KRETs update regarding electronics. http://www.promweekly.ru/archive/kret/2021/KRET_1-2021.pdf
"high-frequency (microwave) tubes and analog waveguide components with solid-state microwave equivalents: low-noise emitters
low-power amplifiers, phase shifters,
complete PPMs made by technology
Monolithic microwave semiconductor integrated circuits (MMIC - Monolithic
Microwave Integrated Circuit).
As technology improves
in the last decade and a half, constantly
improved characteristics of PPM based on monolithic integrated circuits of the microwave range and
their cost decreased. When used in
gallium arsenide, then gallium nitride MMIC technology, the power output per module increased exponentially in normal ranges
Radar. The continuous exponential growth of the performance of individual circuits is expected to continue as they improve.
materials technology.
MULTIFUNCTIONAL
SYSTEMS
Another important trend in the development of modern radar technology is the creation of multifunctional systems operating on the same platform, possibly through one
and the same physical aperture. On ships or
airplanes, it can be a combination of radars for various purposes (observation, detection,
tracking, target illumination), communication lines in various frequency ranges and broadband
electronic warfare systems.
This allows you to reduce the size of stationary equipment on the carrier, increase
the ability to control and monitor the electromagnetic fields of antennas and reduce the cost
radar equipment. However
certain difficulties with this approach
may be related to EMC problems.
RADAR
SYSTEMS WITH SYNTHESIZED
APERTURE
Synthetic aperture radars, widely used to create
high-resolution 3D images, appeared four decades ago as
a productive solution to the problem of restrictions,
related to the aperture interface.
Diffraction analysis shows that for
obtaining permission from a radar station operating in
L-band (wavelength 30 cm) at a distance
several kilometers, the physical dimensions of the antenna should be approximately equal to the range,
that is, several kilometers.
The solution is to use the linear nature of Maxwell's equations for
creation of a synthetic aperture of the phased array by using a series of time samples,
received on a small consistent
movable antenna in those spatial
points at which one would need to have real
PAR elements in a physical antenna. Data
samples are collected and jointly processed to obtain the desired three-dimensional
high resolution images.
The growth of digital computational processing capabilities expands the areas of practical application of the synthetic aperture radar concept.
DIGITAL
RADAR SYSTEMS
According to American experts,
future generations of radars will not be based
only on solid-state phased array, but almost entirely on digital technology. As
used analog devices will remain
terminal input stages for coupling the antenna to the external environment for receiving analog
Microwave signals.
The received signals will be digitized and transmitted
on broadband fiber optic
communication lines for appropriate funds
processing remotely located outside
apertures for digital formation of the beam pattern,
in-phase and quadrature generation, compression
impulses, suppression of interfering echoes, target allocation, multivariate tracking.
Likewise, in transmit mode, digitally generated waveforms will be
generated outside the aperture and distributed over fiber optic lines at
separate elements of the antenna, where it will be emit digital-to-analog conversion
and power amplification on the MMIC. During transmission
all signals in digital form phase
the shift required for reception and transmission can be digitally performed by delaying signals to varying degrees
towards or away from the individual antenna elements.
This approach removes the need for
use of analog phase shifters in
PPM and allows you to get without much effort
the possibility of digital control of the position of the DNA with an accurate time delay.
The main advantages of digital radar
associated with the possibility of a significant reduction in the size of the required analog
receiving equipment and with architectural
flexibility due to the possibility of remote placement of some components
Radar in places remote from the antenna on board
plane or ship. Their disadvantages include the high cost of the ones used in them.
high-speed analog-to-digital or digital-to-analog converters with large
dynamic range. Also required
large computing power of the order
teraflop (1012 op / s).
PHOTONICS
In recent years, the concept of use in radars has become widespread.
photonics. The term "photonics" is somewhat inaccurate. It is used to refer to
optical means, i.e. lasers, optical
communication lines, mirrors, lenses, various hybrid
components that combine optical, electro-optical and electronic elements into monolithic structures known as optoelectronic integrated circuits (OEIC - Optoelectronic
Integrated Circuit).
With regard to radar, photonics refers to
usually to broadband analogue optical propagation of microwave signals and
real-time delay control. Placement of microwave signals on optical media
completely changes the physics of propagation
signals, therefore inconvenient, often large and expensive waveguide structures, traditionally used for distribution
Microwave signals from the PAR elements and back are replaced by miniature, lightweight and cheap
fiber-optic communication lines.
There are still many unresolved problems in this matter. R&D for the improvement and development of photonic technology
components continue.
Photonic radars will compete in the future with digital
Radars, the concept of which also uses
photonics in a more perfect form in the form
fiber-optic digital communication lines.
