On-line: гостей 0. Всего: 0 [подробнее..]
Добро пожаловать!
Форум ВКО открыт для дискуссий.



АвторСообщение
milstar
moderator




Сообщение: 1860
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 13.11.09 15:19. Заголовок: Operazionnie ysiliteli ,ZAP/AZP & (продолжение)


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

Спасибо: 0 
Профиль
Ответов - 301 , стр: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 All [только новые]


milstar
moderator




Сообщение: 7658
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 31.12.11 19:36. Заголовок: http://dsp-book.naro..


http://dsp-book.narod.ru/skolnik/7913X_03b.pdf

3.11 ANALOG-TO-DIGITAL CONVERTER
Applications. Analog-to-digital converters find numerous applications in
modern radar systems. The trend toward digital processing of radar data has
resulted in a demand for fast converters that are able to convert data in real time.
Digital MTI is an example of a technique requiring such high-speed converters.
Here, the synchronous-detector output is sampled at a rate not less than the receiver
bandwidth, and the digital result is stored in a large digital memory. Data is read
from the memory to allow comparison with corresponding returns from subsequent
radar "looks." The flexibility of this method has permitted MTI velocity response
characteristics previously unobtainable with analog memory devices.
Many tracking radars use a converter to encode the echo in the tracking gate.
In this case, a general-purpose computer provides all computations required to
track a target and to provide range and velocity outputs. Precise data-smoothing
and stabilizing characteristics are provided by the computer.
High-speed converters have been used to encode the height information from
a stacked-beam radar. This permits an arithmetic interpolation of target position.
Errors following conversion are, of course, eliminated.
Another application of converters is in the field of digital recording. This is
used where vast quantities of data are to be analyzed or where an isolated event
is to be analyzed. In this case, the encoded data is stored on magnetic tape. The
results are then analyzed in nonreal time with arithmetic accuracy.

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7659
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 31.12.11 19:37. Заголовок: Performance Characte..


Performance Characteristics
Signal Bandwidth. The digital data used by the terminal equipment is always
sampled. The bandwidth of this "digital signal" is limited to half the sampling
frequency.
Resolution. The resolution of a converter is determined by the number of
bits. For an TV-bit converter, the resolution is Emax/(2^ - 1) if the converter is
truly monotonic, that is, if its response to an analog ramp is a uniform progression
of binary numbers. This characteristic is usually realized with a slowly
changing analog input but must be verified under pulsed conditions.
Dynamic Range. If the A/D converter is sampling the two components of the
echo vector (/ and Q), each component contains half of the noise power and up to
100 percent of the signal power. The dynamic range is the maximum IF signalto-
noise ratio which can be handled by the A/D converter without saturating at
any phase condition.
Dynamic range (dB) = 67V - 9 - 20 log (o/LSB) (3.28)
where N = number of bits including sign
cr = rms noise in / or Q
LSB = least-significant-bit voltage

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7660
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 31.12.11 19:38. Заголовок: numbers introduces a..


numbers introduces an added random error which can be considered as an additional
source of noise, requiring an increase in echo strength to achieve the
desired detection probability if false-alarm probability is maintained constant.
Quantization loss (dB) = 10 log [l + ( M °" - LSB (3-29)
L \ CT / J
Sampling. When the signal bandwidth is so great that the analog voltage
changes significantly from sample to sample, the instantaneous signal may become
distorted by the sampling process.15 A slewing error results when the exponential
charging is incomplete. An entirely separate lag error results from changes in signal
amplitude during the sampling interval. Current flows in the storage capacitor, causing
an IR drop, which is still present when the switch is opened.
An additional error is introduced by the finite opening time of the switch. The
signal tends to be averaged over this interval, and the sampled voltage does not
correspond exactly to the voltage at the instant when the switch starts to open.
The time required to open the switch is sometimes called the aperture time.
Design data specifying the slewing and lag errors is presented in Fig. 3.21. Practical
circuits having RC time constants of 3 ns and sampling intervals of 50 ns have
been used in high-speed A/D conversion. The resultant slewing error is seen to be
less than 0.001 percent, and, at a signal frequency of 0.5 MHz, the lag error is 0.46
percent. It should be emphasized that large sampling errors are not always fatal in a
radar system. For example, in an MTI radar the error will repeat from one interpulse
period to the next in stationary clutter, and it is therefore removed by subtraction in
the canceler.

