There are several methods for making noise figure (NF) measurements of RF, microwave, and millimeter-wave low noise amplifiers (LNAs), each with a wide number of options, instruments, and techniques. In a recent Tech Brief, Erzia reviews how we came up with an approach using standard laboratory equipment that can easily be followed by trained personnel working at higher frequencies to obtain optimal NF data.
The traditional approach to delivering hardware to be installed in satellites and space probes is driven by extensive design, analysis, and testing phases, with long-term delivery times and budgets, which can be tens or hundreds of times bigger than their equivalent for commercial and terrestrial applications. These extensive deliveries and larger budgets are justified by the expectation of the hardware to survive and operate in the extremes of the space environment, without any possibility of reparation or replacement.
Spectrometers employing acousto-optic tunable filters (AOTFs) are rapidly gaining popularity in space, and in particular on interplanetary missions. According to a paper published by the National Center for Biotechnology Information, “they allow for reducing volume, mass, and complexity of the instrumentation and are used for analyzing ocean color, greenhouse gases, atmospheres of Mars and Venus, and for lunar mineralogy. The AOTFs are used in point (pencil-beam) spectrometers for selecting echelle diffraction orders, or in hyper-spectral imagers and microscopes.”