Operazionnie ysiliteli ,ZAP/AZP & (продолжение)

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Operazionnie ysiliteli ,ZAP/AZP & (продолжение)

milstar: 1941: First (vacuum tube) op-amp An op-amp, defined as a general-purpose, DC-coupled, high gain, inverting feedback amplifier, is first found in US Patent 2,401,779 "Summing Amplifier" filed by Karl D. Swartzel Jr. of Bell labs in 1941. This design used three vacuum tubes to achieve a gain of 90dB and operated on voltage rails of ±350V. ###################################################### It had a single inverting input rather than differential inverting and non-inverting inputs, as are common in today's op-amps. Throughout World War II, Swartzel's design proved its value by being liberally used in the M9 artillery director designed at Bell Labs. ######################################################################### This artillery director worked with the SCR584 radar system to achieve extraordinary hit rates (near 90%) that ####################################################################### would not have been possible otherwise.[3] ########################### http://en.wikipedia.org/wiki/Operational_amplifier

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milstar: Another benefit of sampling at higher frequencies is that in systems where large bandwidths are not required, the high-IF sampling of the faster converters can be used to gain SNR performance using of decimation. When decimating an A/D converter's output, you essentially throw away a periodic number of samples. Every time the output is decimated by a factor of two, where half the samples are removed, the SNR is improved by three dB. The cost is that the effective sample rate is now halved and, therefore, so is the available bandwidth. For example, suppose a system requires only 20 MHz of bandwidth, but the form factor needs to be small. It is possible with today's fastest 14-bit A/D converter to sample this 20 MHz of bandwidth at 200 MSPS with the center input frequency being 350 MHz, a reasonable output for an RF-to-IF mixing stage. Choosing this frequency for the IF centers the signal band in the converter's Nyquist zone, which spans 300 to 400 MHz. With the signal bandwidth residing in the 340-360 MHz range, the AAF has 40 MHz on either side of the signal to operate. From the contour plots in Figure 1, a converter can achieve 69 dBFS SNR and 73 dBc SFDR at this sample rate and input frequency. With only 20 MHz of bandwidth to sample, a DDC's numerically controlled oscillator (NCO) could mix the signal to the I and Q bands. In turn, this allows the 200 MSPS sample rate to be decimated by a factor of four to an effective sample rate of 50 MSPS, increasing the SNR by 6 dB to 75 dBFS. http://www.eetimes.com/design/industrial-control/4009976/Using-high-IF-sampling-A-D-converters-beyond-baseband-frequencies Using high-IF sampling A/D converters beyond baseband frequencies Charles Sanna, Product Marketing Engineer, High-Speed ADCs, Texas Instruments Incorporated

milstar: http://www.analog.com/static/imported-files/circuit_notes/CN0140.pdf High Performance, Dual Channel IF Sampling Receiver

milstar: http://www.armms.org/images/conference/f_cabanes_e2v_high_speed_adc_10b2_2g.pdf

milstar: http://people.ece.cornell.edu/wes/Projects/AD_notes/SEMINARS/NARROW.PDF%3b1 IF-Sampling Receiver Design Example Dual Channel Gain-Ranging ADC with RSSI: AD6600 Optimized for “Narrowband”, IF-Sampling Receivers Sampling to 20 MSPS; digitizes Analog inputs to 70- 250 MHz 90+ dB Dynamic Range: 30 dB variable attenuation & 60+ dB in ADC 60+ dB in ADC chto malo ...s ARU terjaetsja slabij signal #############################

milstar: http://webench.national.com/rd/RD/RD-179.pdf 2.0 Features Key Features of the SP16160CH1RB High-IF Sub-Sampling Receiver Reference Design Board Ўц Demonstrates a high-IF sub-sampling subsystem architecture used in wireless infrastructure systems Ўц Configured for a 20 MHz input bandwidth centered at 192 MHz Ўц Configured with a low-noise, 153.6 MSPS CMOS sampling clock Ўц Featured Products Include: ЎЄ ADC16DV160 dual 16-bit, 160 Megasample per second (MSPS) ADC with parallel LVDS outputs ЎЄ LMH6517 Digitally-controlled, Variable Gain Amplifier (DVGA) with 31.5 dB gain range in 0.5 dB steps ЎЄ LMK04031B low-jitter precision clock conditioner consisting of cascaded phase locked loops (PLLs), an internal voltage controlled oscillator (VCO) and a distribution stage ЎЄ Several energy-efficient power management ICs Ўц Large-signal (-1 dBFS) performance for a 192 MHz input signal: ЎЄ SNR = 71 dBFS ЎЄ SFDR > 80 dBFS Ўц Small-signal (-6 dBFS) performance for a 192 MHz input signal: ЎЄ SNR = 72.7 dBFS ЎЄ SFDR > 92 dBFS Ўц 200 kHz channel performance for base-station receiver applications: ЎЄ SNR = 99 dBFS under normal conditions ЎЄ SNR = 94 dBFS under blocking conditions ЎЄ SFDR > 90dBFS under blocking conditions Ўц Total integrated jitter < 200 fs