http://dsp-book.narod.ru/skolnik/7913X_03b.pdf

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7661
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 31.12.11 23:13. Заголовок: http://www.astro.cal..

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7662
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 31.12.11 23:33. Заголовок: When Oversampling an..


When Oversampling and
Averaging Will Work
The effectiveness of oversampling and averaging
depends on the characteristics of the dominant
noise sources. The key requirement is that
the noise can be modeled as white noise.
Please see Appendix B for a discussion on the
characteristics of noise that will benefit from
oversampling techniques. Key points to consider
are [2] [3]:
• The noise must approximate white noise
with uniform power spectral density over
the frequency band of interest.
• The noise amplitude must be sufficient to
cause the input signal to change randomly
from sample to sample by amounts comparable
to at least the distance between two
adjacent codes (i.e.,1 LSB - please see
Equation 5 in Appendix A).
• The input signal can be represented as a
random variable that has equal probability
of existing at any value between two adjacent
ADC codes.
Note: Oversampling and averaging techniques
will not compensate for ADC integral non-linearity
(INL).

http://www.eetindia.co.in/ARTICLES/2003JUN/A/2003JUN19_AMD_PD_AN.PDF?SOURCES=DOWNLOAD


Noise that is correlated or cannot be modeled
as white noise (such as noise in systems with
feedback) will not benefit from oversampling
techniques. Additionally,if the quantization
noise power is greater than that of natural
white noise (e.g.,ther mal noise),then oversampling
oversampling
and averaging will not be effective.
This is often the case in lower resolution
ADC’s. The majority of applications using 12-
bit ADC’s can benefit from oversampling and
averaging.

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7663
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 31.12.11 23:42. Заголовок: http://www.eetimes.c..

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7665
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 01.01.12 19:16. Заголовок: Filter-bank Design f..


Filter-bank Design for Sub-band ADC
Arka Majumdar, Sandipan Kundu, Anindya Sundar Dhar

http://www.stanford.edu/~arkam/letter_subband.pdf

Performance of subband HFB-based A/D converters
Davud Asemani, Jacques Oksman
Department of Signal Processing and Electronic Systems
Ecole Sup´erieure d’Electricit´e (Supelec)
91192, Gif sur Yvette, France
Email: firstname.lastname@supelec.fr

http://hal.archives-ouvertes.fr/docs/00/26/11/64/PDF/IEEE_ISSPa_2007_Sharjah.pdf


Subband architecture for Hybrid Filter Bank
A/D converters
Davud Asemani, Member, IEEE, Jacques Oksman, and Pierre Duhamel, Fellow, IEEE

http://hal.archives-ouvertes.fr/docs/00/29/12/41/PDF/Asemani_Subband_articel_two_columns.pdf


An Oversampled Channelized UWB Receiver
Lei Feng, Won Namgoong
Department of Electrical Engineering
University of Southern California
leifeng@usc.edu, namgoong@usc.edu

http://www.stanford.edu/~arkam/btech_thesis_arka

Filter-Bank Design by Transconductor for Sub-Band
ADC
by
Arka Majumdar, (03EC1024)
Under the guidance of
Prof. Anindya Sundar Dhar

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7666
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 01.01.12 19:41. Заголовок: Two-Dimensional Spat..


