3D printing is used to produce a wide variety of electronic components. 3D printing is cheaper and faster than traditional subtractive manufacturing. This makes it especially suited for prototyping printed circuit boards, capacitors, and sensors.
Rather than take days or even weeks, components like circuit boards can be built, tested, and iterated in hours at a much cheaper cost. 3D printing is being used for more than just prototyping electronics, however.
Various end-use components like antennae and radio frequency parts used in communication devices are being 3D printed. Harrison Corporation, a company that specializes in communications equipment, has a 3D-printed RF amplifier that performs on par with a traditionally manufactured amplifier. Source