Vector Network Analyzer System Software Design

This thesis describes in detail the design and implementation of the system software in vector network analyzer(VNA), which mainly consists of the requirement analysis of the system software, the software structure analysis and detailed design, the key techniques utilized in the software design, the S-parameter algorithm as the core technique in VNA, and software testing.The paper conducts a thorough research of the method and principles in VNA measurement, and performs detailed requirement analysis of system software relying on the hardware architecture. Based on the requirement analysis, a detailed layered design is put forward, which partitioned the system software as three parts: user interface, data processing, hardware interface along with PCI communication.The user interface is developed with CVI embedded in the Visual C++ develop environment, including menu, soft keyboard, view area, measurement information configuration area and measurement information display area. The data processing part includes FFT, filter and averaging, calibration algorithm, Smith Chart designing, S-parameter algorithm, transmission and reflection caculating, etc. The hardware interface consists of control information protocol, data transfer protocol, status information protocol and the synchronization protocol of the transfer of all the above information. The data structure partitioning in the software design largely utilizes structural design and modularized implementation.The system software testing suite is designed in the last chapter, including the structural test, function test and performance test. Due to the incompletion of the hardware part, the system software simulation of the VNA's measurement process verifies the stability of the system software and the feasibility of the software design.