milstar: JPL 2010 I. Introduction To address the future telemetry, navigation, and radio science needs of the Deep Space Network (DSN), considerable eort at JPL has been directed toward the development of a wideband ground receiver, intended to supplement and expand the capabilities of the currently operational Block V Receiver (BVR). Among the challenges encountered in this eort has been the need to process both high data rate telemetry (well in excess of 150 Mbps), as well as telemetry from very low-rate missions. Another key element of this work has been the selection of a processing platform that is well-suited to rmware and software recongurability. These objectives have led to the development of the Recongurable Wideband Ground Receiver (RWGR): a variable data rate, http://ipnpr.jpl.nasa.gov/progress_report/42-180/180D.pdf The RWGR is an intermediate frequency (IF) sampling receiver that operates at a xed input sampling rate of 1:28 GHz. It is designed to accommodate a continuous range of data rates from 4 Bd (symbols/second or baud) ######################################################### to 320 MBd, and is capable of processing 500 MHz of bandwidth. ######################################## In contrast, the BVR operates at a sample rate of 160 MHz and can only accommodate a bandwidth of 72 MHz.

milstar: SDR primer (raschet priweden) http://www.nsarc.ca/hf/perseus.pdf http://www.microtelecom.it/perseus/

milstar: This article shows how averaging the outputs of multiple high-speed ADCs can be used to improve data converter SNR. While an alternate technique of oversampling the input signal using faster ADCs is possible, the averaging approach seems preferable because faster ADCs which enable oversampling may not be available, and lower-speed ADCs used in an averaging approach may have better initial SNR specifications and lower power. This article examined the averaging approach. Hardware was built to measure the SNR performance of using two and three high-speed (190 Msps) ADCs to sample an input signal in parallel. We found that special care must be given to the impedance transformation of the input matching circuit, as a lot of signal attenuation and distortion can be caused by the impedance mismatch. http://www.eetimes.com/design/automotive-design/4009960/Multiple-A-Ds-versus-a-single-one-pushing-high-speed-A-D-converter-SNR-beyond-the-state-of-the-art

milstar: sistema swjazi Milstar 44ghz/20 ghz http://www.boeing.com/defense-space/space/bss/factsheets/government/milstar_ii/milstar_ii.html http://www.mitre.org/work/tech_papers/tech_papers_99/airborne_demo/airborne_demo.pdf http://www.as.northropgrumman.com/products/milstar/assets/Milstar_Digital_Processing.pdf To perform these complex functions, the MDR digital processing subsystem relies on 14 custom application-specific integrated circuits and 397 large-scale integrated (LSI) circuits, all fabricated in CMOS technology. This figure represents a decrease of 37 percent from the 630 custom LSI circuits required for each LDR payload. 1 IF (pch) = 7.4 ghz 2. IF verojatno ot 70 mhz do 280 mgz t.e. vozmozno ispolzowanie 16 bit ADC s SNR na 70 mgz 80 db LTC 2217/16/15 Linear technology ili AD9467 200/250 msps i 73-74 db SNR na 170 -280 mgz Radio Frequency Subsystem (RFSS) The RF subsystem includes the processing and receiving components and the downlink group. The processing and receive group performs the following four payload functions: amplifies, dehops, and downconverts the EHF waveform to the first intermediate frequency (IF) via the low-noise amplifier/downconverter; receives, amplifies, downconverts, and switches the first IF to the second IF for input to one of four demodulator groups of eight channels each; employs a differential phase shift key (DPSK) to modulate and upconvert onto a hopped SHF carrier for input to the downlink group; and generates and distributes the hopping and fixed local oscillators for the antenna coverage subsystem, digital subsystem and RFSS. The downlink group amplifies, filters and switches, on a hop-by-hop basis, the SHF waveform to any of the eight antennas. The SHF amplifiers are triple-redundant traveling wave tube amplifiers. Switching capability is provided by a high speed/high power beam select switch. http://www.linear.com/product/LTC2216 LTC2217 - 16-Bit, 105Msps Low Noise ADC http://www.linear.com/product/LTC2217 AD9467: 16-Bit, 200 MSPS/250 MSPS Analog-to-Digital Converter http://www.analog.com/en/analog-to-digital-converters/ad-converters/ad9467/products/product.html With the MDR payload, Milstar 6 is capable of processing data at speeds up to 1.5 megabits per second. With the LDR payload, the satellite can transmit voice and data at 75 to 2400 bits per second. After testing and systems evaluation, the $800 million Milstar 6 ################## T.e. bez NIOKR podobnij sputnik segodnja budet stoit segodnja bolee 1 mlrd $ za 1 is expected to be fully operational within two months and will aid military forces worldwide by ensuring critical information reaches its destination quickly and securely. The Milstar 6 satellite is expected to last at least ten years. Each Milstar satellite weighs about 10,000 pounds and can be described as a "switchboard" in space, directing the traffic it receives from terminal to terminal anywhere on Earth http://findarticles.com/p/articles/mi_m0PAA/is_2_28/ai_107699568/

