Improved procedure for measuring efficiency of small antennas in reverberation chambers

We show that the accuracy of measuring the efficiency of an antenna in a reverberation chamber can be improved if the calibration antenna is located inside the chamber during the test measurements and visa versa, and they must together represent the same load in the chamber during both calibration and test measurements. The error by not doing so depends on the total loading of the chamber. In our case, with a cylinder, the systematic error is about 0.2 dB at 1800 MHz.