Two-Dimensional Spatio-Temporal Signal
Processing for Dispersion Compensation in
Time-Stretched ADC
Alireza Tarighat, Member, IEEE, Shalabh Gupta, Student Member, IEEE, Ali H. Sayed, Fellow, IEEE,
and Bahram Jalali, Fellow, IEEE

http://www.ee.ucla.edu/~tarighat/pdf/jlt_07_ts_adc.pdf

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7667
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 01.01.12 19:45. Заголовок: July 12, 2011 New U..


July 12, 2011

New U.S Export Regulations Reclassify Linear Technology’s 12-bit 200Msps, 14-bit 125Msps and 16-bit 10Msps ADCs for Export to China & Russia

MILPITAS, CA – July 12, 2011 – Linear Technology Corporation is pleased to announce new Export Classification Control Numbers (ECCN) for their families of high performance, high speed ADCs with sample rates of up to 200Msps at 12-bit, 125Msps at 14-bits and 10Msps at 16-bit resolutions. New U.S. Export Administration Regulations have allowed these devices to be reclassified from ECCN# 3A001 to the less stringent ECCN# 3A991. This new classification provides engineers with the capability to use Linear ADCs to develop and export high performance products that can compete freely on the world market.

Linear Technology offers a wide selection of high performance, low power ADCs that maximize desired system performance. For high performance communications applications, the LTC2207-14 14-bit 105Msps ADC achieves 77.3dB SNR and 98dB SFDR. At 16-bit 10Msps, the LTC2202’s 81.6dB SNR and 100dB SFDR performance is ideal for CCD (charge-coupled device) and infrared cameras, x-ray and cytometry/spectroscopy applications.

For the lowest power, designers in China and Russia can now use 14-bit 25Msps to 125Msps solutions such as the dual LTC2145-14 ADC family with parallel outputs, or LTC2268-14 dual ADCs and LTC2175-14 quad ADCs with serial LVDS outputs, which dissipate approximately 1mW per mega sample per second from a 1.8V supply. These ADCs offer unparalleled performance at ultralow power consumption, maintaining portability in such applications as handheld test and instrumentation, radar/LIDAR, medical imaging, PET/SPECT scanners, military radios, smart antenna systems and a range of low-power communication systems.

In addition to a complete portfolio of high performance ADCs, Linear Technology also offers a wide range of RF mixers, including the LTC5569 and LTC5590/91/92/93 family of dual high dynamic range low power mixers, direct conversion modulators and demodulators, VGAs, filters, power detectors, low-distortion amplifiers and ADC drivers to complete the receive signal chain for next-generation wireless base stations and high performance radios. Linear’s customers can depend on a highly skilled team of applications engineers with a deep knowledge of signal chain design to provide design guidance and technical support to ensure a short design cycle and faster time to market.

The ADC product offering can be found at: www.linear.com/hsadc_nolicense.

About Linear Technology

Linear Technology Corporation, a member of the S&P 500, has been designing, manufacturing and marketing a broad line of high performance analog integrated circuits for major companies worldwide for three decades. The Company's products provide an essential bridge between our analog world and the digital electronics in communications, networking, industrial, automotive, computer, medical, instrumentation, consumer, and military and aerospace systems. Linear Technology produces power management, data conversion, signal conditioning, RF and interface ICs, and µModule® subsystems.

LT, LTC, LTM, µModule, and are registered trademarks of Linear Technology Corp. All other trademarks are the property of their respective owners.


http://www.eejournal.com/archives/news/20110712_04/

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7668
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 01.01.12 21:46. Заголовок: Neobxodimo razrabota..


