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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: The superior performance of this mixer is ideally suited for a wide range of mission-critical, high performance applications that are exposed to strong interference sources such as multi-carrier GSM, 4G LTE and LTE-Advanced multimode basestations, point-to-point backhauls, military communications, wireless repeaters, public safety radios, VHF/UHF/white-space broadcast receivers, radar and avionics. The LTC5551 offers very high linearity of +36dBm IIP3, (input third-order intercept), and low 9.7dB noise figure comparable to the highest IIP3 passive mixers available. Unlike passive mixers which typically have 7dB to 9dB of conversion loss, the LTC5551 boasts 2.4dB of conversion gain, substantially improving receiver dynamic range. The device also has broad RF frequency range capability, operating from 300MHz to 3.5GHz. https://www.powersystemsdesign.com/articles/linears-36dbm-iip3-downconverting-mixer-boasts-a-2-4db-conversion-gain/6/883
milstar: The LTC5551 consists of a high linearity double-balanced mixer core, IF buffer amplifier, LO buffer amplifier and bias/enable circuits. See the Block Diagram section for a description of each pin function. The RF and LO inputs are single-ended. The IF output is differential
milstar: https://www.fairviewmicrowave.com/images/productPDF/FMMX9000.pdf
milstar: https://www.analog.com/media/en/technical-documentation/data-sheets/2107fb.pdf https://www.analog.com/media/en/technical-documentation/data-sheets/238718fa.pdf https://pdfserv.maximintegrated.com/en/an/AN1929.pdf
milstar: https://www.maximintegrated.com/en/app-notes/index.mvp/id/5429
milstar: High resolution analog to digital converters (ADCs) are rare commodities. They serve very specific markets that demand high dynamic range and good measurement accuracy, helping to provide accurate representations of real world signals in challenging noise environments. Up until recently, this market was largely served by delta-sigma ADCs, which are specialized devices that must be oversampled, resulting in very slow data output rates. This article introduces a new successive approximation register (SAR) ADC that combines both high resolution with high sample rate and exceptional 24-bit dynamic range, exceeding the dynamic range and measurement accuracy of its peers. The following applications are examples of how this high dynamic range can be put to good use. A medical application, like an encephalograph, may require the gathering of signals in the presence of high levels of noise; the electrical activity in a cell when stimulated, known as the action potential, can range from 10uV to 100mV at frequencies from 100Hz to 2kHz. If the signals are buried in the noise you need to average the samples to resolve the signal, requiring an ADC with high dynamic range. Seismology and seismic exploration are other demanding applications with common requirements. Seismometer and accelerometer signals can have a dynamic range of 140dB and frequencies up to 100Hz. The SNR of seismic signals received by sensors is very low due to absorption and attenuation by subsurface and deep layers during signal propagation. This creates a real challenge to measure these signals. A gas sensor must be able to detect very low concentrations of gas, alarming at detection levels as low as 0.5ppm. High accuracy and wide dynamic range is vital for this application to ensure toxic chemicals are detected swiftly, but also ensure alarms are not activated unnecessarily. Broader trends are also raising the data conversion bar. The move towards portable devices is resulting in increasingly complex data conversion tasks migrating to battery-powered devices. Designers must develop solutions using less space while simultaneously minimizing power consumption. For data conversion tasks, each of the common ADC architectures brings with it a list of advantages and drawbacks. Data Converter Architectures Analog-to-digital converter design mostly involves a series of compromises. For converters, a lot depends on the primary goal: high resolution, high speed, or low power consumption. Note: you can't necessarily pick all three! To cover the full spectrum of application requirements, multiple ADC architectures have appeared over the years, but there are three primary architectures in use today. The successive approximation register (SAR) architecture traditionally has been the workhouse, "go-to" architecture for mainstream analog-to-digital converter applications with low frequency signals. It provides the transition between high resolution, low speed delta-sigma architectures, and the high speed, lower performance, pipeline architecture. They are usually lower cost compared to pipelined ADCs, and consume a modest