圆形有源介质F－P腔的横模分析

利用有源增益薄片近似代替有源腔中的增益介质和采用Ｆｏｘ－Ｌｉ迭代法，我们获得了微型ＤＰＬ的圆形有源介质Ｆ－Ｐ腔的模模模型，同时还分析了腔稳态场的振幅和相位分布分别受腔的菲涅耳数Ｎ和非饱和增益增量△Ｇ影响的情况。数值计算结果与文献报道的实验情况比较一致。     

Excitation of Higher Order Modes in Spherical Cavities

An analysis for determining approximately the optimum position of the exciting source inside a spherical cavity for exciting any TE or TM mode is presented. For any TE or TM mode the orientation of the exciting probe or loop is determined by maximizing the surface integral of /bar H/ or line integral of /bar A/ which is proportional to the excitation coefficient for the corresponding mode. Specific examples of mode discrimination by proper orientation of the exciting source are also included in the paper. Besides, graphs of the surface integral of /bar H/ and the line integral of /bar A/ for various modes are presented to indicate the variation of mutual inductance for any mode, for different positions of the exciting source.     

Fabry-Perot Resonator Antenna

Fabry-Perot Resonator (FPR) antennas have attracted significant attention in microwave and millimeter waves due to a number of attractive properties, such as low complexity, high directivity and conformal deployment capability. In this paper, a summary of recent publications on FPR antenna is presented focusing on the different capabilities, technologies and architectures that have been proposed. Several structures, analytic models and research developments and a corresponding comparison are also made. It shows that such analytic models as FP cavity model, EBG defect model, transmission line model, leaky wave model and refractive lens model are consistent when applied to analyze this type of resonator antenna. Some interesting topics under recent research are surveyed in detail. At the same time some attractive topics to be further researched are also pointed out. Recent works of the authors are also included in this paper.     

Observation and Application of High-Order Azimuthal Modes in a Fabry-Perot Resonator (Short Papers)

High-order azimuthal modes (p = 0, l> 20) were excited at 10 GHz in a Fabry-Perot resonator. The energy of these modes is distributed in a ring around an energy-free central axis, which lends itself to safety applications on rotating machinery and in measuring density profiles of cylindrical plasmas.     

Plasma Diagnostics with a Microwave Fabry-Perot Resonator

Plasma diagnostics with a confocal spherical mirror Fabry-Perot resonator are examined. The diagnostic equations are presented and experimentally verified. The measurable ranges of electron densities and collision frequencies are treated both theoretically and by example. A brief background of the theory of the resonator is summarized (with references) from the literature. A perturbational technique for measuring collision frequency, or Q change, through the variation of a resonator's transmission coefficient at resonance (for a general resonator) is derived, and the results experimentally verified. This technique could be a powerful diagnostic tool and is shown to have certain advantages under noisy conditions. This type of resonator is simple and inexpensive to construct, easy to align, and gives very good diagnostic results.     

Complex Gyrator Circuits of Planar Circulators Using Higher Order Modes in a Disk Resonator

Tire use of resonators or waveguides utilizing higher order modes is often an attractive solution to the design of millimeter microwave networks. This paper investigates the complex gyrator circuit of a planar junction circulator employing higher order solntions in a disk resonator. The first such solution displays many of the features of weakly magnetized junctions using the dominant mode in a disk resonator, but its loaded Q-factor is incompatible with the realization of quarter-wave coupled devices. Although the second one exhibits more useful equivalent circuits, it requires a relatively large magnetization, which is not altogether practical at millimeter frequencies. A circulator configuration that has a frequency response akin to that of a quarter-wave coupled one is one where the in-phase eigennetwork is degenerate with those of the demagnetized counter-rotating eigennetworks. The degeneracy between the in-phase limit, TM/sub 2, 0, -2/ and the second-order counter-rotating limit, TM/sub 1, 1, -2/ modes, in an oversized irregular hexagonal resonator, is used in this paper to construct such a device.     

Perturbation Theory Generalized to Arbitrary (p,l) Modes in a Fabry-Perot Resonator (Letters)

The first-order perturbation calculation that was carried out to include the effects of the usually neglected delta/sup 2/psi / delta z/sup 2/ term in the wave equation for pure radial modes (l = 0) is generalized to the case of arbitrary p,l modes. The result, although requiring more algebra, is similar to that of the l= 0 case; the correction term is a monotonically increasing function of both p and l, and reduces to the original expression as l --> 0.     

Spherical Mirror Fabry-Perot Resonators

An experimental investigation of the Fabry-Perot interfometer (FPS) using spherical mirrors is reported. The FPS was operated as a microwave resonant cavity at 60 to 70 Gc. Measurements were made of the loss and coupling as a function of mirror spacing. The electric field variation within the resonator was also measured. Other characteristics of the spherical Fabry-Perot resonator were observed and are discussed. A qualitative discussion of the behavior of a spheroidal cavity resonator is presented and its relation to the FPS and beam waveguide is demonstrated.     

