demonstrated in this paper. A single antenna element has four slits introduced to extend the bandwidth to about 8%. Its gain and radiation efficiency are 6.3 dBi and 97%, respectively. A rectangular mu-coaxial line based combining network is monolithically integrated with radiating elements in a slightly modified tile configuration. Specifically, to reduce the array footprint power dividers are aligned along the array axis. Combining network has height 1/2 that of the array and feed lines do not route through the antenna elements. Overall loss of the combining network is 0.5 dB at 30 GHz. Measured reflection coefficient bandwidth and maximum gain of the fabricated 4 times 1 corporate-fed array are 13.7% and 12.73 dBi, respectively. The array is designed and fabricated in a recently developed surface micromachining process known as PolyStrata.     

Dual-Mode Dual-Band Filter With Band Notch Structures

A novel approach for designing dual-mode dual-band bandpass filters is proposed and experimentally studied. By embedding a pair of slits in the square patch, the dual-band response is realized and one transmission zero is introduced between the two passbands. Two degenerate modes are achieved by loading with a small square perturbation, which can be placed at the diagonal line. There are three transmission zeros. The slits control the first and third transmission zeros. On the other hand, the right crossed slots control the first and the second transmission zeros.      

CDMA与TACS双模式蜂窝移动通信系统

本文分析了 CDMA 与 TACS双模式蜂窝移动通信系统信道分配的一些原则,并给出了在中国当前情况下信道分配的可行方案。本文还对双模式手机的结构进行了分析。     

Conformal Antennas on Liquid Crystalline Polymer Based Rigid-Flex Substrates Integrated With the Front-End Module

Recent developments in liquid crystalline polymer (LCP)-based processing technology have shown that highly-integrated, fully-packaged radio-frequency (RF) front-end modules with high-performance can be designed by using the system-on-package (SOP) approach. However, the direct integration of a large antenna element to a small module package still remains an issue. This paper presents a novel conformal antenna structure, which results in a compact integration of the antenna and the module package for 5 GHz WLAN/WiMAX applications. The extension of 5 GHz single-band operation to 2.4/5 GHz dual-band operation is also discussed in this paper. The antenna is an inverse L-shaped monopole printed on a 25-$mu{hbox {m}}$-thick flexible LCP layer, which protrudes from a rigid multilayer organic substrate. The shielding effects of a grounded metal case, which can house the associated module circuitry, are also considered during the design process. The metal case serves as a vertical ground plane for the antenna in addition to protecting the module circuitry from the near-fields of the antenna. The flexible LCP substrate can be bent and folded over the module case, resulting in a compact design and the tight integration of the antenna with the front-end module. The details of the design and the fabrication of the proposed structure as well as the simulation and the measurement data are presented in this paper.