Dynamic range,sensivity,resolution ,noise ,eirp ,polosa signala...

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Dynamic range,sensivity,resolution ,noise ,eirp ,polosa signala...

milstar: 1.Receiver dynamic range --------------------------------- Stat`ja Watkins-Johnson /razr. i postawshik priemnikow spionaza wj8617 w 80-90 godi/ http://www.triquint.com/prodserv/tech_info/docs/WJ_classics/vol14_n1.pdf http://www.triquint.com/prodserv/tech_info/docs/WJ_classics/vol14_n2.pdf http://www.triquint.com/prodserv/tech_info/WJ_tech_publications.cfm Dinamicheksij diapazon radara AN/FPQ-6 programmi Appolo -bolee 120 db Antenna -8.8 metra D ,5.4-5.9 ghz ,4.8 kwt srednej,3 megawatt impulsnoj moschnosti , dalnost bolee 60 000 km ,pri raz. +-2 metra ,IF-30 mgz,polosa signala -1.6 mgz http://en.wikipedia.org/wiki/AN/FPQ-6 http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680003409_1968003409.pdf ljubitelskij priemnik smotri revue pri polose 400 herz , i ydalenii nesuchej signala pomexi 2000 herz blok. dinamicheskij diapazon -140 db ,chustw -138 db=0.028 microvolta http://www.elecraft.com/ 2. http://www.sandia.gov/RADAR/imageryka.html kollekzija image ot 35 ghz synthetic apperture radar razr.sposobnost' 4 inches -10 sm,100 millimetr polosa signala 2500 mgz Contact: To send feedback or request information about the contents of Sandia National Laboratories' synthetic aperture radar website, please contact: Nikki L. Angus Synthetic Aperture Radar Website Owner Sandia National Laboratories Albuquerque, NM 87185-1330 (505) 844-7776 (Phone) (505) 845-5491 (Fax) nlangus@sandia.gov http://www.sandia.gov/RADAR/movies.html kollekzija video s SAR Ku band i raz sposb 300 mm 3. -dbm microvolt conversion http://wa8lmf.net/miscinfo/dBm-to-Microvolts.pdf 0 dbm =224 millivolt dlja 50 ohm -47 dbm = 1 millivolt = 1000 microvolt -107 dbm = 1 microvolt -127 dbm = 0.1 microvolt -147 dbm = 0.01 microvolt -167 dbm = 0.001 microvolt = 1 nanovolt pri komnatnoj temperature tepl. schumi -174 dbm/ herz

Ответов - 76, стр: 1 2 3 4 All

milstar: Minimalnaja polosa realizowannaja w woennix sistemax swjazi ( navigazija kak chastnij sluschaj swjazi) ###################################################################### 1. USA Navy very low frequency -50 bit/sek The Navy shore VLF/LF transmitter facilities transmit a 50 baud submarine command and control broadcast Polosa signala primerno 50 hertz http://www.fas.org/nuke/guide/usa/c3i/vlf.htm 2. Milstar/AEHF (zap 14.08.2010) -75 bit/sek .Polosa primerno 75 herz http://www.as.northropgrumman.com/products/aehf/assets/AEHF_datasheet_2010_.pdf 3. Military GPS Carrier track loop bandwidth = narrowband = 2 Hz http://wstiac.alionscience.com/pdf/Vol3Num4.pdf 4 .Sistemi troposfernoj swjazi .Toze chto i milstar/AEHF 75 bit/sec polosa 75 herz Est sowm. terminali troposkatter/sputnik http://www.gdsatcom.com/troposcatter.php W sluschae ochen wisokix pomex snizenie polosi s 50 hertz do 0.5 hertz ponizaet neobx.minimum signala na 20 db/100 raz/ -174db/hertz dlja polosi 1 herz pri 290 K -164 db dlja 10 herz -154 db dlja 100 herz --------------------------- " ... Gruschi ,w maximalnom tempe widwigajtes k Ygomonu" -Napoleon 1 iz 1024 wozmoznix fraz ,kotorie mozno peredat 10 bitnim pismom za 10 sek (polosa 1 hertz) ili 100 sek (polosa 0.1 hertz) w rezime naibolschej boewoj ystojchiwosti ( wisokaja ionizacija atmosferi ot serii podriwow yabch) #################################################

