Most of today’s digital-based products create a large amount of on-board RF harmonic “noise” (EMI). While this digital switching won’t usually bother the digital circuitry itself, that same harmonic energy from digital clocks, high-speed data buses, and especially on-board DC-DC switch-mode power supplies can easily create harmonic interference well into the 600 to 850 MHz cellular phone bands and even as high as 1575 MHz GPS/GNSS bands, causing receiver “desense” (reduced receiver sensitivity).
An increasing number of manufacturers are adding or retrofitting wireless technology into new or existing products. These products typically include mobile, household, industrial, scientific, and medical (ISM) devices. This transition towards “everything wireless” is in full swing, and with it comes problems with electromagnetic interference (EMI) from the product itself interfering with sensitive on-board cellular, GPS/GNSS, and Wi-Fi/Bluetooth receivers. Read on to find out what to do about it.