Abstract:The field distributions of the focal region, where the beam with a certain incident angle is focused by the spherical reflector, are theoretically calculated and measured. The results give evidence that the focusing system of the spherical reflector in grating spectrometer for millimeter waves (25~100GHz) strongly limits its resolving power. In- creasing the diffraction angles of the diffracted beam from a grating is an effective way to abate or eliminate this limit.

Abstract:The problems of analysis and design of the broadband groove guide directional couplers are investigated by the microwave network method. Using the transverse equiva- lent network for partially dielectric-filled asymmetrical double-groove guide, a related program for solving the problems is developed. The calculations show that the relative bandwidths of the couplers given in this paper are all larger than 24%, which is five times as many as the bandwidth of the conventionally designed groove guide couplers; whereas the lengths of the present couplers are much shorter than those designed in the references.

Abstract:A method for feature extraction and target recognition by using wide-band millimeter wave technology is presented. It is shown that radar targets can be described in terms of multiple scattering centers at the operating frequency of millimeter wave. With a modest bandwidth of the transmitted signals, features about spacial distribution, category and polarization of scattering centers can be extracted from the received signals. The meth- od is effective for high-frequency recognition of complex targets.

Abstract:A characteristic equation for calculating the propagation constants of modes in a circular waveguide, eccentrically loaded with a chiral rod is obtained through a coordination transformation based on the additions theorem for Bessel functions. As an example, calculated results for the dispersion characteristics of a circular waveguide eccentrically loaded with a chiral cylinder are presented. Variation of propagation constants with several parameters is discussed.

Abstract:分析研制了一种反射式腔稳双变容管调谐的毫米波耿氏振荡器,近(?)频相位噪声为-60dBc/Hz(f_m=1kHz);-95dBc/Hz(f_m=50kHz),粗(?)谐为10～20MHz/(0～15)V,细调谐为±1～±3MHz/(0～15)V,而且细(?)谐极性可变.并已成功地应用于毫米波系统中.

Abstract:The paper describes a W-band six-port reflectometer, including its design, calibration and error analysis. The waveguide junction is designed optimally by the use of the concept of generalized resonant cavity. The diode detectors are used as powermeters which are matched well. The equipment has been calibrated by many methods. For meas- uring two-port network parameters, a least square method is proposed, which has merits of easiness, quickness and high accuracy.

Abstract:A symmetrical five-port waveguide junction was developed. In the frequency band 26.5~40GHz, the junction yields a residual mismatch of less than 0.2 and a transmis- sion of 0.5.

Abstract:研制了一种由TPX介质双直角棱镜构成的可调功率分配器.用波长为337μm的HCN激光器作信号源,测得相对可调功率范围达14dB;用作可变衰减器时,可变衰减量达13.5dB,插入损耗约为4.5dB.

Abstract:Based on rigorous electromagnetic theory, an improved method suitable to ana- lyze Infrared and Millimeter wave Scattering of Two-dimensional Conductor-dielectric Periodic (2DCDP) Structures is presented in this paper. The effects of all electromagnetic parameters and geometry sizes, including those of the thickness and finite conductivity of conductors are taken into account and the numerical results can be obtained without in- voking any basis functions.

Abstract:The dispersive characteristics of microstrip lines involving ferrite media are stu- died in this paper by using the extended two-dimensional FD-TD method. The effects of the thickness of ferrite dielectric, the width of metal strip of microstrip and the applied DC magnetic field of ferrite media on the transmission characteristics are presented. The mode which can propagate more easily nearby the stopband of microstrip lines is also discussed.

Abstract:Mode coupling due to curvature in circumferentially corrugated circular waveguides is analyzed in this paper. Starting from Maxwell's equations in the annular orthogonal curvilinear coordinate-system, the integral formulae for coupling coefficients are derived. On the basis of them, the explicit expressions of coupling coefficients between positive or opposite modes are derived.