Multiple Diodes Quasi-Optical Oscillater

This paper presents quasi-optics techniques, millimeter techniques and a global optimization method etc techniques. It is a structure of quasi-optics power combiner, that includes a spherical reflection, that the radius of the curvature is R and another one is a hybrid reflector that is called input reflector. The space of the both reflectors is LL. The monolithic source-array is made up of 25 Gunn diodes that are mounted of parallel brass bars that have low thermal resistance. And the bars are fixed on the inner plane surface of the hybrid reflector. The hybrid reflector made up of a plane and a spherical, that the radius of the curvature are R. It is designed that higher fundamental mode power, larger fractional power of fundamental mode power and more combining efficiency of the quasi-optics power combiner.This paper describes an algorithm, which can determine the global optima of the power combiner of solid-state millimeter wave resonator. The global optimization method can determine a neighborhood of the global optima of an objective function and an estimation of the global optima. In the quasi-optical resonator, the objective functions are the fundamental mode power, the fractional power of fundamental mode and the combining efficiency respectively.     

Global Optimization CAD in MM Wave Waveguide Cavity

This paper describes a global optimization design for power combiner of solid-state millimeter wave source in rectangular wave- guide cavity. The algorithm can determine a neighborhood of the global optimum of an objective function. In this paper, the performance parameter are presents by combining efficiency, tuning range, frequency drift, and FM noise were done the objective functions respectively. And it is to calculate the global optima respectively.     

MMW Source CAD in Quasi-Optical Resonator

This paper presents a quasi-optical resonator that design methode basic on IBM PC computer (CAD). There is an exellent method to calculate global optima of the fundamental mode power, fractional power of the fundamental mode and combining efficiency etc. It also presents a process of CAD of microcomputer.     

A global optimization method for quasi-optics power combiner

This paper describes an algorithm which can determine a neighborhood of the global optimum of an objective function and an estimate of the global optimum.This method wasemployed to determine global optimum of the fundamental mode power, the fractional power of the fundamental mode and the combining efficiency. Given this information, a local optimization procedure can be employed to local the global optimum.Work supported by natural science fund of China.     

Global optimization design of quasi-optics fower combiner of solid-state millimeter wave resonator

This paper describes a global optimization design of quasi-optics power combiner of solid-state millimeterwave resonator. It is operated in the frequency range from 50 to 300 GHz using GaAs Gunn diodes. It is shown that sourcearrays containing N² (N=3,5,...2K+1, where k is positive integer) individual elements. It is very efficient power transfer of energy from the source-array to the fractional power of the fundamental beam mode etc.. The RF output power exceeded the sum of the individual diodes to be threefold to sevenfold. And this data is the global optimization solution.     

The design of quasi-optics power combiner of millimeter wave

This paper presents a theoretical method for design quasi-optics power combiner of solid-state millimeter — wave sources, and gives theory analysis to some problem concerned. Here is the structure:

On the extraction of harmonic power from quasi-optical solid-state power combiner

Quasi-Optical solid-state power combiner using high Q open resonator as its resonating system has high stability of frequency and can combine powers from several devices easier than other combiners. In this paper, the technique of harmonic power extraction from quasi-optical open resonator is analyzed and discussed, finally the possibility of this technique is discussed as well.     

The degenerate multimode confocal resonator

The simultaneous excitation of the fundamental and higher order radial modes in a degenerate confocal resonator leads to destructive interference between modes on the optic axis and hence reduces the power coupled by an axial iris. This mode competition may be reduced drastically by proper control of the aperture flux distribution and is of particular significance when the resonator is used for the power combining of solid-state sources.     

Millimeter wave source in the rectangular waveguide cavity

This paper describes a power combiner of solid—state millimeter wave in rectangular cavity. The operating frequency is about 50 GHz. And the sources of excitation are GaAs Gunn deodes. Final presents the performance parameter, combining efficiency, tuning range, frequency drift, and FM noise, etc. This paper also presents a millimeter wave source of rectangular waveguide cavity. Using an exellent algorithm to design rectangular waveguide cavity of power combimer. The algorithm gives the mathematial model, on the basis of the mathematial model, using CAD of PC microcomputer to design the parameters of the cavity. This paper presents a program of CAD of micocomputer.     

用于速调管功率合成输出结构的转向波导设计

 为X波段高峰值功率速调管功率合成输出结构设计了一个工作在9 GHz的转向波导，用于连接功率合成器和速调管输出腔。转向波导结构由中心矩形谐振腔、两个矩形耦合孔和两边的输入输出波导组成；输入和输出波导由速调管输出腔和功率合成器确定，分别工作在TE₁₀和TE₀₁模式，它们相互垂直并偏离矩形谐振腔的中心；中间的矩形谐振腔工作在TM₁₁₀，TE₁₀₁和TE₀₁₁混合模式。这种转向波导结构的3个反射零点构成了较宽的传输通带。将连接转向波导结构的功率合成器加载到速调管输出腔,计算了功率合成器加载后速调管输出腔的间隙阻抗。计算结果表明：功率合成器的加载对输出腔间隙阻抗影响不大。设计的转向波导结构很好地应用到了速调管功率合成输出结构中。     

Modelling a millimeter wave harmonic power combiner by a hybrid field analysis technique

A dual-diode millimeter wave harmonic power combiner in which two radial line transformers are used is modelled by a field analysis technique based on Galerkin's method combined with collocation technique. The external circuit impedances looking outside from each of two active devices are computed at both fundamental frequencies and the second harmonic frequencies. Numerical results of the impedances with respect to various structural parameters are presented. Some important characteristics of the harmonic power combiner are revealed. A number of useful conclusions have been deduced for practical design and adjustment.     

