Communications Technology Handbook, 2nd Edition

20 Microwave devices

The microwave wavelengths range from 1 metre down to 1 centimetre, corresponding to a range of frequencies from 300 MHz to 30 GHz. Above 30 GHz the phenomenon is referred to as the millimetre wave range which at present, apart from optical techniques, is little used for communications purposes. For components and devices, the range between about 300 MHz and 1 GHz forms something of a transition region. The shorter wavelengths, together with lower periodic and transit times, plus component self-capacitance and lead inductance, all act to increase the losses in components of the conventional construction that are used for the bulk of communications at lower frequencies. For this reason, devices that are intended for use above ...