毫米波雷达四元微带双天线阵的研制

本文介绍了一种应用于收发分离体制毫米波雷达前端的小型微带阵列双天线.双天线包含两个四元并馈微带天线阵,共置于直径为18.6毫米的圆形衬底上,分别作为雷达前端的接收和发射天线.前端电路采用自行研制的毫米波雷达MMIC套片,利用MCM技术集成在与天线共型的圆形衬底上,与天线以背对背方式连接,采用小孔耦合技术进行场耦合.经过对天线和整个前端的测试,收发天线提供了10.5dB的增益,两天线问的隔离度优于-34dB,雷达前端具备良好的收发性能.     

双层宽波束天线设计

针对宽波束天线在车载雷达中的应用,突破角雷达方位面3 dB波束宽度的限制,实现微带阵列天线在水平面的宽波束覆盖,设计了一款1×10串馈微带双层结构天线。线阵单元采用道尔夫-切比雪夫（Dolf-Chebyshev）综合法电流分布来达到降低天线俯仰面副瓣的效果,在串馈阵列上方加载寄生贴片和介质基板拓展天线方位面的3 dB波束宽度。分析了双层天线展宽波束的原理,加工并实测了双层宽波束天线,其方位面的3 dB波束宽度为134.6°,增益达到10.6 dB,副瓣电平为-19.8 dB,可以满足车载角雷达天线需求。     

用缺陷地结构抑制圆极化微带天线的谐波

设计了将缺陷地结构(DGS)用于圆极化微带天线以实现谐波抑制功能。方形切角贴片激励圆极化波,50Ω微带线下的双"哑铃"型DGS实现二次谐波的抑制。天线的仿真结果和加工测试基本吻合。经测试,天线的中心频率为5.8 GHz,小于-10 dB的S11带宽为200 MHz,二次谐波频段抑制在-3.45 dB以内;天线的最大增益为6.3 dBi,波瓣前后比为13 dB,3 dB轴比带宽为70 MHz。该天线用于射频前端,可实现射频前端的小型化。     

应用于毫米波无线接收系统的高集成化LTCC AIP设计

介绍了一种基于低温共烧陶瓷工艺的新型高度集成毫米波无源接收前端,该前端由阵列天线、馈电网络和带通滤波器构成.上述无源器件以天线集成封装方式经过一体化设计,并应用于毫米波无线系统.首先,设计了2×2线极化空气腔阵列天线,通过采用新颖的内埋空气腔体结构,使天线最大增益提高了2.9 dB.其次,将具有双层谐振结构的三阶小型化发卡型带通滤波器和天线馈电网络进行一体化设计.该滤波器测试结果显示:插入损耗为1.9dB,3 dB相对带宽为8.1％(中心频率为34 GHz).最后将上述天线和滤波网络进行一体化设计,实现了三维无线接收前端.在集成结构中,通过采用金属柱栅栏抑制了寄生模式.测试结果显示天线最大增益可达14.3dB,通过集成滤波馈电网络,其阻抗带宽为2.8 GHz.该新型一体化集成前端系统具有良好的射频性能,可作为全集成无源前端应用于Ka波段无线系统中.     

一种X波段船舶导航雷达射频接收机设计

根据一种X波段船舶导航雷达的总体技术指标,研制了一款与之配套的低噪声镜像抑制射频前端接收机。整个接收机由限幅、低噪声放大、镜像抑制混频三个主要功能模块构成。在研制过程中采取由独立到集成的研制思路,在每个独立模块的性能经测试符合技术指标的基础上再进行整个接收机的集成设计及实验测试,给出了接收机的噪声及链路增益测试曲线。测试结果表明：该射频接收机在9.36 GHz~9.46 GHz频率范围内具有3.6 dB的噪声系数及2.5 dB的链路增益,镜像抑制度达到30 dB,各项性能指标均满足船舶导航雷达使用要求。整个前端模块体积小、成本低,适合民用领域的规模化生产。     

应用于毫米波无线接收系统的高集成化LTCC AIP设计

介绍了一种基于低温共烧陶瓷工艺的新型高度集成毫米波无源接收前端, 该前端由阵列天线、馈电网络和带通滤波器构成.上述无源器件以天线集成封装方式经过一体化设计, 并应用于毫米波无线系统.首先, 设计了2×2线极化空气腔阵列天线, 通过采用新颖的内埋空气腔体结构, 使天线最大增益提高了2.9 dB.其次, 将具有双层谐振结构的三阶小型化发卡型带通滤波器和天线馈电网络进行一体化设计.该滤波器测试结果显示:插入损耗为1.9 dB, 3 dB相对带宽为8.1%(中心频率为34 GHz).最后将上述天线和滤波网络进行一体化设计, 实现了三维无线接收前端.在集成结构中, 通过采用金属柱栅栏抑制了寄生模式.测试结果显示天线最大增益可达14.3dB, 通过集成滤波馈电网络, 其阻抗带宽为2.8 GHz.该新型一体化集成前端系统具有良好的射频性能, 可作为全集成无源前端应用于Ka波段无线系统中.     

