The Research Of Nonlinear Junction Detector Transmitter Module In S-band

Non-liner junction detector uses the principle of harmonic re-radiation characteristic to detect equipment which contains metal or semiconductors. The ability of clutter suppression and interference immunity makes the detector be widely used in security detection and other fields. With the rapid development of electronic technology, various types of electronic products and equipment emerge in endlessly, and the volume becomes smaller. So the market demands for the detection equipment with high-frequency, light weight and small size. Under this background, this thesis studies the transmit module of non-liner junction detector deeply.Based on the analysis and understanding of the existing non-liner junction detectors in the market, it can be known that L-band and S-band are widely used. Taking into account the advantage of S-band detector which can detect smaller targets, this thesis focuses on the design and realization of transmit module of non-liner junction detector, and uses design software such as ADS(Advanced Design System), HFSS(High Frequency Structure Simulator), Altium Designer, AutoCAD(Autodesk Computer Aided Design) to analysis and design devices and systems in detail.This thesis analyzes the application background of non-linear junction detector, and studies the principle and advantages of the detector. According to the indicators requirements, the program design, demonstration, and implementation of the transmit module of non-liner junction detector have been made. Specifically include that the theoretical analysis and selection of active devices, such as mixers, low-noise amplifiers, power amplifiers and others have been made, and various passive components of the system, such as low-pass filter, band pass filter, attenuator and power splitter have been designed, a few passive chips have been selected. The design and implementation of up-conversion link module and the two programs of adjustable power amplifier modules have been completed. The problems appeared in the module design process have been analyzed and summarized, and the modules have been tested.For the test results, this thesis analyzes the reasons of deviations, and provide the further improvement programs and ideas, which lay the foundation for the work carried out later.