Hi, I would like to implement RF attenuation mechanism for electronic device using BLE (2.4 GHz) controller. For that purpose, I used programmable EVAL-ADRF5700 board with digital control inputs. When I test wired setup, where BLE antenna port is connected directly to the spectrum analyzer, I got all attenuation levels as expected (starting from 2dB up to max 46dB). However, when there is standard PCB or whip BLE antenna in place (without spectrum analyzer) and wireless link established with counterpart device, RF attenuation cannot go beyond 25-30dB. I need to inject more (ideally 46dB) and simulate weak BLE signal that may lead to disconnection. The overall attenuation effect in wireless setup is observed using RSSI values (Nordic, ESP32 and other sniffer controllers).

Do you have any recommendation how to implement 46dB attenuation in wireless setup? What is expected behavior in office environment?

PS: I do not have any anechoic chamber for now. Instead, our test setup is installed in office with different PCs, BLE devices (mouse, keyboard dongles etc.) that may interfere signal strength.