amount of power. The SAR converter shows no latency between successive conversions, so it is ideal for sampling multiplexed or non-periodic signals. Pipeline converters use a multi-stage sequential pipeline architecture to increase sampling speed. They rule the market at very high sample rates for acquiring wide signal bandwidths or signals at higher input frequencies, and on a per sample basis consume less power when compared to fast SAR ADCs. They're unsuited to handle multiplexed or non-periodic inputs because they have to "flush the pipe" every time the source changes, which adds considerable latency. The main rival to the SAR ADC for higher-resolution applications has been the delta-sigma converter; this relies on a delta-sigma modulator and a digital decimation filter. This architecture is slow compared to the SAR and is not as accurate. Most importantly, the noise spectrum of a delta-sigma ADC includes vibrating noise tones whereas the SAR ADCs noise floor has a uniform power spectral density. This makes SAR ADCs better for detecting tones or vibrations at incredibly low levels. Introducing the LTC2380-24 Despite its disadvantages, the relatively slow delta-sigma architecture has been the only option for high-resolution applications because SAR converters have traditionally not been available at resolutions above 18 bits. Recently, Linear Technology introduced the LTC2380-24, a SAR converter that combines high resolution (24-bits) with high sample rate (up to 2Msps). It's the flagship member of Linear Technology's LTC2380 family, which includes the 20-bit 1Msps LTC2378-20, the 18-bit 1.6Msps LTC2379-18 and the 16-bit 2Msps LTC2380-16 among others. All these parts come in the MSOP-16 and 4mm by 3mm DFN packages, and are pin-compatible. Part Number Package Temp LTC2380CDE-24#PBF 4x3 DFN-16 Commercial LTC2380CDE-24#TRPBF 4x3DFN-16 Commercial LTC2380CMS-24#PBF MS-16 Commercial LTC2380CMS-24#TRPBF MS-16 Commercial LTC2380IDE-24#PBF 4x3DFN-16 Industrial LTC2380IDE-24#TRPBF 4x3 DFN-16 Industrial LTC2380IMS-24#PBF MS-16 Industrial LTC2380IMS-24#TRPBF MS-16 Industrial The 24-bit precision, fast 2Msps sample rate and unparalleled ±0.5ppm (typ) linearity enables the LTC2380-24 to resolve very low-level input signals in high dynamic range applications such as ECG/EEG. The LTC2380-24 includes additional features that help simplify common design problems, such as a built-in digital filter and digital gain compression for single supply operation. Detailed technical specifications appear on the LTC2380-24 product page; this article will discuss some of the special features of the part and how they benefit target applications, as well as touch on a couple of application details. Digital Filtering For Averaging Many applications, such as seismic exploration, require the accurate measurement of a weak low-frequency signal in the presence of broadband noise. Oversampling the signal at a rate much higher than Nyquist, then averaging the result of multiple conversions, reduces the effect of this uncorrelated noise. Oversampling increases the effective dynamic range of the ADC by spreading out the noise across a wider bandwidth, thus reducing the noise spectral density in the bandwidth of interest. This also reduces the complexity of the front-end anti-aliasing filter, which results in less power being consumed and less noise and distortion being introduced. The LTC2380-24 features an integrated digital averaging filter that can provide this function without any additional hardware, simplifying the design and providing a number of unique advantages. The high sample rate of the LTC2380-24 makes this an option for many applications. The benefit to the user is that this frees up valuable resources in the processor to perform other tasks, while the averaged data can be transferred at much slower data rates (as low as 2Msps). The digital averaging filter used in the LTC2380-24 is known as a SINC1 filter. It can average blocks of conversions from as few as N = 1 to as many as N = 65,536. The results are dramatic, improving the dynamic range from 101dB at 1.5Msps, to true 24-bit performance of 145dB at 30.5sps as shown in figure 1. With 40.9nVrms/ √Hz noise spectral density, the LTC2380-24’s dynamic range in 1Hz of bandwidth is over 158dB! https://www.arrow.com/en/research-and-events/articles/24-bit-2msps-sar-adc-takes-dynamic-range-to-a-new-level
milstar: http://www.lucabarbi.it/product/winradio_pdf/G35DDCbrochure.pdf
milstar: For example, Figure 25.1 shows a simplified block diagram of the receiver front end of a typical radar system that would have been designed around 1990. Note that this system incorporated analog pulse compression (PC). It also included several stages of analog downconversion, in order to generate baseband in-phase (I) and quadrature (Q) signals with a small enough bandwidth that the ADCs of the day could sample them. The digitized signals were then fed into digital doppler/MTI and detection processors http://www.jocoleman.info/pubs/papers/SkolnikCh25.pdf
