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] ###########################
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
ADVANCED SCIENCE & NOVEL TECHNOLOGY 27 Via Porto Grande Rancho Palos Verdes, CA 90275 Phone: PI: Topic#: (408) 564-9236 Dr. Sean P. Woyciehowsky MDA 07-003 Awarded: 02/13/08 Title: High Performance Rad Hard Analog to Digital Converter Architectures Abstract: Electronic components for future space based radar systems on chip (SOC) must function correctly in natural and radiation filled environments while providing state-of-the-art performance. The corresponding SOC must employ advanced, extra low-power, radiation-hardened (RH), analog-to-digital converters (ADCs) capable of operating at multi-giga sampling speeds. To satisfy the described needs, we propose to develop an ADC block with 9 bits of resolution and up to 10Gs/s of sampling speed. The 9 bit wide data will be demultiplexed by a factor of eight to a rate of 1.25Gb/s for direct loading into a following FPGA where signal processing will be performed. Our patent-pending radiation-hardening techniques incorporate a methodology based on protection and redundancy, which provides both total ionization dose (TID) and single-event upset (SEU) tolerance within the IC. The proposed high performance characteristics of the ADC will be achieved by utilizing an advanced SiGe IC fabrication technology. -----------------------------------------------------------------------------
HITTITE MICROWAVE CORP. 20 Alpha Road Chelmsford, MA 01824 Phone: PI: Topic#: (719) 590-1112 Dr. Michael Hoskins MDA 07-003 Awarded: 02/13/08 Title: High Sample-Rate Ultra-Wideband Track-and-Hold Demultiplexer (2007047) Abstract: Hittite proposes to develop a Radiation-Tolerant Ultra-Wideband Track-and-Hold (T/H) Demultiplexer to address MDA's future needs for microwave signal sampling/data conversion. This development is motivated by the difficulties in achieving high-speed interleaved analog-to-digital converter (ADC) assemblies with good accuracy. -----------------------------------------------------------------------------------------------------------------
A switched-emitter-follower T/H amplifier in the SiGe BiCMOS process with the capability for 15 GHz sampling bandwidth, 6 - 8 Gs/s sample rate, and 8 - 9 bit accuracy will be studied. This high-speed T/H will be used as the front end of a ------------------------------------------------------------------------------------ two-rank T/H sampler/demultiplexer that provides a 2:1 output sample rate reduction, enabling the use of lower rate ADCs in an interleaved assembly without the usual sample timing mismatches that degrade performance. ----------------------------------------------------------------------------------------------------------------------
The T/H demultiplexer can also operate as a subsampler to down convert any Nyquist bands within the 15 GHz bandwidth. This T/H circuit is expected to offer unprecedented bandwidth and operating speed while maintaining accuracy suitable for meeting the X-band and microwave data conversion goals of many military systems. Under Phase I, Hittite will perform a design study with circuit simulations to determine the feasibility and performance of the basic T/H amplifier and the two-rank demultiplexer. Prototype circuits will be built and tested in Phase II.
NU-TREK 17150 Via del CampoSuite 202 San Diego, CA 92127 Phone: PI: Topic#: (909) 864-7858 Mr. William Poland MDA 07-003 Awarded: 02/13/08 Title: Multiplexed, Rad Hard ADC Abstract: The proposed part is a rad-hard, 16-input, 14-bit ADC, with aggregate speed of 200 MSPS. -------------------------------------------------------------------------------------------------------------------- dlj srawnenija 09.2010 National 12 bit 1000 msps ,100 krad
The 16 inputs are sampled individually and can be configured as 16 single-ended inputs or 8 differential inputs. The ADC provides 14 data outputs, a data-ready signal, and an over-range indicator. The digital outputs of the ADC are CMOS low-voltage differential signal (LVDS) outputs. The part will be fabricated using Texas Instruments' BiCom3X, a SOI process with CMOS and complementary SiGe bipolar transistors. SiGe bipolar transistors typically have very high total dose hardness, ------------------------------------------------------------------------------------------------------------------------------------------
and we are not aware of an ELDRS problem. The SOI wells prevent latch-up and restrict the silicon volume that can produce photocurrents from either ionizing dose rates or single event strikes. Our designers, Bill Poland, Jim Swonger, Wayne Dietrich and John Branning, have designed over 140 ASICs, many of them rad-hard. They worked together on a 14-bit rad-hard ADC, on which the proposed part is based. Nu-Trek is an emerging suppler of rad-hard parts, with four parts coming on sale in 2008. The Nu-Det has already been inserted into the MKV and NGIMU. The Clam/NED is slated for insertion in the Army's FCS.