milstar: http://www.electrorent.com/pdf/GeneratingAdvancedRadarSignals.pdf http://www.electrorent.com/pdf/GeneratingAdvancedRadarSignals.pdf

milstar: David A. DeBell and Thomas S. Diviney Northrop Grumman Corp. (USA) ------------------------------------------ IF (intermediate frequency) sampling is a method of sampling the received radar waveform out of the IF channel directly, without mixing to baseband, using a single A/D converter. ------------------------------------- The sampling rate needed is a multiple of the bandwidth of the IF filter, of the order of 3 times the -3 dB bandwidth. -------------------------------------------------------------------------------------------------------------------------------- IF filter skirt attenuation limits aliasing effects and permits apparent undersampling of the IF frequency. Stretch processing is the method of matching the radar's LO frequency ramp rate (linear FM) to the transmit waveform's `chirp', in order to limit the IF bandwidth requirement to a value much less than the RF bandwidth and thus permit a lower rate of sampling. ----------------------------------------------------------------------------------------------------------------------------------------------------------- The combination of IF sampling and stretch processing is advantageous because A/D samplers are now able to operate at adequately short sample- and-hold aperture times, for use at IF frequencies, with a good number of bits resolution, and stretch processing can use narrow IF bandwidths. ------------------------------------------------------------------------------------------------------------------------------------------------------------------- Therefore, high range resolution can be achieved at a lower cost than with quadrature channels at baseband and dual A/D's. Added benefits are the elimination of I-Q imbalance effects, A/D DC offset effects, and the need for calibration of these effects. Some A/D saturation can also be tolerated. A Fast Fourier Transform of the real sample data set is easily converted to an inphase and quadrature output data set for further operations. The paper goes into the equations and methodology of such a radar system and delineates the hardware differences between the baseband approach and the IF sampling approach. © 2004 COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. http://spiedigitallibrary.org/proceedings/resource/2/psisdg/2747/1/98_1?isAuthorized=no

milstar: Stretch processing relieves the signal processor bandwidth problem by giving up all-range processing to obtain a narrow-band signal processor. If we were to use a matched filter we could look for targets over the entire waveform pulse repetition interval (PRI). With stretch processing we are limited to a range extent that is usually smaller than an uncompressed pulse width. Thus, we couldn’t use stretch processing for search because search requires looking for targets over a large range extent, usually many pulse widths long. --------------------------------------- We could use stretch processing for track because we already know range fairly well but want a more accurate measurement of it. ------------------------------------------------------------------------------------------------------------------------------------------------------- We must point out that, in general, wide bandwidth waveforms, and thus the need for stretch processing, is “overkill” for tracking. Generally speaking, bandwidths of 1s to 10s of MHz are sufficient for tracking -------------------------------------------------------------- One of the most common uses of wide bandwidth waveforms, and stretch processing, is in discrimination, where we need to distinguish individual scatterers on a target. Another use we will look at is in SAR (synthetic aperture radar). Here we only try to map a small range extent of the ground but want very good range resolution to distinguish the individual scatterers that constitute the scene. Thus, the stretch processor encounters a SNR loss of h T   relative to the matched filter. This means that we should be careful about using stretch processing for range extents that are significantly longer of the transmit pulse width. At first inspection it appears as if stretch processing could offer better SNR than a matched filter, which would contradict the fact that the matched filter maximizes SNR. This apparent contradiction is resolved by the stretch processor constraint imposed by Eqution (15). Specifically, h R T     . The constraint if Equation (42) also demonstrates another reason why stretch processing should not be used in a search function: it would be too lossy. We will assume base-band processing in these discussions. In practice the mixer output will be at some intermediate frequency (IF). The signal could be brought to base-band using a synchronous detector or, as in some modern radars, by using IF sampling (i.e. a digital receiver). In either case, the effective ADC rate (the sample rate of the complex, digital base-band signal) will be as derived here Specifically, we consider a waveform with a bandwidth of 500 MHz and a pulse width of 100 μs. We assume further that the matched filter is matched to the target Doppler. That is, d M f  f . For the first case we consider a typical aircraft range-rate of -150 m/s and for the second case we consider a ballistic missile with a (extreme) range-rate of -7500 m/s. Plots of the matched filter outputs for the two cases are shown in Figure 5 and Figure 6. http://www.ece.uah.edu/courses/material/EE710-Merv/Stretch_11.pdf

