Bluetooth Measurements in a Reverberation Chamber
Radios that comply with the Bluetooth wireless specification operate in the unlicensed, 2.4 GHz radio spectrum ensuring communication compatibility worldwide. These radios use a spread spectrum, frequency hopping, full duplex signal at up to 1600 hops/sec. The signal hops among 79 frequencies at 1 MHz intervals to give a high degree of interference immunity. Up to seven simultaneous connections can be established and maintained.
The radiated power of Bluetooth units can be measured in a reverberation chamber.
The reverberation chamber supports a uniform field environment, i.e. all incident angles is represented in the chamber.
Possible to easily include objects, such as a head phantom or a metallic table, in the setup to simulate the influence on the performance of the unit.
The present setup can be used without the need for a radio communication tester.
An example of a test case is shown below, where a commercial Bluetooth dongle is tested in free space and a position corresponding to normal use.
Bluetest RC800 reverberation chamber and setup for Bluetooth measurements. The field is stirred by 2 mechanical stirrers, a platform stirrer, polarization stirring and 25 MHz frequency stirring.
Module in test position (in the case and connected to a laptop, standing on a simulated wooden table)
Test module in free space (removed from case and placed on styrofoam)
Output power of a commercial Bluetooth module in free space location and inside a case mounted to a laptop computer, both measured in a reverberation chamber.
