In this configuration, a calibrated noise tube is used as a standard noise source to calibrate the system over the entire V-band before the actual noise measurement of the IMPATT source can begin.
This prototype is self contained and does not need an external power supply to generate noise at V-band, in contrast to a noise tube that requires a bulky and relatively expensive power supply to provide the high voltages necessary to start the gas discharge process.
The purpose of these investigations was to propose workable and stable IMPATT-loaded waveguide cavities at V-band to replace the existing high cost, relatively cumbersome gas discharge noise tubes.
As a result of these investigations, noise tubes to a large degree may be replaced by IMPATT-loaded RH-RH waveguide cavity mounts, with good stability of operation in time and temperature.
The current noise tube consists of an argon-filled glass tube that is positioned at an approximate angle of 10 [degrees] to the broad face of the waveguide.
Actually, such a solid-state noise source is expected to have several advantages over conventional noise sources, such as temperature-limited thermionic diodes or a gas discharge noise tube.
In this configuration, a calibrated noise tube is used as a standard noise source to calibrate the system before the actual noise measurement of the IMPATT source can begin.
Such a solid-state noise source has shown to be superior to the state-of-the-art noise sources, such as a gas discharge noise tube.
Nevertheless, no substantial work or result leading to the actual production of noise sources in lieu of gas discharge noise tubes in mm-wave regions has been reported.