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.     

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.     

A new kind of compound solid-state quasi-optical power combiner

In this paper, a new kind of solid-state quasi-optical power combiner is presented. It consists of two or more singlecavity multiple-device power combiners and a Fabry-Perot cavity. The experimenal results using six Gunn diodes at X-band show that the total output power is higher than 400 mW, the total combining efficiency is as high as 83%, and the frequency stability is better than 10^–5.     

Design of Low-Profile Millimeter-Wave Substrate Integrated Waveguide Power Divider/Combiner

A low-profile millimeter-wave substrate integrated waveguide (SIW) power divider/combiner is presented in this paper. The simplified model of this compact SIW power dividing/combining structure has been developed. Analysis based on equivalent circuits gives the design formula for perfect power dividing/combining. In order to verify the validity of the design method, a four-way SIW power divider/combiner circuit operating at Ka band is designed, fabricated and measured. Good agreement between simulated and measured results is found for the proposed passive power divider/combiner. Experiments on the four-way passive divider/combiner back-to-back design demonstrate a minimum overall insertion loss of 1.5 dB at 31.1 GHz, corresponding to a power-combining efficiency of 84%. The measured 10-dB return loss bandwidth is demonstrated to be 2.2 GHz, and its 0.5-dB bandwidth was 2 GHz.     

Analysis on radial field of quasi-optical power combiner using complex source point theory

A uniform high-frequency solution is presented for the diffraction by a dielectric spherical mirror by a Gauss beam. Using the complex source-point theory, the radial field of quasi-optical power combiner is obtained. The E or H plane patterns of the combiner are calculated.     

A method for designing a variable-channel high-power cavity combiner

Cavity combiners have been put forward for high power combining due to their advantages of larger combining ability,variable input channels and less power loss.For a high power cavity combiner,it is better to keep the power loss ratio in a reasonable range,because large power loss would lead to strict requirements on the cooling system.A combiner with variable input channels is convenient for outputting different power levels according to practical demands.In this paper,a method for designing a variable-channel high-power cavity combiner is proposed,based on the relation between input and output coupling coefficients obtained by analyzing the equivalent circuit of the cavity combiner.This method can put the designed cavity combiner in a matching state and keep its power loss rate in a reasonable range as the number of input channels changes.As an example,a cavity combiner with 500 MHz and variable input channels from 16 to 64 is designed,and the simulation results show that our proposed method is feasible.     

Discussion of the source-array plane location in the quasi-optical cavity for solid state power combining

A quasi-optical power combiner operating in millimeter-wave with lumped parameters source-array is described. The location and corfiguration of the source array are determined.     

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.     

Millimeter Wave Power Combiner Based on a Half-Open Resonator

Experimental investigations of quasi-optical power combiner based on a half-open resonator are described. Power and frequency characteristics have been studied for one or three diodes. It is shown that the positioning of the diodes is preferred over the center of the field spot along a resonator axis.     

Global optimization method in millimeter wave 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 mehtod can determine a neighborhood of the global optima of an objective function and an estimation of the global optima. In this paper the objective function as follow: In the quasi-optical resonator, the objective function are the fundamental mode power, the fractional power of fundamental mode and the combining dfficiecy were done the objective functiona respectively, to calculate the global optima respectively. In the power combiner of solid-state millimeter wave source in rectangular waveguide cavity. the performance parameter are presentes by combining efficiency, tuning range, frequency drift, and FM noise were done the objective functions respectively. And to calculate the global optima respectively.     

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.     

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.     

基于二维Meniscus透镜的准光功率合成器

为了实现大功率容量和高效率的空间功率合成,将基于波导腔体的二维Meniscus透镜用于毫米波功率合成器的设计.对透镜中传输的主模(TE10波)的散射效应进行了分析,并且设计了匹配层减小透镜结构带来的反射.在30 GHz频率上利用Rexolite介质的Meniscus透镜设计出了10路功率合成器,对不同结构的功率合成器和不同参数的透镜进行了研究,得到了最终的优化结果.CST-MMW的仿真结果表明该功率合成器在30 GHz合成效率可以达到92.6%,并且其80%以上效率工作带宽可以覆盖整个Ka波段.     

基于二维Meniscus透镜的准光功率合成器(英文)

为了实现大功率容量和高效率的空间功率合成,将基于波导腔体的二维Meniscus透镜用于毫米波功率合成器的设计.对透镜中传输的主模(TE10波)的散射效应进行了分析,并且设计了匹配层减小透镜结构带来的反射.在30GHz频率上利用Rexolite介质的Meniscus透镜设计出了10路功率合成器,对不同结构的功率合成器和不同参数的透镜进行了研究,得到了最终的优化结果.CST-MMW的仿真结果表明该功率合成器在30GHz合成效率可以达到92.6%,并且其80%以上效率工作带宽可以覆盖整个Ka波段.     

Analysis of metal grating polarizers for quasi-optical power combining applications

Reflection and transmission characteristics of thin metal strip grating polarizers on dielectric substrate for quasi-optical power combining applications are analyzed by spectral domain method. Based on the calculated results, simple equivalent circuit models and empirical formula for analyzing metal grating polarizers are presented. The agreement between these simple expressions and spectral domain method are within one percent.     

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。     

Reflectance Measurement of Lossy Metal Meshes in the Millimeter-Wave Range

The method of power reflectance measurement of small lossy metal meshes is suggested by evaluating the measured reflection coefficient in the vicinity of a resonance mode of quasi-optical resonator. The resonator is described by the equivalent circuit that includes coupling ohmic losses of the mesh. The multi-points reconstructing algorithm is suggested to restore power reflectance. This particular technique is suitable for reflectance measurements of lossy metal meshes and wire grids having overall small dimensions which are not relevant when employing standard free space techniques. Its validity is illustrated by reflectance measurements in W-band.     

Two millimeter solid-state source global optimum for quasi-optics power combiner

A global optimization method for discussing quasi-optical power combiner of solid-state millimeter-wave source is provided. The device we use operate at about 150 GHz and GaAs Gunn diodes are chosen here as active sources arranged in a planar matrix of N×N (N-3,5,..., 2k+1, where h is positive integer). The best array and the location of the active elements in the source-array plane which is the surface of one reflector we will discribe later can be given by global optimization, where the radio frequency power can reach sixfold to ninefold larger than the total sum of the individual diode power.Work suported by natural science fund of China.     

Study on the high power air-coupled ultrasonic compound transducer

The high power air-coupled compound ultrasonic transducer in flexural vibration is studied. The transducer consists of a sandwich longitudinal piezoelectric transducer and a circular thin plate in flexural vibration. The resonance frequency equation and the equivalent circuit of a circular radiator with clamped boundary condition are derived. The resonance frequency equation and the equivalent circuit of the compound transducer are also obtained. The radiated acoustic field of the circular thin plate radiator is analyzed and the directional pattern is calculated. It can be seen that when the vibrational order of the circular thin plate in flexural vibration is increased, the radiated acoustic field becomes complex.