We introduce an asymmetrical mirror design to a 140 GHz TE_（22,6） quasi-optical（QO） mode converter system to correct the asymmetry of the beam＇s field distribution caused by the Denisov launcher. By such optimiza...We introduce an asymmetrical mirror design to a 140 GHz TE_（22,6） quasi-optical（QO） mode converter system to correct the asymmetry of the beam＇s field distribution caused by the Denisov launcher. By such optimization, the output beam with better symmetrical distribution is obtained at the system＇s output window. Based on the calculated results,the QO mode converter system＇s performance is already satisfying without iterative phase correction. Scalar and vector correlation coefficients between the output beam and the fundamental Gaussian beam are respectively 98.4% and 93.0%,while the total power transmission efficiency of the converter system is 94.4%. The assistance of optical ray tracing to the design of such QO mode converters is introduced and discussed as well.展开更多
An improved method for analyzing the radiation characteristic of the quasi-optical launcher is presented. The launcher is decomposed into an open-ended waveguide and a helical cut according to the proposed method. The...An improved method for analyzing the radiation characteristic of the quasi-optical launcher is presented. The launcher is decomposed into an open-ended waveguide and a helical cut according to the proposed method. The radiation from the open-ended waveguide is obtained by using the Stratton-Chu formulation. The helical cut＇s radiation is calculated based on its current distribution, gained by several iterative computations, which helps to improve the calculation accuracy since the diffraction effect introduced by the helical cut is considered during the calculation. The proposed method is used to study different launches, and the results are compared with the existing results. Good agreement is achieved between the results obtained from our proposed method and the reported results. The present results provide an alternative for analysis and synthesis of the optical-mode converter.展开更多
We report the design of three frequency selective surface （FSS） filters used on the FengYun-4 （FY-4） microwave satellite, which separate five-frequency bands in the frequency range of 50-429 GHz with the insertion...We report the design of three frequency selective surface （FSS） filters used on the FengYun-4 （FY-4） microwave satellite, which separate five-frequency bands in the frequency range of 50-429 GHz with the insertion loss less than 0.4 dB, and separation between adjacent channels more than 20 dB for either TE or TM incidence. Firstly, we briefly introduce the disadvantages of two types of FSS filter： waveguide-array FSS and printed FSS, which are commonly employed in the millimeter and sub-millimeter wave band. In order to meet the insertion loss requirement and specified spectral transmission response, we adopt a filter composed of two closely spaced freestanding metal plates, which con- tains an array of resonant ring slot elements. Computer simulation technology （CST） is used to optimize the structural dimensions of the resonant unit and interlayer separation. Numerical results show that these FSS filters exhibit trans- mission loss of less than 0.4 dB and separation between adjacent channels of more than 20 dB. Simulated transmission coefficients are in close agreement with the required specification, and even exceed the performance specifications.展开更多
A quasi-optical dielectric lens used for W-band focal plane array passive imaging has been developed. The imaging system requires the lens to form beam spot with 3 dB width less than 35 mm at distance of 3500 mm. The ...A quasi-optical dielectric lens used for W-band focal plane array passive imaging has been developed. The imaging system requires the lens to form beam spot with 3 dB width less than 35 mm at distance of 3500 mm. The powerful optical design software ZEMAX was utilized to design the contours of the lens, and numerical method based on ray tracing and Huygens’ Principle was processed to verify the design result. Measurement result shows that the 3 dB width of the beam spot formed by the lens is 34 mm at distance of 3460 mm, and the beam pattern on imaging plane are equally arranged and the intensity decreases only 0.55 dB while the object lateral deviation increases to 300 mm.展开更多
A novel quasi-opitcal resonance system modified axisymmetrical quasi-optical cavity of oblique ratation(MAQCOR)-is proposed using the laplace integral transormation the kinetic theory of the high relativsitic electron...A novel quasi-opitcal resonance system modified axisymmetrical quasi-optical cavity of oblique ratation(MAQCOR)-is proposed using the laplace integral transormation the kinetic theory of the high relativsitic electron cyclotron maser with MAQCORis carried out within the framowrk of the linearized vlasov-mxawel eauations the formulas of beamwave intreaction power starting current and frequency shift have been derived some important plroblems such as high-order harmonic modes competition inflneces of the rationg angle and space charge and space chrage effcet are andlyaed and discussed in detall and a serios fo new condinsions are obtained a theoretical bssia is laid for the design of this novel qussi-optical gyrotron展开更多
The electromagnetic field integral equation in the quasi-optical cavity is obtained using the dyadic Green’s function. An expression is derived for the input impedance of a single microstrip patch cavity excited by a...The electromagnetic field integral equation in the quasi-optical cavity is obtained using the dyadic Green’s function. An expression is derived for the input impedance of a single microstrip patch cavity excited by a coaxial probe using moment method. The input impedance of a rectangular microstrip patch is discussed with this method. The result of this paper is similar to that of the microstrip antenna. This paper is of very important value for designing microstrip quasi-optical oscillator.展开更多
基于准光技术在亚毫米波频段设计分析了一种单脉冲天线。采用时域有限差分(FDTD)方法结合斯特拉顿-朱兰成(Stratton-Chu)公式对该准光单脉冲天线的辐射性能进行了严格的仿真分析。为了进一步抑制辐射和波束方向图的副瓣电平,引入了修正...基于准光技术在亚毫米波频段设计分析了一种单脉冲天线。采用时域有限差分(FDTD)方法结合斯特拉顿-朱兰成(Stratton-Chu)公式对该准光单脉冲天线的辐射性能进行了严格的仿真分析。为了进一步抑制辐射和波束方向图的副瓣电平,引入了修正的介质双曲透镜。仿真结果表明,该单脉冲介质透镜天线具有良好的辐射特性,其中和波束的副瓣电平小于-11.9 d B,差波束的零深低于-30.0 d B,不平衡度小于0.50 d B。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61671032)
文摘We introduce an asymmetrical mirror design to a 140 GHz TE_（22,6） quasi-optical（QO） mode converter system to correct the asymmetry of the beam＇s field distribution caused by the Denisov launcher. By such optimization, the output beam with better symmetrical distribution is obtained at the system＇s output window. Based on the calculated results,the QO mode converter system＇s performance is already satisfying without iterative phase correction. Scalar and vector correlation coefficients between the output beam and the fundamental Gaussian beam are respectively 98.4% and 93.0%,while the total power transmission efficiency of the converter system is 94.4%. The assistance of optical ray tracing to the design of such QO mode converters is introduced and discussed as well.
