Non-linearities in metal contacts at microwave frequencies

Starting with a comprehensive literature survey, the work reported in the thesis consists of a mathematical analysis and then measurements of the 3rd- and 5th-order intermodulation products produced by the non-linearities of a large number of various metal contacts.
The experimental study concentrated on the intermodulation products generated at the contacting faces between similar and dissimilar metals and included contact materials of copper, beryllium copper, brass, oxygen free copper, oxygen free nickel, mild steel, stainless steel (EN58B), duraluminium and twelve home-made steels with various compositions.
The measurements were carried out for the first time at L-band frequencies on a good experimental arrangement.
The fundamental excitation frequencies were f1 = 1.3GHz and f2 = 1 7GHz and the 3rd- and 5th-order intermodulation products were 2f2 - f1 = 2.1GHz and 3f2 - 2fl = 2.5GHz respectively.
The quantitative studies were mainly concerned with the variation of the 3rd- and 5th-order intermodulation product levels with the power levels of the fundamental signals and with the axial force applied to the contact.