A new dielectric grating antenna at millimeter wave frequency

The development of a dielectric grating antenna at K/sub a/ band is presented. The antenna performance is analyzed using perturbation analysis and a numerically based commercial software. The effect of the grating profile and various dimensions on the performance is presented. Based on the analytical results a rectangular profile grating antenna is designed. The antenna is optimized, fabricated and measured. Close agreement between the simulated and measured results is obtained.     

An NRD-fed dielectric rod antenna for the short millimeter wave band

A simple E-plane tapered rectangular dielectric rod fed by NRD guide is used as a millimeter wave antenna. This class of aerial features attractive radiation patterns with relatively low sidelobes and moderate gain. The measured results show that such an antenna and mounting structure can be exploited as effective radiating element in the short millimeter wave frequency band.     

Design of layered ridge dielectric waveguide for millimeter and sub-millimeter wave circuits

Design rules for Layered Ridge Dielectric Waveguide (LRDW) are presented for the first time through simple figures and closed form equations. The Effective Dielectric Constant (EDC) method is used to develop the design rules that account for typical circuit specifications such as higher order mode suppression, dispersion, attenuation, and coupling between adjacent transmission lines. Comparisons between the design of LRDW, image guide, and millimeter-wave dielectric ridge guide are made.     

A leaky-wave antenna in nonradiative dielectric waveguide

A leaky-wave mechanism in a nonradiative dielectric (NRD) waveguide is described. The antenna used in the analysis consists of a long slot in one ground plane of the NRD guide; the currents present in the side walls cause the slot to radiate as a traveling-wave antenna. The antenna was designed to operate at 9.5 GHz to reduce the costs involved in working at high frequencies. The analysis of the slot follows the procedure outlined by L.O. Goldstone and A.A. Oliner (1959). A simple expression for the amount of coupling from the guide is derived under certain assumption made because information on the reactances necessary to model the slot is not as yet available. The theoretical coupling values verified by measurement and the design, construction, and performance of both leaky-wave antennas are described     

An NRD fed dielectric rod antenna for the short millimeter wave band

A simple E-plane tapered rectangular dielectric rod fed by NRD guide is used as a millimeter wave antenna. This class of aerial features attractive radiation patterns with relatively low sidelobes and moderate gain. The measured results show that such an antenna and mounting structure can be exploited as effective radiating element in the short millimeter wave frequency band.     

A compound high power millimeter wave waveguide circulator

In this paper, a high power millimeter wave waveguide Y-junction circulator, which is compound in structure, has been analyzed and developed. Its enduring power attains 60 W CW-power and the temperature of the waveguide surface does not exceed 25 degree centigrade under natural coolness.     

Generation of millimeter wave Gaussian beams and their propagation in a dielectric waveguide

Linearly polarized fundamental mode Gaussian beams were generated and coupled to a hollow circular oversized dielectric waveguide by placing the waist of the beam at the guide entrance. The transmission properties of the waveguide were characterized as a function of frequency for a variety of coupling conditions. These conditions included changes in the input beam waist radius, angle of incidence, and displacement perpendicular and parallel to the guide axis. It has been found that: 1.) power transmission is maximized when the waist of the input beam is centered at the guide input, injected normally, and has a radius of 0.43 times the waveguide radius, 2.) power transmission decreases rapidly with increasing angle of incidence and the rate of that loss increases with frequency, 3.) the waveguide preserves the linear polarization of the input beam, 4.) power transmission in the fundamental waveguide mode is not greatly affected by moderate displacements in the input beam position, and 5.) upon exit from the waveguide the launched EH₁₁ mode propagates as a fundamental mode Gaussian beam in the quasi-far field. The results compare favorably to the transmission theory of Belland and Crenn and approximately to the near and far field mode pattern theory of Degnan.     

Computer aided design of inverted strip dielectric waveguide millimeter wave ring-resonator and coupler

A computer aided design technique has been developed for the design of millimeter-wave ring resonator and hybrid-ring coupler using inverted strip dielectric waveguides. The scattering matrix analysis for hybrid-ring coupler has also been developed. Numerical results for these components at f₀=80 GHZ with 3-dB coupling have been presented along with the variation of width, spacing, and radii with frequency.     

A large antenna array for millimeter wave propagation studies

An antenna array has been constructed for reception of line-of-sight, ground-to-ground transmissions at 35 GHz over a 28-km path. It measures, individually, the amplitude and the relative phase of the arriving wave at each of eight antenna elements spaced horizontally over a distance of 24 m transverse to the path. Preliminary observations have shown perturbations in amplitude which appear at one end of the array and progress sequentially in a matter of seconds from element to element across the array. Similar traveling perturbations occur in the phase measurements. Variations in tilt of the wave front are observed, usually amounting from a few to tens of seconds of arc. In addition, changes in wave-front curvature have been measured corresponding to an apparent shrinkage or expansion of path length on the order of ten percent. Other capabilities of the array as a propagation-research tool are mentioned.     

