Scalar Network Analyzer, The Design And Implementation Of Key Modules

In order to evaluate the performance of the system, scalar network analyzer can obtain the modulus of reflection and transmission coefficients by measuring the frequency response characteristics of the linear network. It is composed mainly by the sweep signal source, the scalar voltmeter and S-parameter measurement device. Scalar network analyzer is not only practical in wireless radio frequency (RF) component measurement and the measurement of device linearity can also be applied to the measurement of materials and signal integrity. In this context, this project designed a scalar network analyzer for RF network parameter measurement which of the frequency range is2GHz to3GHz and its output power range from+10dBm to-20dBm.In this paper, the scalar network analyzer with transfer/reflection structure presents the detailed performance index parameters in order to design and selection of devices. Frequency synthesizer chip ADF4350is for the development of microwave frequency sweep signal source to provide incident signal. Through the low noise amplifier for power amplification, voltage-controlled attenuator controls the whole gain. Signal conditioning circuit module uses microstrip equalizer and band-pass filter to improve the flatness of the signal and filter out the clutter. Ultimately extract the transmitted signal and reflected signal of the DUT by the detector module to the calculation of the parameters. Man-machine interaction module of the system is comprised of touch screen and DSP controller. It can display interactive user interface and monitoring functions of each module.During the entire system design process, I have given full consideration to a variety of issues. The scalar network analyzer is not designed only to achieve the basic functionality, but also can measure the absolute power of the response signal, and can be used as a signal source. It is relatively low cost and small size. The proposed intelligent power solutions to reduce power consumption, can be assembled into a portable instrument to facilitate the marketing and promotion of the analyzer.