milstar: free space loss Milstar =- 210.8 db http://www.mitre.org/work/tech_papers/tech_papers_99/airborne_demo/airborne_demo.pdf A= -92.5 -20log(fd) f w gigaherz d w km 41000 km dlja maximum ydalenija GEO 20 ghz A=-210.776 db

milstar: 9S32 RLS The low noise receiver (noise factor 3 dB) uses an electrostatic amplifier tube that can withstand leakage powers of several hundred Watts without damage and with near-instantaneous recovery to full gain and sensitivity when the transmitted pulse ends. ***************************************************************************** 7volt na 50 omnuju antennu eto 1 watt na wxode priemnika 70 volt eto 100 watt [BR]http://www.ausairpower.net/APA-Russian-SAM-Radars-DKB.html#mozTocId551440 Thus, the loss attributed to solid-state protective devices commonly required in Western radars is also absent.

milstar: Dlja sravnenija s priemnikom S-300V ,kotorij rabotaet ,kogda na wxode bolee 100 volt - ########################################################################## Nize na linke sxema woennogo GPS priemnika ,kotorij rabotosposben pre prewischenii pomexi nad signalom na 120 db ########## http://nu-trek.com/nu-trek/rf-applications.html/#RF%20receiver ... no clipping nastupaet pri 0 dbm ili daze mensche 0 dbm = 0.224 volta

milstar: The front-end receiver amplifiers developed by Airborne Instrument Laboratory are cryogenically cooled parametric amplifiers, or paramps. These efficient paramps are major contributors to Haystack’s high radar sensitivity, achieving a system noise temperature of 35 K. ########### http://www.ll.mit.edu/publications/journal/pdf/vol12_no2/12_2widebandradar.pdf

milstar: http://www.phys.hawaii.edu/~anita/new/papers/militaryHandbook/rcvr_sen.pdf RECEIVER SENSITIVITY / NOISE

milstar: http://highfrequencyelectronics.com/Archives/May08/HFE0508_Cannata.pdf

milstar: http://callisto-space.com/en/products/miniature-cryogenic-low-noise-amplifiers.html mensche 1 kg Miniature Cyrogenic Low Noise Amplifiers The latest addition to Callisto’s range of cryo LNA products is our Miniature X-Band. This LNA is intended for use on tracking X-band ground station antennas operating around 8 GHz for reception. The LNA has two operating modes; normal and “turbo”. The difference between the two modes is the noise figure performance. In “turbo” mode the noise figure is significantly reduced compared to “normal” mode by cryo-cooling the LNA circuit. The intended application of this LNA is for critical data communications. By switching to the “turbo” mode the User can counter-act the effects of fading on his communications link by the improvement in his ground terminal G/T. When the link has returned to normal conditions the LNA can be switched back to “normal”, the cryo-cooler is switched off and the LNA circuits work at ambient temperature. A typical fade event can be caused by severe weather, for example. Another application for this dual mode LNA could be for ground stations used for in-frequent critical operations such as LEOP. Cooling of the LNA circuit to very low temperatures is achieved using a miniature Stirling cycle cryo-cooler. These high efficiency refrigerators have been developed to serve various applications most notably for Infra-Red detector cooling in military equipment. As such, these miniature cryo-coolers are designed for high reliability and robustness.

