Radio frequency (RF) and microwave applications involve transmitting and receiving electromagnetic signals at high frequencies. While these terms are often used interchangeably, RF means AC signals at 3 kHz to 300 GHz. For microwave, it’s more like 300 MHz to 300 GHz. Capacitors play a central role in these applications because they are concerned with capacitance, naturally, and impedance (i.e., resistance), which vary with frequency. Functionally, these passive electronic components store energy in an electric field.
With many options for configurations and applications, capacitors support a variety of functions in RF and microwave circuits. Here are some examples of key roles they play in these applications.