S – parameters are complex numbers. S – parameters are used extensively in the design of many high frequency functions such as amplifiers, mixers, oscillators etc. Some engineers prefer using them in rectangular format, while others prefer the polar format. In some ways the polar format is easier to deal with. This is the case when multiplying or dividing. The rectangular format is better ( or essential) when adding or subtracting). Although there appear to be one or two converters on the web, we were not too sure of their results so we designed a rectangular to polar converter in javascript ( a polar to rectangular one is in the works). Please visit our website and select the complementary items link to access the calculator.