The Research Of Low Cost And High Precision S Parameter Measurement System

With the widely application of the wireless communication, the demand of RFcomponents especially various kinds of antenna are increasing. Parameters consistency ofRF components has caused concern in the industry. Network analyzer is the importantequipment to measure the RF parameters; but its high price increases the cost of production.So design and development of the low cost and high precision S parameter measurementsystem has very important realistic significance.A set of S parameter automatic measurement system that it is suitable for productionline is built in this paper. The S parameter measurement system consists of hardware andsoftware. The hardware contains signal generator, RF-SPDT switch matrix, power meter,directional coupler and PC. The software consists of PC communication with signalgenerator, power meter and switch matrix and control them, as well as deal with the data.The design of directional coupler, communication between the equipments, and calibrationtechnology for measurement parameters are the important points in this paper.The thesis is divided into five parts. The first part is introduces the principle of thenetwork analyzer to measure S parameters, and discusses the possibility of using otherinstrument instead of network analyzer to measure the S parameter. The second part isdiscusses the design of system architecture including equipment selection, systemconnection and in the coming work, All these are based on the principle of the insertionloss and return loss test. The third part is discusses the main performance of the directionalcoupler, and proposes a new direction coupler structure. I simulate it using HFSS, andmake a sample. The test report shows that the directional coupler can meet the requirements of the measurement system. The fourth part is introduces the process ofdesigning the software. Firstly, introduces the software interface and operation method,and its main function used. Then, discusses the design of software communication withsignal generator, switch matrix and power meter devices. Lastly, introduces the design ofthe data post-processing software. The fifth part discusses the realization of the system,including the system debugging and verification, the error analysis and calibration. Theresult shows that using this measurement system can easily measure two-port networkinsertion loss and return loss of stand-up networks. This system has the features of low cost,automation, friendly interface, good scalability and so on. It provides a new way for theconsistency test of the microwave components performance in the production line.