A Vector Network Analyzer Based on Pulse Generators

摘要

A fast four channel network analyzer is introduced to measureS-parameters in a frequency range from 10MHz to 3GHz.The signal generation for this kind of analyzer is based on pulsegenerators, which are realized with bipolar transistors. Theoutput signal of the transistor is differentiated and two shortpulses, a slow and a fast one, with opposite polarities aregenerated. The slow pulse is suppressed with a clipping network.Thus the generation of very short electrical pulses with aduration of about 100ps is possible. The structure of thefollowing network analyzer is similar to the structure of aconventional four channel network analyzer. style="line-height: 20px;">All four pulses, which contain the high frequency information ofthe device under test, are evaluated after the digitalization ofintermediate frequencies. These intermediate frequencies aregenerated with sampling mixers. The recorded data is evaluatedwith a special analysis technique, which is based on a Fouriertransformation. style="line-height: 20px;">The calibration techniques used are the same as for conventionalfour channel network analyzers, no new calibration techniques needto be developed.