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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: AD9467 16 bit 250 msps SiGe 0.18 micron EV12AD550 12 bit 1.6 gsps BiCMOS 0.13 micron AD9213 12 bit 10.25 GSPS CMOS 0.022 micron 3600 $
milstar: https://www.analog.com/media/cn/training-seminars/design-handbooks/3689418379346Section5.pdf
milstar: http://www.ti.com/lit/an/slaa594a/slaa594a.pdf We will use the example of a 70-MHz signal with 20-MHz bandwidth (60 MHz to 80 MHz) for the discussion throughout this paper. For a radar application and for communication systems, generally 70 MHz is used as IF (intermediate frequency) with a specific bandwidth ranging from a few KHz to a few MHz. The maximum frequency component is 80 MHz in this signal. For an oversampling case, the minimum sampling rate is more than 160 MSPS. To keep this band of 60 MHz to 80 MHz in the middle of the first Nyquist Zone, the sampling frequency is 280 MSPS. This signal in frequency domain is shown in Figure 1 ===================== Some of the radio designs use the one down converter stage for converting the 70-MHz IF signal to a lower IF frequency, say 14 MHz 4 -24 mhz с точки зрения максимального динамического диапазона правильное решение ,конечно зависит от динамического ранга смесителя SFDR ADC падает с частотой ============ 3.1 processing gain LTC 2107 210 msps Fin 30 mhz SFDR 96.8 dbFS Fin 71 mhz SFDR 87 dbFS Fin 14mhz +-10mhz 4-24 mhz SFDR 96.8 mhz SNR Fin 30 mhz 79.7 dbFS + process gain (210/2) /20 mhz = 7 db ...=87 dbFS
milstar: While multiple IF stages can become a source of distortion products and spurious responses, the IC-7700 utilizes Icom’s original image-rejection mixers in a simple double conversion superheterodyne. This reduces distortion and produces a much cleaner audio signal compared to triple or quadruple superheterodyne receivers. https://www.icomamerica.com/en/products/amateur/hf/7700/default.aspx
milstar: https://www.icomamerica.com/en/products/amateur/receivers/r8600/Icom-R8600-QST-product-Review.pdf
milstar: http://www.sherweng.com/table.html Yaesu FT-DX101D 18 bit ADC 15msps 9mhz if 4000$ 10 khz -50mhz Flex6700 pure SDR 250 msps 16 bit ADC 6000 $ 10 khz-50 mhz ICOM RC8600 triple conversion superhet + 14 bit ADC 130 msps in demodulator 10 khz-3 GHZ(!) 2000$-2300$
milstar: Highest performance with a bandwidth appropriate filter right up front after the first mixer. This keeps the undesired strong signals from progressing down stream to the next stages. http://www.sherweng.com/ctu2012/NC0B-CU-2012-6a.pdf
milstar: n addition to the classic communica - tions receiver and spectrum analyzer that monitors specific channels or bands, the R8600 is also a “scanner” radio, where the emphasis is on rapid scanning across wide bandwidths, searching for signals of interest that may have unknown frequencies. https://www.icomamerica.com/en/products/amateur/receivers/r8600/Icom-R8600-QST-product-Review.pdf
milstar: https://docs.wixstatic.com/ugd/af543b_4d316147bdf44a73b1d05974fe0ce01a.pdf
milstar: https://mri-progress.ru/products/all-lists/K5111HB015.pdf russian 200 msps 16 bit
milstar: http://www.ti.com/lit/ds/symlink/ads5485.pdf K5111HB015 analog ads5485 https://mri-progress.ru/products/all-lists/K5111HB015.pdf
milstar: ads5485 https://www.pentek.com/pipeline/23_1/PIPE231.pdf
milstar: https://www.analog.com/en/products/ad9697.html# 14 bit ,1.3 GSPS SFDR 81 dbfs SINAD 62.3 dbfs by 1.36 volt p-p ,1980 mhz 415 $
milstar: AD9467 16 bit 250msps -119$ LTC2107 16 bit 210 msps 99$ 30-70 mhz sfdr 100 db AD9690 14 bit 1 gsps 292$ 985 mhz sfdr 80 db AD9695 14 bit 625 msps 406$ 1000 mhz 1.3 v p-p 85 db 1300 msps 831$ 1980 mhz 1.3 v p0p 81 db AD9697 14 bit 1300 msps 415$ 1980 81 db
milstar: https://www.flexradio.com/flex-6700/ Wideband Frequency Coverage: 30 kHz – 72 MHz; 135 – 165 MHz Receiver Architecture: Direct Digital Sampling ADC Resolution: 16-bits ADC Sampling Rate: 245.76 Msps Spurious and Image Rejection Ratio: 100 dB or better https://www.flexradio.com/documentation-flex6000series/ Flex 6700 QST review https://www.flexradio.com/downloads/flex-6700-flex-6300-review-qst/
