Troubleshooting setup with simple coaxial antenna for TDMA-GSM EMI/EMC in audio systems

Mobile phones using Time Division Multiple Access (TDMA) technology generate audio noise on audio systems using speakers, specially if long cables are used. In general, any RF amplitude modulated signal can interfere other electronic systems when entering the circuits and being rectified (“audio rectification”). In this paper a simple setup for troubleshooting a system for that audio rectification problem is described. An RF power amplifier and a coaxial antenna are described as key elements of the setup and the general ideas about the use of the system are included.