milstar: The ARPA-Lincoln C-band Observables Radar, or ALCOR [20], on Roi-Namur, Kwajalein Atoll, Marshall Islands, had a wideband (512 MHz) 10-μseclong linear-FM transmitted-pulse waveform (see the article entitled “Wideband Radar for Ballistic Missile Defense and Range-Doppler Imaging of Satellites,” by William W. Camp et al., in this issue). ALCOR was a key tool in developing discrimination techniques for ballistic missile defense. The wide bandwidth yielded a range resolution that could resolve individual scatterers on reentering warhead-like objects. This waveform was normally processed with the STRETCH technique, which is a clever time-bandwidth exchange process developed by the Airborne Instrument Laboratory [21, 22]. http://www.ll.mit.edu/publications/journal/pdf/vol12_no2/12_2radarsignalprocessing.pdf mixed with a linear-FM chirp and the low-frequency sideband is Fourier transformed to yield range information. For a variety of reasons, the output bandwidth and consequently the range window were limited. For example, the ALCOR STRETCH processor yielded only a thirty-meter data window. Therefore, examination of a number of reentry objects, or the long ionized trails or wakes behind some objects, required a sequence of transmissions.

milstar: This sequential approach was inadequate in dealing with the challenging discrimination tasks posed by reentry complexes, which consist not only of the reentry vehicle, but also a large number of other objects, including tank debris and decoys, spread out over an extended range interval. What was needed was a signal processor capable of performing pulse compression over a large range interval on each pulse. Lincoln Laboratory contracted with Hazeltine Laboratory to develop a 512-MHz-bandwidth all-range analog pulse compressor employing thirty-two parallel narrowband dispersive bridged-T networks built ############################################ out of lumped components, to cover the bandwidth. The resulting processing unit, shown in Figure 3, was large (it filled about seven relay racks) and complex, and it required a great deal of tweaking to yield reasonable sidelobes. During 1972 and 1973, Lincoln Laboratory developed a 512-MHz-bandwidth (on a 1-GHz intermediate frequency [IF]) 10-μsec RAC linear-FM pulse compressor [23].

milstar: http://microelectronics.esa.int/mpd2010/day2/e2v_presentation.pdf EV10AS180A new European 10-bit 1.5GSPS ADC for Space applications -TRP ESA A05528

milstar: http://www.intersil.com/data/fn/fn7574.pdf http://www.intersil.com/products/deviceinfo.asp?pn=ISLA216P25

