NPL Mk 3 WBCO Attenuator

A waveguide below cutoff attenuator has been developed which has the following features: 1) high accuracy and resolution, 2) frequency coverage from 10 MHz to 1 GHz at discrete frequencies, 3) readout direct in dB, 4) compatibility with automatic attenuation measurement systems. Although this instrument is of standard laboratory caliber, the design is simple and the unit is inexpensive to produce, requiring high mechanical accuracy only for the precision waveguide section and the associated piston.