Microwave Standing Wave Automatic Measurement System Design And Realization Of Teaching Experiment

For the exploration on the innovative teaching pattern of microwaveexperiments, a set of teaching experiment system for Standing microwaveautomatic measurement is designed and implemented, applying SCM technique,virtual instrument technique and computer interface technique.The system consists of Personal Computer, SCM control circuit, digitalmicro-DC galvanometer and stepper electromotor on the basic ofMicrowave Generator, microwave measurement line and attenuator. In theautomatic measuring, the computer gets users commands and runs thecorresponding automatic measurement program. The stepper electromotorcontrolled by SCM moves the probe in the measurement line, while in thegalvanometers the demodulation current is converted to voltage, amplified,and A/D conversed before the current data is sent to the computer fromCOM port. The user interface, programmed by LabVIEW language, drawsstanding wave graph after getting the current data and measures thewavelength in the wave-guide and the ratio of the standing wave.Main innovations in this paper:(1) A set of digital micro-DC galvanometer is designed andimplemented. Galvanometric output data can display by LCD or be sent tothe computer from COM port. It can be used in the teaching experiment,substituted for the expensive products in the market. It can communicatewith computer, thus is conductive to education modernization of teachingexperimental measurements.(2) Virtual instrument technique is firstly applied in the field of microwavemeasurement teaching experiments. It provides the intelligent measurement withmore obvious experiment phenomenon and less error then manualmeasurement. And, it provides the necessary user-computer dialogueoperation to prevent the ignorance of the principle and process. Thus, the teaching function and measurement function integrates in the system.