The new technique of harmonic power combination—Millimeter-wave quasi-optical harmonic power combination

In this paper, the new technique of harmonic power combination—millimeter -wave quasi-optical harmonic power combination is presented. In this technique, by compounding several closed resonators with a quasi-optical open resonator, the harmonic powers of active devices are combined, which takes effectively respective advantages of closed cavity power combination and open cavity power combination and improve the combination efficiency of multiple-device harmonic power combiner. The experimental results for W-band are given and shown this combination method is available.     

A Novel Millimeter-Wave Power Combining Circuit

This paper presents the analysis and design of a novel millimeter-wave power combining circuit. This combing circuit is composed of a new style 3-dB combiner, which achieves low-loss, wide-band, and symmetric power division. Different from conventional Wilkinson hybrid, the proposed combiner requires no isolating resistor, and is easier fabricated and more suitable for millimeter integrate circuits. Analytical and experimental work on a two-way combining circuit with wave-guide ports in Ka-band shows the combiner has an insertion loss of 0.2dB, and a power-combining efficiency above 80% in 32–33GHz is obtained.     

Analysis of Complex Dielectric Phase Gratings by Hybrid FEM-Gaussian Mode Expansion Technique

Hybrid technique of finite element method (FEM) and Gaussian mode expansion method is implemented for the analysis of transmission property of dielectric phase gratings used in holographic power combining systems. It takes advantages of the versatility of FEM and the simplicity of the mode expansion method. Apparently, this hybrid method is well suited for the analysis of phase gratings with complex profiles, which provide more degrees of structural freedom than those of classical rectangular groove gratings. The transmitted fields of an array of two and three fundamental Gaussian beams through the multi-stepped and curved gratings are calculated by the hybrid method. Numerical results show that much less phase distortion can be fulfilled for the reconstructed pseudo-plane wave by the modified phase gratings, especially the curved ones. This is advantageous for improving the combining efficiency in spatial millimeter wave and sub-millimeter wave power combining systems.     

Characteristics of millimeter wave detection in a Fabry-Perot resonator using a YBCO-BiO composite superconductor

A quasioptical technique with a hemispherical-type Fabry-Perot resonator for measuring characteristics of millimeter wave detection using a YBCO-BiO composite superconductor has been successfully developed. This Fabry-Perot resonator consists of a spherical mirror and a plane mirror mounted on the cold head of the refrigerator, under a controlled temperature of 40 to 300 K. The method offers the advantages of estimating irradiation power, easily controlling the sample temperature, analyzing the mode of the irradiated millimeter waves and easily extending to higher frequencies. The superconducting millimeter wave detector has been measured with this technique, with measured sensitivities of 46.5 V/W (70 K) to 160 V/W (35 K) at 50 GHz. These results are close to the theoretical values calculated numerically from the characteristics of the detector. It was confirmed that the millimeter wave detection system using the Fabry-Perot resonator is suitable for estimating the sensitivity of the high-Tc superconducting millimeter wave detector.     

X波段高峰值功率速调管功率合成器设计

 基于微波电路理论和EBMA(extended boundary condition model analysis)电磁计算方法，先后设计了一个工作在9 GHz的4合1和8合1功率合成器。功率合成器可将多个侧壁矩形波导中相同输入的TE10模电磁波在中心圆波导中以TE01模式输出，实现功率的合成。利用EBMA方法和CST软件对所设计功率合成器的传输系数进行了计算，在中心频率9 GHz处，计算结果分别为1.00和0.99，从而验证了功率合成器具有良好的功率合成效果。对于8合1功率合成器，还根据模型简化的想法，使得功率合成器加载后，对输出腔间隙阻抗的计算成为可能。     

Excitation of orotron oscillations at the doubled frequency of a surface wave

We study theoretically an electron frequency self-multiplier in which a surface mode of a periodic system is self-excited at a low frequency for a comparatively low current. The electron bunches, which appear as a result of this, excite the volume mode of an open resonator at the doubled frequency (coherent Smith-Purcell radiation). The open-resonator scheme allows one to obtain the higher power and coherence degree of radiation compared with the presently popular frequency multiplication scheme with an open periodic system (diffraction grating). The weakly relativistic and relativistic variants of the multipliers with a two-mirror open resonator designed for obtaining a high-power coherent radiation in the short-wavelength part of the millimeter and submillimeter ranges are studied numerically. The developed approach can also be used for designing high-power frequency multipliers on the basis of an array of nonlinear solid-state elements.     

Theory and Optimization Calculation of 3-Mirror Axisymmetric Quasi-Optical Power Combining

Very efficient power combining of solid-state millimeter wave sources may be obtained through 3-mirror quasi-optical resonators and Source arrays. The location and configuration of the source array are determined by CAD (Computer-aided design) technique.     

Broadband Analysis of Holographic Power Combining Circuits

Holography is a promising technique for power combining applications in the frequency range of short millimeter and submillimeter waves. In this paper, quasi-optical holographic power combining circuits are investigated. An equivalent network is utilized which rigorously models horn arrays and biperiodic dielectric structures in order to design computer-generated holograms. We apply the network model to a 5-element quasi-optical power combiner and demonstrate its capability. The hologram is designed for 150 GHz and has an efficiency of 92.5 % with a 90 % bandwidth of 5.3 %. With the aid of a broadband waveguide power divider and a vector field measurement system, the circuit is analyzed.