Integrated travelling-wave antenna for nonradiative dielectric waveguide

A travelling-wave antenna for integrated use in nonradiative dielectric waveguide is described. The antenna is constructed by cutting a longitudinal slot in the waveguide side wall. Results are presented showing the comparison between measured and calculated data.     

毫米波通信二维有源相控阵天线简

本文围绕瓦式毫米波通信二维有源相控阵天线的总体架构、关键技术和实现途径等展开设计,在简要介绍国外相关技术和其它有关案例基础上,根据总体设计出发提出瓦式相控阵天线的设想,包含模块组成及技术实现的途径,有一定的实际可操作性,当然很多详细设计需专题仿真,但设计思想可作为未来小型化高集成的瓦式二维毫米波相控阵天线技术的尝试。     

毫米波微带天线阵列设计

设计了一个圆口径串并联混合馈电的毫米波微带天线阵列。该天线采用矩形微带工字型缝隙贴片耦合馈电的方法展宽带宽。为了有效利用天线口径面积,减小网络复杂度,选取串联微带天线阵列形式。同时为了展宽带宽,根据设计的圆形口径阵列,将部分子阵采用串并联混合馈电的形式,得到带宽为5%的毫米波微带天线阵列。仿真表明,该天线在工作频带内增益大于30.6 d Bi,波束宽度为4.0°×3.5°,副瓣电平低于–13 d B。该天线阵面与网络配合,可以实现多波束或相控阵的功能。     

Dielectric ribbon waveguide: an optimum configuration forultra-low-loss millimeter/submillimeter dielectric waveguide

Dielectric ribbon waveguide supporting the _eHE₁₁ dominant model can be made to yield an attenuation constant for this mode of less than 20 dB/km in the millimeter/submillimeter-wavelength range. The waveguide is made with a high-dielectric-constant, low-loss material such as alumina or sapphire. It takes the form of thin dielectric ribbon surrounded by lossless dry air. A detailed theoretical analysis of the attenuation and field extent characteristics for the low-loss dominant _eHE₁₁ mode along a ribbon dielectric waveguide was performed using the exact finite-element technique as well as two approximate techniques. Analytical predictions were then verified by measurements on ribbon guides made with rexolite using the highly sensitive cavity resonator method. Excellent agreement was found     

A 5-frequency millimeter wave antenna for a spaceborne limbsounding instrument

Several spaceborne Earth observation missions such as the European Space Agency's (ESA) atmospheric chemistry instruments Millimeter wave Acquisitions for Stratosphere/Troposphere Exchange Research (MASTER), Soprano or Piramhyd require the development of complex millimeter and submillimeter wave range spectroradiometers. These instruments place stringent requirements on antenna electrical performance due to the low-noise signal levels and the high-vertical resolution involved. This paper focuses on the electromagnetic (EM) design and analysis of a 2.2-m diameter Cassegrain antenna operating in 5-frequency bands between 200 and 500 GHz. The primary feed network is an essential part. It has to provide not only the low-loss frequency separation of the bands but also the antenna illumination with nearly perfect amplitude and phase patterns for high-beam efficiency. Quasi-optical techniques are extensively used for the overall antenna design and focal plane demultiplexer breadboarding and testing     

Shielded rectangular dielectric wave guides for millimeter wave integrated circuits

The dispersion characteristics of Insulated non-radiative dielectric guides are computed using mode matching technique. From the dispersion characteristics the dielectric loss conductor loss and wave impedances are derived. Effect of metallic walls on trapped insulated image guide are also discussed. The dimensions of Insulated non radiative dielectric guide are same as that of rectangular metallic wave guide at ka band.     

Reflection of millimeter waves by a corrugated dielectric slab waveguide

The TM wave propagation in a corrugated dielectric slab has been studied using a singular boundary perturbation procedure, which is supported subsequently by experiments in the millimeter-wave region.     

一种应用于毫米波波段的基片集成波导滤波器

提出了一种工作于毫米波波段的基片集成波导滤波器,该滤波器在上下金属层刻蚀出哑铃槽结构,通过哑铃槽之间的耦合,极大提高了其带外抑制性。仿真实测结果表明,滤波器的中心频率在30 GHz,通带内相对带宽为39.5%,中心频率插入损耗为1.44 d B,带内回波损耗大于13 d B。滤波器带外衰减陡峭,结构紧凑,实测结果与仿真结果吻合良好。     

一种用于毫米波的共面波导间的宽带互联结构

在多芯片组件中,微波传输线间一般使用金丝键合的方式进行连接。受金丝自身的等效电感和其与基板及壳体间存在的寄生电容的影响,键合金丝结构在毫米波频段下带来了较大的阻抗失配。为了解决该问题,文中从等效集总元件角度出发,对阻抗变换公式进行了推导,分析得出串联低阻抗传输线可以等效为并联集总电容的结论,可以与键合金丝的等效模型一起,构成等效低通滤波器,完成阻抗匹配。文中使用共面波导结构制作了键合金丝匹配结构测试件,测试结果显示,在30～40 GHz内S_(11)<-20 dB、S_(21)>-0.2 dB,具有优良的传输性能。该结构具有较强的实用性,可以用于毫米波频段下的微波组件设计。