文摘An improved method for analyzing the radiation characteristic of the quasi-optical launcher is presented. The launcher is decomposed into an open-ended waveguide and a helical cut according to the proposed method. The radiation from the open-ended waveguide is obtained by using the Stratton-Chu formulation. The helical cut＇s radiation is calculated based on its current distribution, gained by several iterative computations, which helps to improve the calculation accuracy since the diffraction effect introduced by the helical cut is considered during the calculation. The proposed method is used to study different launches, and the results are compared with the existing results. Good agreement is achieved between the results obtained from our proposed method and the reported results. The present results provide an alternative for analysis and synthesis of the optical-mode converter.
文摘We report the design of three frequency selective surface （FSS） filters used on the FengYun-4 （FY-4） microwave satellite, which separate five-frequency bands in the frequency range of 50-429 GHz with the insertion loss less than 0.4 dB, and separation between adjacent channels more than 20 dB for either TE or TM incidence. Firstly, we briefly introduce the disadvantages of two types of FSS filter： waveguide-array FSS and printed FSS, which are commonly employed in the millimeter and sub-millimeter wave band. In order to meet the insertion loss requirement and specified spectral transmission response, we adopt a filter composed of two closely spaced freestanding metal plates, which con- tains an array of resonant ring slot elements. Computer simulation technology （CST） is used to optimize the structural dimensions of the resonant unit and interlayer separation. Numerical results show that these FSS filters exhibit trans- mission loss of less than 0.4 dB and separation between adjacent channels of more than 20 dB. Simulated transmission coefficients are in close agreement with the required specification, and even exceed the performance specifications.
文摘A quasi-optical dielectric lens used for W-band focal plane array passive imaging has been developed. The imaging system requires the lens to form beam spot with 3 dB width less than 35 mm at distance of 3500 mm. The powerful optical design software ZEMAX was utilized to design the contours of the lens, and numerical method based on ray tracing and Huygens’ Principle was processed to verify the design result. Measurement result shows that the 3 dB width of the beam spot formed by the lens is 34 mm at distance of 3460 mm, and the beam pattern on imaging plane are equally arranged and the intensity decreases only 0.55 dB while the object lateral deviation increases to 300 mm.
基金the National Natural Science Foundation of China the Doctoral Fund of Education Committee of China
文摘A novel quasi-opitcal resonance system modified axisymmetrical quasi-optical cavity of oblique ratation(MAQCOR)-is proposed using the laplace integral transormation the kinetic theory of the high relativsitic electron cyclotron maser with MAQCORis carried out within the framowrk of the linearized vlasov-mxawel eauations the formulas of beamwave intreaction power starting current and frequency shift have been derived some important plroblems such as high-order harmonic modes competition inflneces of the rationg angle and space charge and space chrage effcet are andlyaed and discussed in detall and a serios fo new condinsions are obtained a theoretical bssia is laid for the design of this novel qussi-optical gyrotron
基金Supported by the National Science Foundation of China
文摘The electromagnetic field integral equation in the quasi-optical cavity is obtained using the dyadic Green’s function. An expression is derived for the input impedance of a single microstrip patch cavity excited by a coaxial probe using moment method. The input impedance of a rectangular microstrip patch is discussed with this method. The result of this paper is similar to that of the microstrip antenna. This paper is of very important value for designing microstrip quasi-optical oscillator.
文摘基于准光技术在亚毫米波频段设计分析了一种单脉冲天线。采用时域有限差分(FDTD)方法结合斯特拉顿-朱兰成(Stratton-Chu)公式对该准光单脉冲天线的辐射性能进行了严格的仿真分析。为了进一步抑制辐射和波束方向图的副瓣电平,引入了修正的介质双曲透镜。仿真结果表明,该单脉冲介质透镜天线具有良好的辐射特性,其中和波束的副瓣电平小于-11.9 d B,差波束的零深低于-30.0 d B,不平衡度小于0.50 d B。
