Радіоелектронні і комп'ютерні системи (Sep 2023)
Active-passive pulse noise radar of the 3mm range and the results of preliminary tests
Abstract
The subject of this manuscript is broadband noise signals and systems. The aim of this research is to show the results of a modern active-passive 3-mm waveband system consisting of a noise-pulsed radar and a radiometer. Noise radar systems (NRS) based on broadband signals are characterized by high resolution, accuracy, and information content when performing unambiguous measurements of the range and speed of targets, as well as increased electromagnetic compatibility and noise immunity. These distinctive features of NRS determine the relevance of their construction for practical tasks of short- and medium-range radar. Additional opportunities for ensuring secrecy, reliability of detection of objects, and their tracking are provided by the combination of active and passive location modes in conjunction with advancement to the short-wave part of the millimeter (MM) wave band (WB). The most important characteristic of any pulsed radar, which largely determines its potential for practical application, is the operating frequency, as well as the shape and width of the probing signal spectrum. The main idea of this work is to describe the construction scheme and the results of preliminary tests of the developed active-passive system in the 94 GHz band with a noisy 20–100 ns illumination pulse in the 5 GHz band. The obtained values of the energy potential of the system in the active location mode (-105 dB) and the achieved radiometer sensitivities in the passive mode (0.007K and 0.03K) make it possible to observe ground and air objects at a distance of several kilometres. Noted that the measured parameters of the radar, in the case of processing the received signal by pulse compression methods, make it possible to count on ensuring the resolution of targets in range at the level of 10-15 cm. A multiple (more than an order of magnitude) decrease in the interference fluctuations of the received signal, which is due to the facet nature of the backscattering of targets, has experimentally demonstrated using a noise probing pulse compared to a single-frequency pulse. The methods for further work on the development and practical application of the constructed measuring system are outlined.
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