一种Ku波段宽带T型相控阵天线的设计

为同时兼顾天线的电性能和成本，设计了一种 Ku 波段的宽带 T 型雷达相控阵天线， 给出了天线的分析和设计过程。天线由两个一维线阵组合而成，正交布置的两个一维线阵可在小角度范围内形成正交的双扇形波束，实现有限相扫。在满足了雷达天线扫描精度需求的同时，减少了天线单元和移相器数量，降低了天线成本。经实际测试，在 34 %的工作带宽内，单个线阵增益大于30.9 dBi。相干合成工作模式下，天线增益较单线阵增益增加约3 dB，波束宽度为1°×1°， 测试结果与设计分析具有良好的一致性。     

低雷达截面的超宽带Koch分形槽缝天线

设计了一种具有低雷达截面的超宽带分形槽缝天线。利用"突出角"为90°的Koch分形对方形槽天线进行3次迭代设计后,-10dB阻抗带宽范围由方形槽缝天线的3.0～13.1GHz变为2.8～13.7GHz。仿真和测试结果显示,天线在3GHz和8GHz方向图对称,在整个频段内相对于原天线的增益更稳定,且具有较低的雷达散射截面(RCS)。该天线适用于对超宽带天线具有低RCS要求的场合。     

基于口面场方法的W波段高口面效率单脉冲卡塞格伦天线

本文提出来一种应用于直升机防撞雷达的高口面效率W波段单脉冲双反射面卡塞格伦天线。口面分析方法的提出解决了W波段反射面天线口面相位分布不均匀的缺陷,从而有效的提高了口面的利用效率。利用该方法,本文研究并制作了口径为135mm、焦距为40.5mm的W波段卡赛格伦天线,并且设计了由四个E面多缝隙电桥和四个四分之一波导波长延迟线级联构成的和差网络。经测试,该单脉冲天线在93GHz具有38.6dBi的和波束增益,相应的口面效率为54.7%;差波束的零深优于-22dB,副瓣电平小于-18dB。测试结果与基于口面分析方法的仿真结果吻合,从而证明了本文所研究天线可以应用于高口面效率的W波段单脉冲系统中。     

RFID近场天线应用及设计方法研究

射频识别(RFID)系统在交通、物流货运、工业生产、设备监控以及服务行业等诸多领域中已经得到了广泛的应用.对近场天线的应用及设计方法进行深入研究,结合天线近场耦合原理和微带天线谐振腔模型法,提出了一种近场天线的优化设计方法,还将天线应用到电信机柜管理系统中,利用HFSS对设计出的天线进行仿真,并加以测试验证.制作出的天线经过测试,在电信机柜环境下的回波损耗在频带918～926 MHz中小于-10 dB,并且谐振于922 MHz.单根近场天线的近场场强能够覆盖电信机柜管理平面内的500 mm×300 mm的区域,并据此确定出覆盖整个电信机柜平面的天线系统的设计方案.     

A Circularly Polarized Balanced Radar Front-End With a Single Antenna for 24-GHz Radar Applications

In this paper, we propose a circularly polarized balanced radar front-end topology with a Tx leakage canceller. This radar is composed of a dual-orthogonal fed microstrip patch antenna, a 90$^circ$ delay line, a differential cross-coupled oscillator, two Lange couplers, a Wilkinson combiner, and a mixer. We implemented circularly polarized balanced Doppler radars by using a printed circuit board and InGaP/GaAs heterojunction bipolar transistor technologies. The front-end chip and module with antenna are 1 mm $times$ 1 mm and 3 cm $times$ 3 cm, respectively. The average Tx-to-Rx isolation is about 36 dB. This radar can measure speeds as low as 0.5 mm/s, which corresponds to a 0.076-Hz Doppler shift. The received signals of the circularly polarized balanced Doppler radar are about two times larger than those of a linearly polarized balanced Doppler radar due to the topology. This result occurs because the proposed radar has an intrinsic loss of only 3 dB in the receiving path.      

Development of a low-cost 35 GHz radar sensor

Two different 35 GHz low-cost rf front-end Doppler units suited for automotive applications have been constructed. The homodyne unit consists of both receiving and transmitting corporate-fed microstrip patch array antennas, a microstrip directional coupler, a monolithic GaAs fected oscillator and an integrated single Schottky diode mixer. The autodyne configuration uses only one antenna and the fected as a self-oscillating mixer. Inexpensive microstrip technology has been used which yields a good compromise between cost factor and technical performance.     

