The waveguide below-cutoff attenuation standard

Abstract

A semitutorial review of the history, development, and application of waveguide below-cutoff (WBCO) attenuation standards is presented. A brief summary of the electromagnetic (EM) theory is followed by descriptions of the various designs implemented over a span of 60 years. Designs range from simplistic to elaborate electromechanical creations that stretch the toolmaker's art yet are ultimately dependent upon the primary standard of length.Index Terms-Attenuators, calibration, high frequency, measurements, standards, uncertainty, waveguide standards. David H. Russell is a microwave/millimeter wave engineer who retired from the Electromagnetic Fields Division, National Institute of Standards and Technology (NIST), Boulder, CO, in 1993. As a Group Leader, he directed the development of power, noise, impedance, and attenuation standards, and their application in automated measurement systems. His group also did pioneering work in design and fabrication of on-chip standards for monolithic microwave integrated circuits (MMIC) device metrology. During 38 years at NIST, his research interests were primarily in standards and systems for microwave and millimeter wave attenuation metrology in coaxial, uniconductor, and planar waveguides.

Novel attenuation standards at microwave frequencies and evaluation of their uncertainty

“…In RF and microwave attenuation measurement, waveguide below cutoff (WBCO) attenuators and inductive voltage dividers (IVD) have been used as a reference system for attenuation measurements. The WBCO and IVD operate at the particular frequencies of 1.25/30 MHz and 1 kHz, respectively [1]. For attenuation measurement at other frequencies, mixers are used to convert the RF or microwave signal that passes through the device under test to the frequency at which the reference attenuator is used [2].…”