milstar: CIA priemnik http://watkins-johnson.terryo.org/Documents/Manufacturers/WJ/Data%20sheets/WJ-8617B%20data%20sheet.pdf

milstar: Miniature receiver with high dynamic range from Lincoln laboratory http://www.ll.mit.edu/publications/technotes/TechNote_mini-RFReceiver.pdf

milstar: http://www.gdsatcom.com/Electronics/Data%20Sheets/14368_C.pdf X-Band Low Noise Amplifiers LXA-7500 Series

milstar: http://www.callisto-space.com/en/products/compact-cryogenic-low-noise-amplifiers.html Noise temperatur 20°K

milstar: https://www.maximintegrated.com/en/app-notes/index.mvp/id/1929

milstar: In the case of a production line that produces satellite receivers, it may be quite easy to reduce the noise figure 1 dB by adjusting impedance levels or carefully selecting specific transistors. A 1dB reduction in noise figure has approximately the same effect as increasing the antenna diameter by 40%. But increasing the diameter could change the design and significantly raise the cost of the antenna and support structure http://cp.literature.agilent.com/litweb/pdf/5952-8255E.pdf Figure 1-2(a) shows an example situation at the input of an amplifier. The depicted signal is 40 dB above the noise floor: Figure 1-2(b) shows the situation at the amplifier output. The amplifier’s gain has boosted the signal by 20 dB. It also boosted the input noise level by 20 dB and then added its own noise. The output signal is now only 30 dB above the noise floor. Since the degradation in signal-to-noise ratio is 10 dB, the amplifier has a 10 dB noise figure

milstar: Ведь если корпус спутника неподвижен, то детали его, обращенные к Солнцу, могут нагреться (при малом контакте с корпусом) до 100° С, а части, находящиеся в тени, охладятся до -150° С и ниже http://epizodsspace.airbase.ru/bibl/zaytsev/sput-kosm/01.html ----------------- ! Шумовая температура антенны РЛС

milstar: This can be explained in Figure 7 which shows how the Friis equation is used to calculate the noise factor for cascaded gain stages. Notice that high gain in the first stage reduces the contribution of the noise factor of the second stage—the noise factor of the first stage dominates the overall noise factor. http://www.analog.com/media/en/training-seminars/tutorials/MT-006.pdf

milstar: http://www.satsig.net/noise.htm Noise temperature, Noise Figure (NF) and noise factor (f)

milstar: A 1.57-GHz RF Front-End for Triple Conversion GPS Receiver whose IF frequencies are 179, 4.7, and 1.05 MHz http://vergina.eng.auth.gr/electronicslab/files/tel_electr/00658621.pdf

milstar: 1st IF- Amplifier The first IF- Amplifier is a relatively narrowband amplifier with a high gain. The first IF has a relatively high value, e.g. 500 Megahertzes. This will cause a high effort of shielding measures. Automatig gain control measures will be realized here at least. Second converter The first IF gets down mixed with a fixed frequency from the 2nd Local Oszillator to the second IF. Second IF- Amplifier The second IF- Amplifier is a relatively narrowband amplifier with a very high gain. The frequency is a standard-value between 60 up to 75 Megahertzes. This frequency can be processed uncomplicated. The IF- Amplifier of a radar receiver determines the gain, signal-to-noise ratio, and effective bandwidth of the receiver. The typical IF amplifier usually contains from three to ten amplifier stages. The IF amplifier has the capability to vary both the bandpass and the gain of a receiver. The second IF- Amplifier is often a logarithmic amplifier. A large signal does not saturate the logarithmic amplifier; rather, it merely reduces the amplification of a simultaneously applied small signal. A small echo signal can often be detected by the logarithmic receiver when a normal receiver would be saturated. http://www.radartutorial.eu/09.receivers/rx07.en.html