Neobxodimo razrabotat Rossijskuju linejku 16-14-12-10 bit AZP /ZAP

Eto ne tak dorogo ,wsja texnologija dlja etogo dawno est
(topologija wazna)

Video -

http://www.niip.ru/index.php?option=com_content&view=category&layout=blog&id=18&Itemid=23

В настоящее время НИИП является головным предприятием по разработке интегрированной радиоэлектронной системы на основе активных фазированных антенных решёток X- и L- диапазонов для истребителя пятого поколения – эта разработка является основным приоритетом института на ближайшие годы.

http://www.niip.ru/index.php?option=com_content&view=article&id=1&Itemid=6

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7672
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 02.01.12 21:26. Заголовок: http://www.tekmicro...


http://www.tekmicro.com/PDFs/MuPuRF_Radar.pdf

1ghz polosaX-band /centr 9.8 ghz) 150 mm razr .AZP

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7673
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 02.01.12 21:46. Заголовок: http://poulton.net/p..


http://poulton.net/papers.public/2010_cicc_GHz_ADCs.pdf

GHz ADCs: From Exotic to Mainstream
Ken Poulton
Agilent Technologies
Santa Clara, California

Segodnjaserijno wipuskajutsja

10 bit 2.5 GSPB E2V

12 bit 1.5 GSPS E2V
12 bit sdwoennij National 1.8 gsps ( taqkze prodaetsja TI)
12 bit odinarnij TI 1 gsps (neskolko let)

y wsex 12 bitnix SNR ne lutche 57-58 db na 1ghz -1.3ghz
pri GSPS

dlaj srawnenija y 16 bitnix na 70 ghz pri polose signala 20 mhz
i skorosti 100 -125 msps

SNR - 80 DB
############


na 170 -270 mhz pri 200-2500 msps y 16 bit AD9467

SNR 76-73 db

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7674
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 03.01.12 00:14. Заголовок: Perwij 12 bit GSPS..


Perwij 12 bit GSPS 24 mesjaca nazad

http://www.electronicsweekly.com/Articles/28/10/2009/47279/ti-unveils-industrys-first-12bit-1gsamples-adc.htm

TI unveils industry's first 12bit 1Gsample/s ADC
Steve Bush
Wednesday 28 October 2009 14:01
Texas Instruments has unveiled industry's first 12bit 1Gsample/s ADC, the ADS5400. A buffered front-end simplifies external circuit design, and fast sampling means up to four can be used together for 4Gsample/s and 2GHz bandwidth.

"The only devices that come close are also ours, and they sample at 500Msample/s," TI spokesman Heinz-Peter Beckemeyer told Electronics Weekly.

Test and measurement, radar, and signal jamming are the target applications,
-------------------------------------------------------------------------------------------

rather than phones or infrastructure.

The monolithic devices, made on the TI's BiCom3 silicon-on-insulator process, are $775 in 100 unit quantities.

Signal to noise ratio (S/N) is 57dB and "almost flat from DC to 2GHz," said Beckemeyer.

Like its 500Msample/s ADS5463 predecessor, architecturally the 5400 is a pipeline converter.
-------------------------------------------------------------------------------------------------------------
12 bit E2V i National folding interpolating


National posle 23 sent .2011 prinadlezit TI
----------------------------------------------------
"You design the individual stages according to what you optimise: signal to noise, or power," said Beckemeyer. "Our challenge was to keep power in the 2.0-2.5W range. The resulting S/N is 10dB better than anything you will find on the market."

Sampling with a single 5400 at 1GHz means DC to 500MHz coverage. Power is around 2.2W.
------------------------------------------------------------------------------------------------------------

Preceded by bandpass filter, the device can also be used to under-sample, covering 500MHz-1GHz, 1.0-1.5GHz, or 1.5-2.0GHz.

Spurious-free dynamic range (SFDR) is, according to Beckemeyer, 77-78dB at DC, 72-73dB at 1GHz, and in the 60dB range at 2GHz.

Sample-and-hold and analogue bandwidth are sufficient to cover DC-2GHz in one go by running four converters in parallel. On-chip hardware allows two or four devices to be interleaved.
------------------------------------------------

"Generally interleaving will generate spurs in the spectrum.
########################################

This converter has gain, phase and amplitude adjustments to remove the spurs," said Beckemeyer.