milstar: Waveform Variations by Mode.Although the specific waveform is hard to pre- dict, typical waveform variations can be tabulated based on observed behavior of a number of existing A-S radar systems. Table 5.1 shows the range of parameters that can be observed as a function of radar mode. The parameter ranges listed are PRF, pulse width, duty cycle, pulse compression ratio, independent frequency looks, pulses per coherent processing interval (CPI), transmitted bandwidth, and total pulses in a Time-On-Target (TOT). Obviously, most radars do not contain all of this variation, but modes exist in many fighter aircraft, which represent a good fraction of the parameter range. Most fighter radars are frequency agile since they will be operated in close proximity to similar or identical systems. The frequency usually changes in a carefully controlled, completely coherent manner during a CPI.8 This can be a weakness for certain kinds of jamming since the phase and frequency of the next pulse is predictable. Sometimes to counter- act this weakness, the frequency sequence is pseudorandom from a predetermined set with known autocorrelation properties, for example, Frank, Costas, Viterbi, P codes.16 A major difficulty with complex wideband frequency coding is that the phase shift- ers in a phase scanned array must be changed on an intra- or inter-pulse basis greatly complicating beam steering control and absolute T/R channel phase delay. Another challenge is minimizing power supply phase pulling when PRFs and pulsewidths vary over more than 100:1 range. MFAR systems not only have a wide variation in PRF and pulsewidth but also usually exhibit large instant and total bandwidth. Coupled with the large bandwidth is the requirement for long coherent integration times. This requirement naturally leads to extreme stability master oscillators and ultra low-noise synthesizers.44 http://www.scribd.com/doc/17533868/Chapter-5-Multi-Functional-Radar-Systems-for-Fighter-Aircraft 5.12 MULTIFUNCTIONAL RADAR SYSTEMS FOR FIGHTER AIRCRAFT 1.Real beam map 0.5 -10 mgz 2.Doppler beam sharp 5-25 mgz 3. SAR 10 -500 mgz 4.A-S range 1-50 mgz 5.PVU 1-10 mgz 6.TF/TA 3-15 mgz 7.Sea surface search 0.2 -500 mgz 8.Inverse SAR 5-100 mgz 9. GMTI 0.5-15 mgz 10.Fixed target track 1-50 mgz 11.GMTT 0.5 -15 mgz 12.Sea Surface track 0.2-10 mgz 13.Hi power Jam 1-100 mgz 14.CAl/A.G.C 1-500 mgz 15A-S data link 0.5-250 mgz T.e dlja bolschinstwa funkzij dostatochen AD9467 16 bit ADC 250 msps s Fin do 300 mgz Realnij dinamicheskij diapazon -74 db, ENOB -12 bit 250 msps eto polosa 125 mgz Dlja RLS tipa MMW,Don-2N,Haystack s polosoj signala po 2000 mgz -8000 mgz mozno rassmatriwat 12 bit (ENOB -9.3 bita) National s 3.6 gigasample(sdwoennij) i Fin do 1.5 ghz , E2V 12 bit ,1.5 gsps ili 8 bit maxtek 20 gigasamples ( ENOB 6.6 bit do 5 ghz) T.e. dinamicheskij diapazon nize , polosa signala wische From an MFAR point of view, the important parameters are volumetric densitieshigh enough to support less than 1/2 wavelength spacing; radiated power densities highenough to support 4 watts per sq. cm.; radiated-to-prime-power efficiencies greaterthan 25%; bandwidth of several GHz on transmit and almost twice that bandwidth onreceive

milstar: Some modes are used for several operational categories, such as real beam map(RBM), fixed target track (FTT), doppler beam sharpening (DBS), and synthetic aper-ture radar (SAR), used not only for navigation but also for acquisition and weapondelivery to fixed targets.38–43SAR may also be used to detect targets in earthworks ortrenches covered with canvas and a small amount of dirt, which are invisible to EOor IR sensors. Similarly, air-to-surface ranging (A-S Range) and precision velocityupdate (PVU) may be used for weapon support to improve delivery accuracy as wellas navigation.7,9Terrain following and terrain avoidance (TF/TA) is used for navigation at verylow altitudes or in mountainous terrain. Sea surface search (SSS), sea surface track (SST), and inverse synthetic aperture radar (ISAR), which will be described later inthe chapter, are used primarily for the acquisition and recognition of ship targets.Ground moving target indication (GMTI) and ground moving target tracking (GMTT)are used primarily for the acquisition and recognition of surface vehicle targets butalso for recognizing large movements of soldiers and materials in a battle-space. Highpower jamming (HiPwrJam) is a countermeasure available from AESAs due to theirnatural broadband, beam agile, high gain, and high power attributes AESAs also allowlong range air-to-surface data links (A-S Data Link) through the radar primarily formap imagery. Because there may be thousands of wavelengths and a gain of millionsthrough a radar, automatic gain control and calibration (AGC/CAL) is usually requiredfairly often. Modes optimized for this function are invoked throughout a mission http://www.scribd.com/doc/17533868/Chapter-5-Multi-Functional-Radar-Systems-for-Fighter-Aircraft

milstar: ALCOR C-Band ,500 mgz BMDO radar During 1972 and 1973, Lincoln Laboratory devel-oped a 512-MHz-bandwidth (on a 1-GHz interme-diate frequency [IF]) http://www.scribd.com/doc/47868505/Radar-Signal-Processing-by-Purdy-Blankenship-Muehe-Rader-Stern-Williamson

milstar: http://dsp-book.narod.ru/skolnik/7913X_15b.pdf It is recommended that an A/D be evaluated with large signals at all frequencies within the receiver passband to establish that the quantization noise is as low as theoretically expected and that no spurious signals are produced. http://dsp-book.narod.ru/skolnik/7913X_15b.pdf Jitter in the sampling time in the A/D converter also limits MTI performance. If pulse compression is done prior to the A/D or if there is no pulse compression, this limit is TABLE 15.5 Typical Limitation on / Due to A/D Quantization

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