| Abstract :
Contrary to popular belief passive components such as capacitors, inductors and
even interconnects can cause distortion of signals. This is even more becoming true
with the minaturisation of components. Generally this distortion is dependent on choice
of materials and geometry of the components and their contacts. In many cases the
distortion is bias dependent. If it all, only minimal information is available to the
designer. Manufacturers generally don't specify distortion figures and literarature is
many times subjective and misleading, especially in the audio world.
The aim of this work is to set up an easy to use and performent measurement
system and to analyse and categorize components and causes.
And ultra low distortion signal generator (1KHz) is built with selected
components. This 1 KHz signal is send through the DUT and then attenuated with a Tee
notch filter (-65dB). The spectrum then is further amplified and FFT analysed on PC for
distortion.DC biasing of the DUT is also possible. Distortion can instantly be analysed
and interpreated from the obtained measurements. With this measurement set up, the
designer has an easy to use tool to measure and compare components of his design.
Values of distortion have been found that are important in critical design such as
instrumental amplifiers, low phase noise circuits, confirming previous
findings.Harmonic distortion sometimes can be lowered by tens of dB's by using a
proper selected capacitor.
Several components , built in different technologies will be measured and
selection criteria will be set up for these nominal linear components.