milstar: 3.1 Processing Gain When the signal is oversampled a greater number of times than its signal bandwidth, then the processing gain is achieved in addition to the SNR shown in the ADC datasheets. For example, for the ADS4149, at 70 MHz, the SNR will be around 72 dB at the sampling rate of 200 MSPS. For our example of 70 MHz with 20-MHz bandwidth, the signal is oversampled by 10 times with respect to signal bandwidth. Note that with respect to the signal frequency of 70 MHz, it is oversampled only around 3 times. Due to oversampling of 10 times to the bandwidth, system designers get the extra advantage of processing gain in addition to the actual SNR mentioned in the datasheet. For Fs of 200 MSPS, the SNR of 72 dB is for a Nyquist bandwidth of Fs/2, that is, 100 MHz. For the measurement of SNR of the ADC, the noise in the entire band of 100 MHz is considered in this case. The processing gain is achieved by using the following formula: Process Gain = 10 log ((Fs/2)/BW) Where Fs is the sampling Rate; BW is the signal bandwidth; For the oversampling example, BW is 20 MHz, Fs is 200 MHz. If we use the above formula, the processing gain is around 7dB. The total SNR can be calculated using the following formula: SNRtotal = SNRds + Process Gain Where SNRtotal is the total SNR after adding the processing gain and SNRds is the SNR value provided in the datasheet (without the processing gain). SNRtotal is 79 dBFS (72 + 7) using the above formula. 6 3.2 Frequency Plan Flexibility With oversampling, the advantage is the frequency plan. System designers can select the IF frequency location wherever required in the first Nyquist Zone based on the availability of passive filter modules at that frequency and for optimizing selection of ADC front end circuit design in that frequency band. The IF frequencies can always be moved anywhere from DC to Fs/2 frequency, with an eye on keeping the flexibility on the filter design. The second and third harmonics of the 70-MHz IF falls out of the first Nyquist Zone and can be easily filtered in the oversampling case of 200 MSPS sampling rate. Whereas, in the undersampling case, the system designers must plan the filter design in such a way that the HD2 and HD3 impacts are minimal. The ADC input filter design has to take care of this distortion issue in the undersampling case. 3.3 Handling Higher Signal Bandwidths The another inherent advantage of oversampling is the capability of handling higher-signal bandwidths. For the oversampling case of 200 MSPS, the ADC can handle around 100-MHz signal BW. This BW is called Nyquist BW. But as per our example case, the signal BW is only 20 MHz and hence the sampling rate of 56 MSPS will be good enough. For the TI ADC12D1600 ADC, the Nyquist BW is 1600 MHz with a sampling rate of 3200 MSPS. This type ADC is generally used for handling very high signal BWs for radio applications. Designers must make the right sampling rate choice for their specific design. The key thing to remember is keeping the entire signal BW inside a single Nyquist Zone for avoiding the bad aliasing effects and keeping the signal BW in the middle of any particular Nyquist Zone for flexibility in the filter design.
milstar: Since a direct sampling technique folds the signal energy from each zone back into the first Nyquist, there is no way to accurately discriminate the source of the content. As a result, rogue energy can appear in the first Nyquist zone, which will degrade signal-to-noise ratio (SNR) and spurious free dynamic range (SFDR). Spectral issues can potentially plague government and military applications, both for sensing and communications. http://mil-embedded.com/articles/bandwidth-king-aerospace-defense-applications/
milstar: Future ADCs specifically designed for undersampling applications will incorporate the previously discussed techniques in a single-chip designs. These ADCs will be characterized by their wide SFDR at input frequencies extending well above the Nyquist limit, fs /2. The basic architecture of the digital IF receiver is shown in Figure 5.31. The addition of a low-distortion PGA under DSP control increases the dynamic range of the system. IF frequencies associated with 900MHz digital cellular base stations are typically around 70MHz with bandwidths between 5 and 10MHz. SFDR requirements are between 70 and 80dBc. On the other hand, 1.8GHZ digital receivers typically have IF frequencies between 200 and 240MHz with bandwidths of 1MHz. SFDR requirements are typically 50dBc. http://sss-mag.com/pdf/ad5.pdf
milstar: https://www.analog.com/media/en/training-seminars/tutorials/MT-002.pdf
milstar: https://www.analog.com/media/en/training-seminars/design-handbooks/High-Speed-Design-Techniques/Section5.pdf
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