These adjustments can also be used for balancing ADCs in an I/Q receiver

Other features include user-selectable single or dual-bus LVDS outputs, allowing a choice between I/O speed and pin-count.

Operation is specified from -40 to 85°C, and the package is a 16x16mm thermally-enhanced,100 pin TQFP.



Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7687
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 03.01.12 18:17. Заголовок: 1.Irbis-E polosa si..


1.Irbis-E polosa signala w rezime SAR 250 mhz ,smotri 1 rolik

razr. sposobnost 1 metr i wische ... eto 250 mhz
http://www.niip.ru/index.php?option=com_content&view=category&layout=blog&id=18&Itemid=23

2. 2500 mhz 100 mm razreschenie

http://www.sandia.gov/RADAR/imageryka.html

kollekzija image ot 35 ghz synthetic apperture radar razr.sposobnost' 4 inches -10 sm,100 millimetr

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.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







Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7701
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 03.01.12 20:55. Заголовок: soobrazenija po razr..


soobrazenija po razrabotke 10 bit 2.2 gsps ADC
( seg .yrowen ot tex ze awtorow 12 bit 1.5 gsps)


http://convergencepromotions.com/atmel/v_6/pdf/v_6_pg-43-48.pdf

http://convergencepromotions.com/atmel/v_6/pdf/v_6_pg-43-48.pdf

For operation at Nyquist (Fin~Fs/2) and above, the
clock phase noise (also called jitter) has direct impact
on SNR. Jitter can be split in 2 components: external jitter
(due to the sources used, or potential board routing
issues), and internal jitter (generated in the ADC by
thermal noise on clock path, coupling with other signals,
or poor power supply rejection). Therefore internal
jitter is also a very important parameter of the ADC.
Parameters to consider for a high speed ADC are therefore:
THD, SFDR, IMD (multitone), SNR, Noise Power
Ratio (for broadband application), ADC added Jitter (for
2nd Nyquist application).


3.2 Quantifier
Quantifier structure choice is a key issue in the design
of an ADC, specially when we are looking simultaneously
for speed, accuracy and power efficiency.
Pipeline and sub-ranging architectures are discarded,
because for this sampling range they are not relevant,
especially regarding B.E.R (Bit Error Rate) issue.
--------------------------------------------------
No
TI 1 gsps ,12 bit ADS5400 - 3 state pipeline
14 bit ,400 msps ADS5474 -pipeline



A full flash architecture is also not acceptable because
of loading effect caused at T/H output due to too many
comparators (210+1), and also because of power
spillage that this architecture would imply.
Finally we retained a successively folded and interpolated
architecture which offers the best trade-off
between speed, accuracy and power dissipation.
The MSBs are generated by a coarse cycle pointer, and
are corrected in accordance with LSB’s transition in the
logic part. Gain adjustment is made by controlling the
bias of the reference resistor chain.

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7702
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 03.01.12 21:20. Заголовок: 3 GS/s S-Band 10 Bit..