milstar: https://www.kit-e.ru/assets/files/pdf/2008_09_22.pdf
milstar: http://www.ti.com/lit/wp/snaa107/snaa107.pdf Processing gain can also be calculated by finding the noise floor of the ADC in dBm/Hz. With an IF of 244 MHz at -1 dBFS, the SNR of the ADC12DL080 is 65 dBFS or -55 dBm since full scale is +10 dBm into 50 W . To trans- late into dBm/Hz, take 10 * LOG (Fs/2) and subtract it from -55 dBm. 10 * LOG (39 MHz) = 75.9 dB, therefore the ADC12DL080 noise floor in this example is -130.9 dBm/Hz. Now if the channel bandwidth is 200 kHz, add back 10 * LOG (200 kHz) or 53 dB to get a noise floor of -77.9 dBm in 200 kHz, which is 22.9 dB better than the ADC by itself. Translating back to dBFS, the total SNR is 87.9 dB in a 200 kHz channel. This is similar to decreasing the resolution bandwidth on a spectrum analyzer; the noise floor has been lowered, but the ADC’s resolution has not been increased
milstar: https://arxiv.org/pdf/0807.0349.pdf time stretch ADC BW 10 ghz ENOB 7 bit ,SFDR 53 db
milstar: Note that the increased sampling rate does not dire ctly improve ADC resolution, but by providing more samples, this technique more accurately tracks th e input signal by better utilizing the existing ADC dynamic range. It should be clear that oversampling by itself improves the digital representation of the signal only down to the physical dynamic range limit (minimum step size) of the ADC https://www.microsemi.com/document-portal/doc_view/131569-improving-adc-results-white-paper
milstar: Analog Devices AD9467 16-bit ADC 2010 100 dBFS SFDR at 100 MHz at 160 MSPS (@ −1 dBFS) 60 fs rms Jitter 1.32W total power dissipation including drivers, The device is fabricated on .18 silicon germanium BiCMOS
milstar: A heterodyne receiver includes a first mixer (LO1) that converts the RF waveform to a first intermediate frequency (IF) signal ( Figure 1 ). This IF signal can either be digitized or fed to a second mixer (LO2) to convert the desired signal to an even lower IF. Converting the signal to a lower IF frequency takes advantage of the ADC's better noise and linearity performance, which is typically achieved at lower frequency inputs. A technique known as subsampling is used to digitize the real bandpass signal at a rate that meets the Nyquist criterion for the signal's bandwidth, but not for its absolute frequency. Using this technique, an ADC digitizes the real signal, which is then converted to its complex components in the digital domain using digital signal processing (DSP) methods. Advantages to this technique include reduced hardware complexity and cost. These advantages are possible because the subsampling method performs part of the downconversion task. However, this architecture requires an ADC with higher clocking speed and larger overall dynamic range (i.e., lower noise and higher linearity). Despite the benefits that subsampling techniques provide, one important drawback is noise aliasing. Such aliasing reduces the equivalent ADC SNR performance if the input signal is not sufficiently band limited, allowing noise in the alias bands to be digitized and converted to baseband along with the desired signal. https://pdfserv.maximintegrated.com/en/an/AN3717.pdf
milstar: https://www.teledyne-e2v.com/shared/content/resources/File/documents/broadband-data-converters/EV12AQ600/1203D_EV12AQ600%20preliminary%20datasheet%20(web).pdf in 4 channel mode 1 N zone Fin 778 mhz ,-1 dbfs SFDR 73.7 dbfs SNR 54.3 dbfs,averaged simul sampled 59.4 dbfs SINAD 53.8 averaged 59 ENOB 8.6 averaged 9.5 ========= 2 chan mode interleaved SFDR -64 SNR 53.9 SINAD 53.2 ENOB 8.6 ========== 1chan SFDR 63 SNR 53.9 SINAD 52.8 ENOB 8.5
milstar: https://www.teledyne-e2v.com/shared/content/resources/File/documents/broadband-data-converters/EV12AD550/EV12AD550B%20Datasheet.pdf
milstar: https://www.analog.com/media/en/technical-documentation/data-sheets/ad9697.pdf 14 bit 1300 msps APPLICATIONS Communications Diversity multiband, multi mode digital receivers 3G/4G, TD -SCDMA, W -CDMA, GSM, LTE General- purpose software radios Ultra wideband satellite receiver ============= 1.36 V p-p SFDR 10 mhz -81 dbfs 172 -81 340 -80 -------------- SINAD -64 =========== ENOB 10.3 ========= Noise Density -152.6
milstar: https://www.analog.com/media/en/technical-documentation/data-sheets/AD9213.pdf 12 bit ,10.25 GSPS Fin 1000 mhz SNR 55.1 SINAD 55 ENOB 8.8 SFDR 71 Input buffered pipelined ADC.
milstar: https://www.analog.com/media/en/technical-documentation/data-sheets/AD9695.pdf
milstar: http://www.astrosurf.com/luxorion/Radio/elecraft-k3-qst-review.pdf
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