scope:

Is applicable to intermodulation products in waveguides. The objective of the test procedure given below is to characterise the level of unwanted signals caused by the presence of two or more transmitting signals in waveguides or waveguide assemblies. The basic theory of the generation of intermodulation products in RF circuits is well described in the literature. In the case of passive waveguide components, intermodulation disortion is caused by sources of non-linearity of mostly unknown nature, location and behaviour. A few examples are: intermetallic contacts, corrosion products, dirt, etc. Most of these non-linearities generate measurable intermodulation products only when exposed to relatively high RF-power levels (>1 W). Threshold and cut-off effects are found frequently, In addition, most of these effects are subject to changes over time due to mechanical stress, temperature changes, variations in material characteristics (cold flow, ets), climatic changes and so on.