New Advances In Automatic Analysis Technique Of Microwave Networks And Its Applications

With the systematization and integration of military electron systems, the automatic analysis technique of microwave networks plays an increasingly important role in developing new weapons and equipments. According to the requirements for two national defense science & technology pre-research projects, some new advances in the automatic analysis technique of microwave networks are discussed in detail in this thesis. The main contributions of the author in this technique are outlined as follows:1). The response equations of the general three-port reflectometer are discussed and their united form is given. Some theorems on the three-port reflectometer are presented. Furthermore, a further analysis about the equivalent three-port reflectometer is performed and some useful conclusions are obtained. 2). A novel method for calibrating a reflectometer with scalar detection is described, which can be used to realize the electron calibration technique of the reflectometer with scalar detection. 3). A new multi-state reflectometer circuit is designed and realized in the laboratory and the reasonable measurement method of the scattering matrix is obtained. In addition, a single-state four-port reflectometer is presented and some new methods for measuring the source reflection coefficient and power meter calibration coefficient are also obtained by using the multi-state theory. 4). A dual-multi-state vector network analysis technique is presented for the first time in this thesis and its principle, calibration theory, practice circuit, and measurement method are discussed. Also, a novel method for calibrating a dual-multi-port vector network analyzer is achieved, which overcome the shortages of the available Thru-Line-Delay method. 5). A novel concept for vector measurement based on a scalar network analyzer and the multi-state theory is suggested. 6). A novel transmission/reflection method for noniterative stable determination of the complex permittivity is described by only one measurement in wide-band frequencies. Moreover, this method is successfully used to expand the frequency range of the traditional rectangular waveguide cell. 7). Two new nondestructive methods for measuring the material complex permittivity are acquired. One of these two methods is a numerical computing method and another is an equivalent circuit method. 8). A setup for measuring the electromagnetic parameters of linear materials based on multi-state techniques is developed and a method for the determination of electromagnetic parameters of materials is also presented by using the transformation coefficients of a two-port network. Finally, a novel method for the uncertainty analysis of measuring electromagnetic parameters is gained by employing flow chart of error transfer, which is valid for uncertainty analysis of a complicated test system.All of the above theoretical and experimental work is presented in the corresponding charters of this thesis.