We have developed a voltage-ratio based attenuation
measurement system from 50 MHz to 26.5 GHz at the National
Metrology Centre (NMC), Singapore [29–31]. In this
paper, the design of the our attenuation measurement system
is briefly described, and the noise floor of the proposed
measurement receiver is analysed. The DR of such a measurement
receiver is defined and it is shown that a very
wide DR has been achieved. At 26 GHz, the expanded measurement
uncertainty is estimated to be 0.012 dB for a
110 dB attenuator and 0.16 dB for a 150 dB attenuator,