RFnoise

RF noise refers to unwanted radio frequency signals that interfere with the intended transmission or reception of radio signals. It is a broad term covering both narrowband interference, such as a single-frequency emitter, and broadband disturbances that spread across a wide portion of the spectrum. Common sources of RF noise include electronic devices, power lines, switching power supplies, and natural phenomena such as lightning. In addition, human-made infrastructure such as broadcast transmitters and cellular base stations can contribute to the ambient noise floor.

The presence of RF noise can degrade the performance of communication systems by masking signals, causing bit errors, and reducing the effective signal-to-noise ratio. In military and aviation contexts, RF noise is a critical consideration because it can compromise navigation, surveillance, and secure communications. Engineers quantify RF noise using power spectral density measurements, expressed in watts per hertz or decibels relative to a reference level. Common test equipment for measuring RF noise includes spectrum analyzers, noise figure meters, and vector signal analyzers.

Mitigation strategies focus on both source reduction and signal design. Shielding, filtering, and proper grounding techniques reduce the generation and pickup of noise. On the receiver side, employing band-pass filtering, differential signaling, and error-correction coding helps to discriminate desired signals from noise. Compliance with international standards such as FCC Part 15 and IEC 61000-4-3 ensures that equipment operates within acceptable emission limits, thereby minimizing its contribution to the overall RF noise environment.