Отправлено: 22.10.10 22:13. Заголовок: However, as discusse..
However, as discussed in the article entitled “A Wide Dynamic Range Radar Digitizer,” [1] converting to the digital domain introduces errors which limit overall system performance.
One of the most important limitations is dynamic range, which is the range of signal amplitudes that can be captured by an ADC. This is determined by the number of conversion bits as well as by the signal-to-noise ratio (SNR) of the analog components (amplifiers, mixers, etc.) which precede the ADC.
Отправлено: 25.10.10 12:05. Заголовок: For example, in mili..
For example, in military radar systems, a single ADC12D1X00 combined with a digital down-converter can replace multiple mixers, filters, amplifiers and local oscillator stages used in traditional heterodyne double- or triple-conversion radio implementations. #####################
Since this new class of SDRs requires the ADC to sample wide-bandwidth signals, a new set of metrics such as noise-floor, NPR and IMD provide the best measure of a system's capability to extract narrowband information from a wideband spectrum.
This is in stark contrast to traditional ADC specifications -- signal-to-noise ratio (SNR), spurious-free dynamic range (SFDR), and effective number of bits (ENOB) -- which focus on single-tone performance in the Nyquist bandwidth and do not provide the best gauge of a system's overall capability.
...and IMD ###########
Dlja ADC!2D1800
DESIQ mode -61 db
1212 mgz ,1217 mgz -54 db
chut lutsche chem SINAD na 1448 mgz -50db ------------------------------------------------------
Отправлено: 25.10.10 12:41. Заголовок: Menee skorostnoj 12..
Menee skorostnoj 12D1000 non des -mode ,1000 megasample -sootw .mozet obrabotat 500 mgz polosu signala protiv 12D1600 non des mode - 800 mgz , 12D1800 non des mode ,1800 megasample ,900 mgz
ENOB 8.6 db 8.6 db 8.4 db 1448 mgz SINAD 53.6 db 53.8 db 52.5 db SNR 54.1 db 55 db 53.1 db SFDR 67 db 61.9 db 60.3 db
Analog–to–Digital Converter Technology and Corresponding Signal Processor Throughput and Dynamic Range. For the PATRIOT radar, advanced signal process technology is required to support dynamic ranges while maintaining the throughput, size, weight, and prime power requirements. Applicable advanced signal processing techniques, such as maximum entropy method (MEM), are required for incorporation into PATRIOT, along with a concept for their utilization, signal processor hardware concepts, and an assessment of their performance improvement over pulse Doppler for various environments.
The PAC–3 radar signal processors currently use 12–bit A/D converters for narrow band actions. For radar performance in clutter, more dynamic range is needed—up to 14–16 bits for wide band. system/transmitter intermediate frequency (S/T–IF) receiver subsystem changes would require the incorporation of 16 bit A/D converters into the PATRIOT S/T–IF receive subsystem, along with the incorporation of the advanced signal processor hardware and processor resident software. Included in the proposed architecture and design is the removal or disabling of the current digital signal processor and the replacement of their functions in the advanced signal processor. The CDI–3 receiver subsystem was designed for later incorporation of 12 bit A/D converters when available. The incorporation of the 14–bit converter will require some redesign of the receiver. The value added for PATRIOT is improved fire unit search, track, and CDI capabilities in low altitude, high clutter or extensive antitactical missile debris environments. The technology infusion period is from 1QFY02 to 4QFY03. [POC: Rodney Sams, PATRIOT, (205) 955–3166]
Отправлено: 25.10.10 15:21. Заголовок: Hall: We did engage ..