3 GS/s S-Band 10 Bit ADC and 12 Bit DAC on SiGeC Technology

http://see.conference-services.net/resources/253/1452/pdf/RADAR2009_0293.pdf


D. ADC Characterization Results
1) ADC Single Tone FFT Computation at 3 GS/s in 1st, 2nd
and 3rd Nyquist zones
At 3 GS/s in the 1st Nyquist (Fin=1495MHz, -1dBFS), an
ENOB of 8.1 Bit and an SFDR of 59 dBc is achieved (Fig. 3).
In the 2nd Nyquist (Fin=2995MHz, -3 dBFS), an ENOB of 8.0
Bit is still achieved, with an SFDR performance of 58 dBc
(Fig. 4). With Fin=3995MHz (-3 dBFS), corresponding to the
S_Band upper limit, the ENOB is still 7.7 Bit, with an SFDR
of 55 dBc, and the SNR is 49.5 dBFS. The SNR roll off versus
input frequency is related to the voltage noise induced by the
120 fs rms internal sampling clock jitter of the ADC. The
large linearity roll off over frequency is related to the large
signal dynamics of the front-end Track and Hold, which
improves for smaller signals.
The 0dBFS ADC Full Scale reference voltage span is 500 mV,
and Full Scale input power is -2dBm if single-ended driven in
50 Щ and -5 dBm if differentially driven in 100 Щ termination.
At 3 GS/s and Fin = 3 GHz, an SNR of 51 dB is achieved,
leading to an FFT noise floor of: SNR + 10log(N/2) =
51dB+10log(16384)=93dB per 32K FFT bin width.
The normalized noise floor in dBc/Hz at Fs=3 GS/s is 51 dB +
10log(Fs/2)=142.7dBc/Hz. Since ADC Full Scale differential
input power is -5dBm, the normalized (per/Herz) Noise floor
is -5dBm-143dB = -148 dBm/Herz. The ADC total noise
power includes the input referred thermal noise and the
voltage noise induced by time jitter. Therefore the contribution
of the ADC to overall system noise figure can be calculated.

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7703
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 03.01.12 21:47. Заголовок: http://www.triquint...

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7705
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 03.01.12 23:46. Заголовок: Software Defined Mul..


Software Defined Multi-Channel Radar Receivers for X-band Radars
Missile Defense Agency - STTR FY2009B - Topic MDA09-T003
Opens: August 24, 2009 - Closes: September 23, 2009
--------------------------------------------------------------------------------


MDA09-T003 TITLE: Software Defined Multi-Channel Radar Receivers for X-band Radars

TECHNOLOGY AREAS: Sensors, Electronics

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), which controls the export and import of defense-related material and services. Offerors must disclose any proposed use of foreign nationals, their country of origin, and what tasks each would accomplish in the statement of work in accordance with section 3.5.b.(7) of the solicitation.

OBJECTIVE: Investigate and develop Software-Defined Multi-channel Receivers to enhance X-Band radar systems performance.

DESCRIPTION: Future X-Band radar systems will employ low-cost antenna array technology and digital beamforming architecture that requires multiple receiver channels. Demonstrating the utility of software defined, scalable multi-channel receiver technology that reduces cost, weight, and size while enhancing radar system flexibility and performance is the optimal goal of this research. With recent development of the state-of-the-art receiver technology coupled with high-speed computing devices, multi-channel receiver (consisting of up to 100s of channels) controlled by software may possible. The advantage of software defined multi-channel receiver is that the reconfiguration of hardware components can be done relatively quickly. The benefit of employing software defined receiver is that the implementation would rely heavily on the digital signal processing algorithm and requiring fewer hardware components. Subsequent benefits such as improvement in dynamic range, quadrature coherency, reliability, and low cost. The primary objective of this research is to investigate the feasibility of software-defined technology that offers the potential of a low-cost robust multi-channel receiver solution. The multi-channel receive takes X-Band RF signals and outputs digitized In-phase and Quadrature (I&Q) data. The receiver should cover a 25-40% operating bandwidth centered at X-Band. The receiver should cover a tunable instantaneous bandwidth of 1GHz (goal), 400MHz (threshold), with an instantaneous dynamic range of 52+ dB. The control interfaces should utilize Open System Architecture to the maximum extend possible for ease of integration within the radar systems.

PHASE I: Investigate the feasibility, technical issues, and risks of developing software-defined multi-channel receiver at X-Band. Conduct computer modeling and demonstrate proof of concept implementation. The research will result in a detail report on how the software defined multi-channel receiver would be built to meet the performance while attaining the low cost and small size objective.

PHASE II: Demonstrate the operation of the developed prototype software defined multi-channel receiver using low-cost components. Validate performance, cost and reliability benefits to be achieved through a prototype device. Quatify the benefits of digital signal processing implemention and approach and identify commercial radar application opportunity.

