Noise can be disruptive, preventing a message from being heard. For effective use of wired and wireless communications systems, such as cellular “smart phones” and satellite communications (satcom) systems, noise should be minimized if possible. But first it must be detected and identified so that it can be treated, which requires test-and-measurement equipment for that purpose. Noise measurement equipment comes in a variety of forms, as many as the types of noise that plague modern communications systems.
Noise can originate from within or outside a system or component under test. Noise from a source outside the system can radiate through the air to a communications system and start within a noisy component, such as a switching power supply, a solar inverter, or the driver for a light-emitting diode (LED). Noise that is radiated travels through the air from a source to a receiver and is typically frequency dependent and diminishing in level with distance from the source. Noise can also