01-14-2022, 11:00 AM
The interfering noise disappears when I touch the bottom printed antenna just above the microphone hole (with the phone facing down). It is enough to firmly touch it with a finger or a short wire or loop.
But that seems to negatively affects the antenna's performances as reported by AT+CSQ command. That returns the received signal strength. Without touching the antenna, I get a value of 14, which is reduced to 10 when touching -- which means the received signal is weaker.
Since the transmitting signal is the one interfering with the mic, I'll search for a way to make it weaker from the modem, instead of messing the antenna...
But that seems to negatively affects the antenna's performances as reported by AT+CSQ command. That returns the received signal strength. Without touching the antenna, I get a value of 14, which is reduced to 10 when touching -- which means the received signal is weaker.
Since the transmitting signal is the one interfering with the mic, I'll search for a way to make it weaker from the modem, instead of messing the antenna...