Capacitors For Rf Applications

28 CAPACITORS FOR RF APPLICATIONS A brief overview of currently available devices in an electronic component group whose significance for telecommunications and radio circuits is often grossly underestimated. Today"s electronic component market of- fers a vast range of capacitors for use in high-frequency circuits. Many design en- gineers and home constructors are, there- fore, often faced with a real dilemma when it comes to choosing and mounting the right capacitor in the right place. In many cases, parts lists of construction pro- jects will provide the value of the capaci- tor, but references like "PTFE foil trimmer", "coffin-type leadless ceramic", "ceramic NPO", "tubular", and many more, may not be familiar. Ceramic capacitors These small devices are probably the best known types for use in RF circuits because they are cheap and have been with us for many years. The lead spacing is usually 2.5 or 5 mm for the modern disc and plate types, of which some have rims below the cap...