Microstrip antenna array with series-fed `through-element? coupled patches

A new microstrip antenna array with series-fed patches is proposed. To reduce the length of feeding lines the `through-element' feeding technique has been developed. A microstrip patch in which the input feeding line is directly connected and the output line is coupled to a patch is investigated. By adjusting the length of the coupling region an appropriate coupling level is achieved. A 4times1 antenna array operating within the 24 GHz frequency band for radar sensor applications is designed using the proposed feeding technique     

微带贴片阵列天线的复谐振频率和散射截面

运用无限周期结构的诸城法建立起微带阵列天线的复谐振频率和雷达散射截面公式。通过对复谐振频率和散射特性的计算分析，得出微带阵列天线的散射特性取决于它的。质因素的结论。采用。载方法。可降低耦合对微带阵列天线散射特性影响，又可减小微带阵列天线的雷达散射截面。     

An affordable millimeter-wave beam-steerable antenna using interleaved planar subarrays

Design and fabrication aspects of an affordable planar beam steerable antenna array with a simple architecture are considered in this paper. Grouping the elements of a phased array into a number of partially overlapped subarrays and using a single phase shifter for each subarray, generally results in a considerable reduction in array size and manufacturing costs. However, overlapped subarrays require complicated corporate feed networks and array architectures that cannot be easily implemented using planar technologies. In this paper a novel feed network and array architecture for implementing a planar phased array of microstrip antennas is presented that enables the fabrication of low-sidelobe, compact, beam-steerable millimeter-wave arrays and facilitates integration of the RF front-end electronics with the antenna structure. This design uses a combination of series and parallel feeding schemes to achieve the desired array coefficients. The proposed approach is used to design a three-state switched-beam phased array with a scanning width of /spl plusmn/10/spl deg/. This phased array which is composed of 80 microstrip elements, achieves a gain of >20 dB, a sidelobe level of <-19 dB and a 10-dB bandwidth of >6.3% for all states of the beam. The antenna efficiency is measured at 33-36% in X band. It is shown that the proposed feeding scheme is insensitive to the mutual coupling among the elements.     

Scanning characteristics of ferrite fed microstrip array antenna

A new ferrite fed microstrip scanning array antenna is proposed which is capable of beam scanning in the azimuthal plane as well as in the elevation plane. The antenna consists of eight microstrip arrays, each having six elements in cascade. The antenna is fed with a ferrite loaded rectangular to circular waveguide transition. The coupling between the feed system and diOEerent arrays is achieved through slots cut in the circular waveguide. Theoretical investigations of the proposed antenna exhibit a beam scanning of ±180° in the azimuthal plane with the help of dc bias and 90° in the elevation plane for ±750 MHz deviation. A scan rate of 0:06° MHz^?1 is achieved for each array antenna in the elevation plane, which makes it suitable for radar. Continuous uniform beam shift is observed during scanning.     

24-GHz Frequency-Modulation Continuous-Wave Radar Front-End System-on-Substrate

Design and implementation of a 24-GHz frequency-modulation continuous-wave radar front-end system is presented and discussed, and its hybrid planar and waveguide building blocks are fully integrated on one single substrate. A flexible and compact integration methodology on the basis of the substrate-integrated-circuits concept is deployed to design such a microwave front-end system-on-substrate. In this study, it is found that this surface-volume hybrid integration scheme not only enables the complete system integration of planar and nonplanar microwave circuits, but also combines respective advantages of such structures in connection with microstrip lines (planar) and waveguides (nonplanar). Design strategies of the system building blocks including mixers, power dividers, and antenna arrays are discussed together along with the measured results. To verify the developed radar prototype, laboratory-based target-range measurements are conducted.     

中远程一体化车载雷达线阵天线的设计

该文提出了一种新型的宽带近接耦合毫米波微带阵列天线,并将其作为77~81 GHz中远程汽车雷达的专用天线。该天线阵列由微带线及一系列矩形和多边形辐射单元组成。辐射单元在微带线两侧呈周期性分布,间隔约为引导波长的1/2。为增强激励耦合引入了矩形和多边形辐射单元,在拓宽阻抗带宽的同时,抑制了带外频率。不同辐射单元和矩形反射槽相匹配,达到波束赋形的效果,实现了平肩膀辐射方向图。通过调整辐射单元与微带线的间隔,控制辐射单元的归一化电阻。在工作频率为77~81 GHz时,阵列天线的增益超过14 dBi,阻抗带宽达到7.47%(76.5~82.4 GHz)。对实物样本进行加工及性能检测,测试表明,仿真与实测数据基本一致。