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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
milstar: http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA391707 NRL
milstar: CONCLUSIONS The performance realized with the experimental Stacked ADC described in this report has demonstrated the feasibility of increasing the effective dynamic range in a practical radar signal processor from 60 to 65 dB to 78 to 83 dB while maintaining a SINAD of 45 to 50 dB against a two-tone input signal.
milstar: http://www.flex-radio.com/FLEX-6000.pdf
milstar: The Advance e710 board weighs just under 150grams yet delivers 75GFLOPS/s (dgemm performance) or 18GFLOPS/s (FFT performance), so it is easy to see why the CSX700 is an ideal platform for high performance processing applications that require small size, weight and power footprints http://www.clearspeed.com/products/csx700embedded.php
milstar: Synthetic Aperture Radar - SAR -------------------------------------------------------------------------------- We excel in processing Radar data sets, from front end capture and pulse compression techniques to SAR processing and beyond. The ClearSpeed processor platform efficiently computes single precision complex FFTs (see our CSX700 FFT benchmarks). By being software programmable the developer can instruct the processor to perform additional operations while the data is distributed across the processing array. http://www.clearspeed.com/applications/syntheticapertureradar/index.php http://www.clearspeed.com/applications/digitalsignalprocessing/csx700fftperformance.php
milstar: 2/4-Channel 250MSPS 16-bit PCIe A/D Board Achieves > 160dB Dynamic Range with on-board Hardware Averaging ######################################## http://www.ultraviewcorp.com/displaynews.php?news_id=9
milstar: http://www.analog.com/static/imported-files/circuit_notes/CN0268.pdf
milstar: http://www.embedded.com/design/analog/4373038/2/Product-How-To--Passive-filter-options-achieve-very-high-SNR--SFDR-in-a-low-power-16-bit-ADC-interface--Part-1-
milstar: http://www.youtube.com/watch?v=0JFU4oFmAdE
milstar: http://www.youtube.com/watch?v=0JFU4oFmAdE
milstar: http://electronicdesign.com/analog/dither-can-boost-sampled-data-system-performance-least-10-db
milstar: - В России уже несколько лет реализуются меры по развитию отечественной электронной компонентной базы. Как ваш концерн участвует в этой работе? - Абсолютно точно понятно, что это серьезная, национальная проблема. В сфере микроэлектроники мы ввели в Зеленограде линию по производству микросхем технологии сначала 180 нанометров, потом 90 нанометров, решаем вопрос о переходе на 65 нанометров - это серьезный шаг вперед. Когда мы говорим об использовании импортной электронно-компонентной базы в наших изделиях, то приходится признать, что она имеется в наших изделиях. Иногда их доля значительно выше 50 процентов. Например, в космической отрасли она зашкаливает за 90 процентов. Хотя, как вы понимаете, для той области, которой мы занимаемся, для оборонной отрасли и военного космоса это архиважная задача. Очень большие средства тратятся и много сил отвлекается на проверку зарубежной электронной компонентной базы. Особенно класса space и military. - То есть вы не согласны с теми, кто говорит, что чипы можно купить и за рубежом, никакой беды в этом нет? - Это абсолютно не правильно. Конечно, мы вынуждены будем покупать микросхемы за рубежом, но при этом надо помнить, что наличие собственной микроэлектроники - это вопрос обеспечения национальной безопасности. Это связано напрямую с возрастающей ролью информационных технологий и необходимостью обеспечения кибербезопасности во всех сферах жизни общества. Генеральный директор ОАО "РТИ" Сергей Боев: http://www.militarynews.ru/excl.asp?ex=152
milstar: TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words) Ridgetop Group will develop a 3X improvement in sampling resolution over current state-of-the art analog-to-digital converter (ADC) technology to support reconfigurable/reprogrammable communication systems. The significance of this innovation lies in the time-interleaved pipeline ADC, based on the most advanced silicon-germanium (SiGe) BiCMOS technology available, with over 2 bits higher effective number of bits (ENOB = 11.0 bits) than the best commercially available radiation-tolerant 2 GS/s ADCs (ENOB = 8.9 bits). In addition, the ADC consumes 65% less power than commercial ADCs, conserving valuable spacecraft power. For maximum flexibility and minimal power consumption, the ADC provides two configurable pipeline channels and four programmable operation modes. The ADC will also provide 3 GHz input analog bandwidth for direct sampling of RF signals in the S-band. The ADC will tolerate 5 Mrads of total ionizing dose (TID) radiation due to the inherent radiation tolerance of the SiGe heterojunction bipolar transistors (HBT), 130 nm thin-oxide CMOS transistors, and standard radiation-hardening-by-design (RHBD) techniques. The ADC will be also sufficiently hardened against single-event effects (SEE). Ridgetop will fabricate and test the ADC in the IBM 130 nm BiCMOS SiGe process in Phase 2 of this SBIR program. http://sbir.gsfc.nasa.gov/SBIR/abstracts/11/sbir/phase1/SBIR-11-1-O1.02-9553.html
milstar: http://www.analog.com/static/imported-files/circuit_notes/CN0227.pdf The overall circuit has a bandwidth of 152 MHz with a pass band flatness of 1 dB. The SNR and SFDR measured with a 120 MHz analog input are 72.6 dBFS and 82.2 dBc, respectively.