PHASE III: Design and validate the software defined multi-channel receiver prototype developed in Phase II for X-Band radar systems for military and commercial applications. Work closely with missile defense agency (MDA) to target potential technology insertion and integration into MDA ballistic missile defense systems.

COMMERCIALIZATION: The proposed technology has a number of related commercial applications in radio frequency (RF) sensors. Commercial radar systems, commercial RF communications systems that require software defined multi-channel receiver.

REFERENCES:
1. J. H. Reed, "Software Radio A Modern Approach to Radio Engineering", Prentice Hall Communications Engineering and Emerging Technologies Series, 2002.

2. R. Seal, J. Urbina, M. Sulzer, S. Gonzalez, N. Aponte, "Design of an FPGA-based radar controller", National Radio Science Meeting, Boulder, CO, Jan 2008.

3. J. Mitola, "Cognitive radio: an integrated agent architecture for software defined radio", Ph.D. dissertation, KTH Royal Institute of Technology, Stockholm, Sweden, 2000.

4. T. Quach et al, "X-Band Receiver Front-End Chip in Silicon Germanium Technology", IEEE 8th Topical Meeting on Silicon for RF Systems, Jan 2008.

5. R. Dragenmeister et al, "Multi-Chip-Module Based X-Band Receiver Utilizing Silicon Germanium MMICs", GOMACTECH 2008, Mar. 2008.

KEYWORDS: Antenna Array, Multi-channel Receiver, Analog to digital converter, Radar receiver, Digital Beamforming, phased array radar.

TPOC: Dr. Seng Hong
Phone: 937.255.3802 X3449
Fax: 703.882.6350
Email: seng.hong@wpafb.af.mil



Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7712
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 04.01.12 00:25. Заголовок: For example, look at..


For
example, look at US PCS of 5 MHz. If the lowest frequency
were translated to 1 MHz, the highest frequency of the band
would be at 6 MHz. However, if a carrier were operational at
the bottom of the band (1 MHz IF frequency), the second and
third harmonic would fall at 2 and 3 MHz respectively, right in
the middle of the band. These harmonics definitely can disrupt
calls in a wide dynamic such as GSM or AMPS.
Now consider the case where the bottom frequency of the band
was translated to 5.1 MHz instead of 1 MHz. The upper
frequency would align with 10.1 MHz. Now a quick look at the
harmonics shows that the second harmonic of 5.1 MHz would
fall at 10.2 MHz, outside the band of interest. The higher the
IF frequency, the more spread out the harmonics and signals of
interest become. In a practical sense, the IF frequency should
be as high as the ADC could reasonably process.

http://www.analog.com/static/imported-files/tech_articles/371982266wideband.pdf

t.e. 260-510 mhz IF/Pch dlaj 250 mhz polosi Irbis-E

510-1010 mhz dlja 500 mhz polosi NIIP AFAR

Спасибо: 0 
Профиль
milstar
moderator




Сообщение: 7714
Зарегистрирован: 09.02.08
Репутация: 0
ссылка на сообщение  Отправлено: 04.01.12 01:09. Заголовок: ALCOR C-Band ,500 mg..


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
----------------------------------------------------------------------------------------------------------------
Tolko 12- bitnie AZP .. .. eto znachit chto SNR wsego 56-57 db
A SFDR 65-66 dbfs


T.e. na 23-25 db xuze chem y 16 -bitnix

Спасибо: 0 
Профиль
Ответов - 301 , стр: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 All [только новые]
Тему читают:
- участник сейчас на форуме
- участник вне форума
Все даты в формате GMT  3 час. Хитов сегодня: 14
Права: смайлы да, картинки да, шрифты нет, голосования нет
аватары да, автозамена ссылок вкл, премодерация откл, правка нет



Перспективная зенитная ракетная система противовоздушной и противоракетной обороны ЗРС С-400 "Триумф"