Novel attenuation standards at microwave frequencies and evaluation of their uncertainty

Abstract

We have developed two coaxial-type microwave attenuation standards using the power ratio transfer method. One standard operates in the frequency range of 18 GHz to 26.5 GHz, and has a dynamic range of 80 dB. Its expanded uncertainty (k = 2) is estimated to be 0.01 dB/80 dB. The other operates in the frequency range of 26.5 GHz to 40 GHz, and has a dynamic range of 60 dB and an expanded uncertainty of 0.009 dB/60 dB. We present an example for calibration of a 40 dB step attenuator using the attenuation standard in a series radio-frequency substitution scheme. The expanded uncertainty (k = 2) is 0.01 dB including the mismatch uncertainty.

Determining noise temperature of a noise source using calibrated noise sources and an RF attenuator

“…1 is used to connect the DUT to a receiver with a coaxial input port. Naturally, the adapter has to be characterized using an appropriate evaluation technique [9]. In this paper, the one-port RT technique was used.…”

“…Fig. 3 illustrates magnitudes of S 21 of the 10-dB coaxial attenuator measured by a VNA and by the attenuation standard system [9]. Measured reflection coefficient S 11 of the attenuator ranges from −33 to −23 dB.…”