Fabry-Perot谐振天线研究综述

Fabry-Perot谐振天线自提出以来,在微波和毫米波频段得到了广泛的应用,引起了国内外许多学者地重视,并取得了一些研究成果,已逐步成为国际上一个比较新的研究热点.文中对Fabry-Perot谐振天线的结构、理论分析模型、研究动态等有关问题进行了比较详实的分析和综述,指出了几种理论分析模型在分析此类谐振天线时的一致性,提出了FabryPerot谐振天线可以看作是EBG谐振天线的一个特例.同时对目前此类天线的主要研究方向进行了归纳与总结,并指出了有待研究的方向.     

宽带介质覆层Fabry-Perot 谐振腔天线设计

结合传输线理论和史密斯圆图分析,文中提出了一种利用全介质部分反射覆层构造宽带Fabry鄄Perot 谐振腔天线的方法。所设计的覆层结构在工作频带内拥有正斜率的反射相频特性,可满足谐振腔天线的宽带谐振条件。运用该方法设计了工作于Ku 频段的宽带Fabry鄄Perot 谐振腔天线,通过仿真计算和样件加工测试验证了该方法的正确性和有效性。     

HTS 毫米波介质谐振器高阶模耦合计算

本文主要分析计算８ｍｍＨＴＳ（Ｈｉｇｈ Ｔｃ Ｓｕｐｅｒｃｏｎｄｕｃｔｏｒ）膜ＴＥ０１３高阶介质谐振器的耦合过程。通过采用ＨＴＳ膜的实验装置对计算模型进行验证,表明理论计算可以给出正确的参数变化趋势。由于ＨＴＳ的交流电阻接近零的效果,外电路的Ｑｏｕｔ值和耦合系数的变化均非常敏锐,说明了采用ＨＴＳ的高阶模介质谐振器,比一般谐振器对耦合的灵敏度高,ＨＴＳ介质谐振器的理论计算Ｑ值可达到１０＾６以上。     

Measurements of Dielectric Properties at Ka-Band Using a Fabry-Perot Hemispherical Open Resonator

A Fabry-Perot hemispherical open resonator is designed and constructed in order to measure dielectric properties of BeO in the Ka-band (26 – 40 GHz) frequency range. Based on both analytic calculations and simulations by a 3-D finite element electromagnetic code, HFSS, the hemispherical open resonator is designed to excite a TEM_0,0,17 mode at 28 GHz. The TEM_0,0,17 mode is experimentally identified by a field perturbation technique. Dielectric measurements are made by both frequency variation and length variation methods. Measurements show that permittivity and loss tangent of BeO are 6.69 and 6.5 × 10^?4 - 7.2× 10^?4, respectively, in the frequency range of 26 – 34 GHz.     

Optical Analog-to-digital Conversion Scheme Based on Tunable Fabry-Perot Resonator

Proposed is an interference type of optical analog-to-digital conversion(ADC). The refractive index of Fabry-Perot cavity changes with different voltages. The Fabry-Perot resonator converts electronic intensity into light wavelength through selecting lights of different wavelengthes. The parameters of the scheme are acquired with the transmission matrix of optical element and the time of steady-state light field. The maximum sampling speedes of 4-bit, 6-bit, 7-bit, 8-bit and 9-bit(ADC) are 1.695×1010 count/s, 4.33×109 count/s, 2.38×109 count/s, 1.24×109 count/s and 5.9×108 count/s, respectively.     

Stable and Unstable Spatial Modes in a Resonator with a Half-Disk Shape

Semiconductors - This work was devoted to the study of stable and unstable optical modes in segment shaped resonators. The size of the studied resonators was much larger than the wavelength of the...     

Modes and Instabilities of Modes of the Flat-Roof Open Resonator

The problem of modes and losses of a resonator terminated by "flat-roof" reflectors is approached with the Fox and Li method of iteration. Field distributions, phaseshifts, and losses for some of the low-order modes are derived as functions of the roof angle and mirror aperture. A good agreement is found with the approximate theory previously developed by Toraldo di Francia. High loss regions are also observed. The behavior of different modes in such regions is investigated in detail. Design guidelines are given too. Experimental texts carried out on an X-band model confirm the theoretical predictions.     

The Coupling of a Single-Ridge Waveguide to a Fabry-Perot Resonator (Short Papers)

The functional forms of the fields in a single-ridge waveguide are presented. Bethe's small-hole diffraction theory is used to determine the coefficient for coupling from various parts of the guide to a Fabry-Perot (FP) resonator. It is shown that frequency-independent coupling over a very broad band is possible, and specific examples are given for the band from 18.0 to 40.0 GHz.     

Dielectric Measurements of CVD Diamonds at Millimeter Wavelength Using a Fabry-Perot Open Resonator

Precise dielectric property measurements at a millimeter wave frequency band are attractive. A Fabry-Perot open resonator consisting of hemispherical and plane mirrors, coupling holes is designed by the use of analytic theories and a numerical simulation code. HFSS. Dielectric constant measurements on CVD diamonds are performed by a frequency variation method. Measurements show that permittivity and loss tangent range from 5.59 to 6.46, and from 1.1 × 10^?3, to 5.3 × 10^?2. respectively, in the frequency range of 95–100 GHz depending on sample preparation of the CVD diamonds.