Hall: We did engage with one company by the name of Mercury Computer Systems. -----------------------------------------------------------------------------------------------
postawschik Northrop
They build data acquisition cards and essentially the company's creates data acquisition card solutions. The company is focused on military/aerospace applications. What results is a proof of concept through these data acquisition cards and then the company will typically do a custom job for a particular project.
Brian Kimball, Principal HW Engineer at Mercury Computer Systems told us: “We needed a 16-bit, 250-MSPS data converter with 90 db of SFDR for one of our key customer's highly advanced, data acquisition systems. The AD9467 data converter was designed into this customer's system because it met our SFDR, ENOB, and power requirements. Analog Devices worked with us as trusted advisors to provide early-access silicon and design support to enable the timely development of our prototype product.”
What caught MCS' customer's attention was their system's performance based on our ADC. We've been working with Mercury for a couple of quarters now in terms of early engagement and early samples for them. It has been very successful for them.
Tekmicro Supplies Signal Processing System for NASA Glenn Research Center
New Texas Instruments ADS5400 Supports Tekmicro’s Unprecedented Performance ######################################################
on stoit 775 $ w partijax po 100 stuk ,12 bit 1000 megasamles --------------------------------------------------------------------------
Chelmsford, MA – October 26, 2009 – TEK Microsystems, Inc. announced it has shipped follow up system orders to NASA Glenn Research Center in Cleveland, OH. Glenn is developing
a VXS-based satellite communications test set for ground based validation of satellite equipment. The test set will be used ################################################################ for the Tracking and Data Relay Satellite System compatibility testing as part of NASA’s Constellation Program. Successful development will result in additional orders of totaling over $1M.
NASA’s Constellation Program is building the next generation of space vehicles that will take astronauts to low Earth orbit, the moon, and eventually to Mars.
Tekmicro’s Titan-V5 VXS and Callisto VXS boards are now being used in the program. Titan-V5 VXS was selected because of its first-in-the-industry levels of high performance, low latency, and signal integrity.
The Titan-V5 combines four channels of 1 GSPS 12-bit ADCs, four channels of 1.2 GSPS 14-bit DACs and three Virtex-5 FPGAs to provide the highest bandwidth channel count per slot available for VXS products on the market today.
By providing a massive FPGA processing resource at the heart of the VXS communications fabric, Callisto achieves an optimal balance between processing power and IO bandwidth; maximizing the value that can be extracted from the use of FPGAs for signal processing.
“The Titan-V5 utilizes best-in-class devices for digitization and signal generation, and, it redefines low latency by providing almost instantaneous acquisition-to-response times when compared with older architectures using multiple boards or modules,” comments Andy Reddig, CEO/CTO of Tekmicro. “Our ability to implement the newly announced ADS5400 from Texas Instruments gave our engineering team technology with nearly 2x the speed of competitive offerings. The culmination of these advanced technologies gives Titan-V5 a competitive edge for signal processing solutions.”
In addition to Callisto and Titan-V5, Tekmicro offers the broadest range of Xilinx Virtex-5 based streaming I/O and FPGA processing solutions for both analog and digital I/O in the industry today in both commercial and rugged options.
About TEK Microsystems, Incorporated Founded in 1981 and headquartered in Chelmsford, Massachusetts, Tekmicro designs, manufactures and delivers a wide range of advanced high-performance boards and systems for embedded real-time data acquisition, data conversion, storage and recording. Tekmicro provides both commercial and rugged grade products that are used in real-time systems designed for a wide range of defense, intelligence and industrial applications such as C4ISR, SIGINT, EW and Radar.
Tarvos-V5 Overview Designed to meet the needs of demanding sensor-processing applications across a range of environments, the Tarvos-V5 employs three Xilinx Virtex®-5 FPGAs, advanced DDR3 SDRAM, and the highest resolution digital-to-analog and analog-to-digital converter technologies available at a 185 Msps sampling rate.
Each analog input channel uses a Linear Technology LTC2209 16-bit A/D converter, which is designed for digitizing high frequency, wide dynamic range signals within an analogue input bandwidth of 700 MHz. A range of options are available for input signal conditioning to support different receiver applications.
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