Design And Realization Of Virtual And Actual Integration Mixer Circuit Remote Experiment Platform

In the cultivation of talents,the proportion of practical teaching is increasing.Experiment is not only a bridge between theory and practice,but also an important link in engineering teaching.However,the common problem in communication circuit teaching is the separation of theory teaching and practice teaching.It means after students finish their course and get in the laboratory,their experimental object is just experimental box,which can change only a few circuit components to observe the circuit performance changes.Therefore,it is an important task to construct a networked laboratory which combines the virtual simulation experiment with the traditional hardware experiment.The thesis constructed an integrated mixer circuit remote experiment platform based on NI Multisim circuit simulation software,graphical programming software Lab VIEW,and NI ELVIS.It makes close integration of circuit simulation design,hardware realization and circuit performance testing and analysis.The design and development of the remote experiment platform in this paper's main object is MC1496 analog multiplier mixer circuit and triode mixer circuit.Firstly,by using mixer theory and circuit design knowledge,the chip simulation model is established and the mixer circuit is designed and simulated by NI Multisim.It analyzes the DC operating point simulation,the Fourier simulation,the mixer gain and 1d B compression amplitude simulation,local oscillator signal amplitude analysis,frequency-selective network analysis,mixing interference and distortionanalysis and noise characteristics simulation analysis.The influence of different parameters of the circuit on the mixing characteristics is studied,and the optimal range of the parameter values is obtained.Secondly,according to optimized circuit,the hardware circuit PCB is designed including the design of two mixer circuit,hardware switch by relay and the communication interface with ELVIS.The PCB of the mixer circuit is manufactured and the soldering work is completed.Then using the virtual instrument on ELVIS platform to control and test the hardware circuit to verify the accuracy and effectiveness of the simulation results.Finally,a complete mixer circuit remote control experiment platform is developed by Lab VIEW programming.It is introduced the experimental analysis interface and program design and realized remote access by web publish technology.It can choose the experimental training content in the interface,including mixer introduction module,hardware parameter configuration module,simulation module and spectrum analyzer and oscilloscope module.It can be combined with Multisim and collect,measure,store and display the simulation data of Multisim,.By adjusting the input control parameters in the interface,dynamic display circuit performance changes,and achieve an automated simulation analysis experiment.At the same time,it can be combined with ELVIS platform.It integrates the ELVIS virtual instrument into the experiment platform that can realize the control and performance test of the prototype PCB circuit.A virtual and actual integration mixer circuit remote experiment platform is built.The test results show that the remote experimental platform is stable and easy to use,which can effectively relieve the contradiction between the large number of students and the lack of existing laboratory equipment,break through the time and space constraints,and provide students experimental circuit analysis and testing training anytime and anywhere,which has a certain practical value for laying the foundation to realize the cross from validation experiments to design experiments.