1. Electromagnetic Interference:
Mobile phones use various radio frequencies for communication, including GSM, 4G/LTE, Wi-Fi, and Bluetooth. These frequencies are transmitted through antennas in the phone. When the phone is placed close to a radio, its electromagnetic signals can interfere with the radio's reception.
2. Modulation:
Mobile phone signals are modulated, which means that the information carried by the signal varies the frequency or amplitude of the signal. This modulation can cause the radio to pick up and amplify these variations, resulting in audible sounds.
3. Resonant Frequencies:
Radios are tuned to receive specific frequency bands. Certain components within a radio, such as the inductor or capacitor, can resonate at these frequencies, amplifying the interference caused by the mobile phone's signals.
4. Proximity to the Antenna:
The closer the mobile phone is to the radio's antenna, the stronger the interference will be. This is because the antenna is designed to receive electromagnetic signals, and the closer the source of the signal, the more energy it can capture.
To reduce or eliminate this interference, it is generally advisable to keep mobile phones away from radios or turn off the phone's wireless connectivity when not in use. Additionally, some radios may have built-in filters or shielding to mitigate the effects of electromagnetic interference.