As with coherent optical processing
signals in synthetic aperture radar
the rate of development of digital technology is currently exceeding the rate of development of photonics. Given the state of the art of these two
technologies, digital methods are getting more
wide use. Despite synchronization problems, digital stations are more flexible and flexible. Although photon radar may find applications
in the field of highly specific tasks, it is unlikely
will it provide a solution to the general tasks inherent in
digital methods.
COMPLEX
PURPOSE CHARACTERISTICS
Collecting with additional sensors
information about the goal, according to experts,
is one of the important trends in the improvement of electronic weapons,
solving problems of target recognition. Such a possibility can be realized by observing the target using either one
of the same sensor in different spectral
ranges, or several sensors located in different places. In technology
Both methods are practiced by radars. In a number of heads
homing, currently being developed, the first method is used - observation in several widely spaced
spectral bands to obtain complementary target information. Method two
used in automated systems
air defense control of the operational compound of the Navy
(CEC - Cooperative Engagement Capability), in which many ship and aircraft radars
united by modern communication systems
into a single information network. By distributing
data from all radars located in a certain area, and synthesizing results to eliminate duplication or resolve explicit
contradictions, it is possible to create a single radar display of the space of combat
action.
BISTATIC
AND MULTISTATIC
SYSTEMS
The provision of the US Armed Forces with new types of active radars is limited by capabilities
use of noise-immune sources
radio frequency radiation. Many active
tactical radars, in addition to their basic functions,
can jointly or autonomously execute
function of target illumination in bistatic or
multistatic modes. For military purposes, several bistatic radars have been developed,
but in general they are found to be less effective,
than conventional monostatic. However, the stations
in which the receiver and transmitter are located
in one place are good targets
for complete destruction by anti-radar missiles. Multistatic radar systems that use existing geographically dispersed emitters for such attacks
invulnerable.
It is possible that the subsequent development of this
field of technology can provide the Navy
new types of radars that do not require super-powerful transmitters and function
almost completely hidden. This requires a significant amount of additional
research.
PASSIVE FORMATION
IMAGES
Passive imaging is based on the use of the intrinsic radio emission of various objects and
from the external natural environment of background illuminating radiation, as it happens in
eyes or television cameras. The same principle can be adopted for imaging with radar and means of working
in the range of millimeter waves. According to American specialists, this will make it possible to make a technological breakthrough in the field of creating tools that provide an opportunity
observing objects hidden by a smoke screen,
foliage and camouflage. The surfaces of natural objects emit electromagnetic energy in the radio frequency range, spectral
whose density depends on temperature and
emissivity. Highly reflective metal surfaces
(hence low emissivity) reflect signals well from all other
natural sources of radiation, of which
the most significant is the sky, and therefore
look in comparison with the background of the earth's surface as a very cold spot. The presence of such
irregularities with a sufficient antenna aperture, providing a narrow beam pattern and high
permission, allows for passive
formation of radar images.
ELECTRO-OPTICAL SYSTEMS
The value of optical
area of the electromagnetic spectrum, the use of which in difficult weather conditions
assessed as limited. However, its capabilities are extremely useful for creating
2D and 3D images with high
spatial resolution at small
observation apertures in conditions
good visibility. As high-precision weapon systems with low side
damage optical systems become necessary for automatic recognition
and target selection, identification of guidance points,
high-precision target designation and guidance at the end of the trajectory, as well as for routine observation.
Passive imaging. The efficiency of modern optics sharply increases with the development of providing
electronic computers and semiconductor microelectronic technology.
New materials are being developed for semiconductor detectors in the optical spectral range. This allows you to quickly
develop technologies and create flat focal imaging matrices
and use semiconductor integrated
circuits with a large number of elements of photodetectors and electronic readout circuits from
them signals.
The rate of increase in the number of picture elements on an integrated circuit chip
is exponential. Wherein
the most promising are visible
and near infrared spectral ranges
due to the fact that highly efficient photodetectors can be manufactured for them.
silicon based. Using readout electronics based on it, it is possible to manufacture
monolithic flat matrix of photodetectors
as a technological basis for obtaining high-definition images, widely used in the television industry, for
production of portable digital video cameras that record image and sound.
MULTI AND HYPERSPECTRAL
SIGNATURES
Another trend inherent in radar technology and optics is
increased interest in the collection of complex characteristics or the so-called multidimensional
object signatures for a more reliable understanding of images. Dual-mode heads
homing missiles that use
two different infrared (IR) ranges,
selected in accordance with the conditions of their operation, have demonstrated high efficiency in the conditions of the use of infrared devices
counteraction and significant reduction
number of false alarms caused by
phenomena such as glare from the sun.
This article is based on
analysis of publications in foreign scientific, technical and periodicals, materials of exhibitions, international conferences and
symposia as well as official communications
government bodies and firms
United States regarding information about the used and
promising technologies in the field of shipborne electronic weapons systems.
In particular, research materials from the US National Academy of Sciences, research organizations and laboratories were used.
United States Navy, Industry and University"
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