milstar: The ADC input bandwidth and distortion performance must be adequate at the IF frequency, rather than only baseband. This presents a problem for most ADCs designed to only process signals in the first Nyquist zone—an ADC suitable for undersampling applications must maintain dynamic performance into the higher order Nyquist zones. http://www.analog.com/static/imported-files/tutorials/MT-002.pdf Sampling signals above the first Nyquist zone has become popular in communications, because the process is equivalent to analog demodulation. It is becoming common practice to sample IF signals directly and then use digital techniques to process the signal, thereby eliminating the need for an IF demodulator and filters.
milstar: igure 3: Quantization Noise Spectrum Showing Process Gain The significance of process gain can be seen from the following example. In many digital basestations or other wideband receivers the signal bandwidth is composed of many individual channels, and a single ADC is used to digitize the entire bandwidth. For instance, the analog cellular radio system (AMPS) in the U.S. consists of 416 30-kHz wide channels, occupying a bandwidth of approximately 12.5 MHz. Assume a 65-MSPS sampling frequency, and that digital filtering is used to separate the individual 30-kHz channels. The process gain due to oversampling for these conditions is given by: Process Gain =10log10 fs =10log10 65×106 2⋅BW 2×30×103 = 30.3dB. Eq. 11 The process gain is added to the ADC SNR specification to yield the SNR in the 30-kHz bandwidth. In the above example, if the ADC SNR specification is 65 dB (dc to fs/2), then it is increased to 95.3 dB in the 30-kHz channel bandwidth (after appropriate digital filtering).
milstar: SNR, PROCESS GAIN, AND FFT NOISE FLOOR RELATIONSHIPS Figure 6 shows the FFT output for an ideal 12-bit ADC. Note that the average value of the noise floor of the FFT is approximately 107 dB below full-scale, but the theoretical SNR of a 12-bit ADC is 74 dB. The FFT noise floor is not the SNR of the ADC, because the FFT acts like an analog spectrum analyzer with a bandwidth of fs/M, where M is the number of points in the FFT. The theoretical FFT noise floor is therefore 10log10(M/2) dB below the quantization noise floor due to the processing gain of the FFT. In the case of an ideal 12-bit ADC with an SNR of 74 dB, a 4096-point FFT would result in a processing gain of 10log10(4096/2) = 33 dB, thereby resulting in an overall FFT noise floor of 74 + 33 = 107 dBc. In fact, the FFT noise floor can be reduced even further by going to larger and larger FFTs; just as an analog spectrum analyzer's noise floor can be reduced by narrowing the bandwidth
milstar: Practical Examples A high-speed 12-bit converter developed by e2v, the EV12AS200, comprises a single-core 1.5-Gsample/s ADC with 2.3-GHz bandwidth.3 It’s based on a 200-GHz silicon-germanium-carbon (SiGeC) bipolar technology. In L-Band radar applications, the device enables direct digitizion of 500-MHz broadband arbitrary waveforms in the second Nyquist region closer to the antenna—a key factor when designing flexible, simplified radar receiver systems. Adding dither to the EV12AS200’s input signal will enhance performance. This was demonstrated in a test using a filtered noise diode as the dither source input to one side of the ADC’s differential input (Fig. 3). http://electronicdesign.com/analog/dither-can-boost-sampled-data-system-performance-least-10-db
milstar: http://www.eetimes.com/design/microwave-rf-design/4370321/Selecting-high-speed-ADCs-for-high-frequency-applications?pageNumber=1
milstar: Сверхбыстродействующие АЦП и ЦАП компании E2V http://www.symmetron.ru/suppliers/e2v/dac.shtml
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