milstar: Overview of Radar DMTI Processing The SPS-48E radar (Fig. 1) uses a triple conversion receiver. ########### The system is wideband until the second intermediate frequency (IF) conversion, where the individual beams are bandpass filtered and separated. Since three beams are used in the DMTI, there are three coherent oscillator frequencies (one for each beam) in the final conversion of the receiver (final IF is about 1.5 MHz). ################ A single analog-to-digital (A/D) converter is used for each beam. In-phase and quadrature (I/Q) data are developed based on samples that are spaced at multiples of 90° at the IF frequency. The interpolation filter develops the I/Q estimates from A/D samples (see the boxed insert, Intermediate-Frequency Sampling Technique). The I/Q data preserve the amplitude and phase of the IF radar return. The amplitude of the radar return is computed as ( ). I Q 2 2 + The phase of the return is computed as tan21 (Q/I). From pulse to pulse, a phase progression will be seen on moving targets due to Doppler, and no phase progression will be seen on stationary reflectors. It is this phase progression on moving targets that allows such targets to be separated from stationary reflectors (clutter). To remove clutter and pass targets, DMTI filters are employed in each beam independently. A bank of digital filters is used to cover the region between low velocity (small phase shift per pulse) and higher velocity (near 360° phase shift per pulse). Targets moving at speeds such that they present more than a 360° phase progression per pulse are said to be velocity ambiguous, since the radar pulse repetition interval causes aliasing. For example, a phase progression of 400° per pulse appears exactly as a phase progression of 40° per pulse. To avoid velocity blinds (i.e., targets moving at speeds such that their phase progression is 360° per pulse, thus appearing as 0° per pulse), the pulse repetition frequency is jittered on a burst-to-burst basis. This ensures that the phase progression presented by the target will vary on a burst-to-burst basis, and thus the target will not be velocity blinded on all bursts http://www.jhuapl.edu/techdigest/TD/td1803/roul.pdf Description The AN/SPS-48G is a long-range, three-dimensional (3D) Air Search Radar that will be installed on CVN, LHA, LHD, and LPD 17 class ships. The AN/SPS-48G is used to find full volumetric detection data for Ships Self Defense System and the Cooperative Engagement Capability (CEC), Air Intercept Control, Anti-Ship Cruise Missile detection including Low Elevation and High Diver targets, backup aircraft marshalling, and the new Hazardous Weather Detection and Display Capability. http://www.navy.mil/navydata/fact_display.asp?cid=2100&tid=1250&ct=2 AN/SPS-48E - Compared to the C variant, the SPS-48E has twice the radiated power, increased receiver sensitivity, four stage solid-state transmitter, half the components of a -48C and built-in testing for easier diagnostics. Originally developed as part of the New Threat Upgrade (NTU) Program to support the SM-2 Launch On Search (LOS) capability. 1975 under the Guided Missile Frigate Anti-Air Warfare Modernization Program. The AN/SPS-48E included a digital receiver and signal processor that could automatically detect and track very small targets, even when jammed. It was included in the New Threat Upgrade of the 1980s. The deployment of the AN/SPY-1 and the end of the Cold War led to the decommissioning of a large number of such ships, and many of these vessels AN/SPS-48 sets were reused on aircraft carriers and amphibious ships, where it is used to direct targets for air defense systems such as the Sea Sparrow and RIM-116 SAM missiles. Existing sets are being modernized under the ROAR program to AN/SPS-48G standard for better reliability and usability. ################# INTERMEDIATE-FREQUENCY SAMPLING TECHNIQUE To develop in-phase (I) and quadrature (Q) data, the SPS-48E radar uses an intermediate-frequency (IF) sampling technique with an IF bandwidth of approximately 400 kHz, IF center frequency of about 1.5 MHz, and analog-to-digital (A/D) sampling frequency of 6 MHz. There is a precise 4:1 relation between the IF sample frequency and the IF center frequency. If modulation effects across the received pulsewidth are ignored, the echo may be thought of as several cycles of a sine wave. The sine wave is sampled at four times its rate, i.e., every 90°. Therefore, alternate samples will be in quadrature with each other. To account for modulation effects across the pulse, one sample is defined to be “I”; two leading and two trailing samples are combined by the following equation to create the “Q” sample (s): 180° phase shift 90° phase shift Time Q ssss =− − + + 1 16 9 16 9 16 1 16 1234 Q I QI Q I Q s s Is s −− −− 1234 This technique provides accuracy acceptable for the clutter cancellation requirements of the SPS-48E lowelevation-mode DMTI. If higher clutter cancellation is required, a more elaborate finite impulse response filter for both the I and the Q channel is required. The advantage of the current technique is that I/Q data are developed with only a single A/D converter. The two baseband analog channels in a conventional receiver are not required, and aliasing due to channel gain mismatch is avoided. Amplitude modulation effects across the received pulse do, however, cause some degradation.

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