The oscilloscope is a graphic display device that depicts a wave curve of a telecommunications number. This simple waveform describes many of the characteristics of the signal: the time and voltage value of the signal, the frequency of the oscillation signal, the frequency of the specific part of the signal representing the “changed part” of the circuit relative to the frequency of the other parts, the existence of faulty components that cause the signal to be distorted, the direct flow component of the signal (dc) and the communication component (ac), the noise value of the signal and its change over time, the comparison of multiple wave signals, etc。
1. Development of oscillators
The initial period was mainly a simulation of the oscilloscope
In the 1940s, when electronic oscilloscopes emerged, radar and television development required well-performing wave-shaped observation tools, and tec succeeded in developing a synchronous oscilloscope with a bandwidth of 10 mhz, which was the foundation of the modern oscilloscope. The advent of semiconductors and computers in the 1950s facilitated the bandwidth of electronic oscillators to 100 mhz. In the 1960s, the united states, japan, the united kingdom and france made different contributions in the development of electronic oscilloscopes, with 6 ghz of bandwidth, 4 ghz of bandwidth, 1 ghz of storage oscilloscopes; portable, plug-in oscilloscopes became a series of products. An analog electronic oscillator peaked in the 1970s and the line spectroscopy series was very complete, with multifunctional plug-in oscillators with a bandwidth of 1ghz marking the high level of science and technology at the time, adding logical oscillators and digital wave recorders to test digital circuits. The simulation of oscillators has not progressed much since then, giving way to digital oscillators, and even to the exit of the united kingdom and france from the oscillator market, with technology leading in the united states and medium- and low-end products produced in japan。
Simulation oscilloscopes require a full propulsion of oscilloscopes, vertical magnification and horizontal scanning to increase bandwidth. Digital oscilloscopes need only improve the performance of the a/d converter at the front end to improve bandwidth, and there are no special requirements for oscilloscopes and scanning circuits. Add digital oscillator tubes that make full use of memory, storage and processing, as well as multiple trigger and pre-trigger capabilities. Digital oscillators surged in the 1980s, and the results were exhausting, with the general replacement of analogue oscillators, which gradually retreated backstage。
However, some of the characteristics of the analogue oscillators in the early stages of development are not available in digital oscillators:
Simple operation: all operations can be found on the panel, waves react in a timely manner, and digital oscillators often take longer to process。
Vertical resolution is high: continuous and unlimited, with digital oscillator resolution generally ranging from 8 to 10 bits。
Data update fast: hundreds of thousands of waveforms per second, and dozens of waveforms per second by digital oscillator。
Real-time bandwidth and real-time display: a continuous waveform is the same as a single wavelength, the bandwidth of a digital oscillator is closely related to the sampling rate, which is calculated by interpolation when the sampling rate is not high and is prone to confusion。
In short, simulators provide engineers with visible waveforms that can be tested with great confidence within the prescribed bandwidth. The eye-optic nerve of the five officers of the human race is very sensitive, the screen wave shape is instantaneous to the brain's judgement, and minor changes can be felt. As a result, analogue oscillators are very popular with users。
Medium-term digital oscillator monopolistic
Digital oscillators in the 1980s were in a transition phase and there was much to be done, and both the united states of america, tek and hp, contributed to the development of digital oscillators. They later ceased to produce analogue oscillators and only productive digital oscillators. In the 1990s, the digital oscillator, in addition to increasing its bandwidth to more than 1 ghz, was more important than a simulator. The phenomenon of so-called digital oscillator simulators occurs, in other words, maximizing the benefits of the oscillator and making it more useful。
The digital oscillator first increased the sampling rate from twice the bandwidth of the initial sampling rate to five or ten times, and the resulting distortion of the swirling sample decreased from 100 per cent to 3 per cent or even 1 per cent. The sampling rate for bandwidth 1 ghz is 5 ghz/s, or even 10 ghz/s。
Second, increasing the rate of updating digital oscillators to the same level as simulating oscillators, up to a maximum of 400,000 waves per second, has greatly enhanced the ability to observe occasional signals and to capture the pulsations of fur。
Third, multiple processors are used to speed up signal processing, to adjust from multiple menus of cumbersome measurement parameters, to improve to simple buttons, or even fully automatic measurements, as easy to use as simulators。
Finally, the digital oscillator, like the simulator, displays the remaining glitter of the screen in the three-dimensional state of wave shape, i. E., the magnitude of the signal, the time and the distribution of the range over time. A digital oscillator with this function is known as a digital fluorescent oscillator or a digital residual photo oscillator, i. E. A combination of numbers。
The digital oscillator needs a simulation
The analogue oscillator displays the wave shape with a cathode ray tube, with the same bandwidth as the analogue oscillator, i. E. The electronic motion rate of the oscillator is proportional to the frequency of the signal, the faster the frequency of the signal is, the brightness of the oscillator screen is inversely proportional to the speed of the electronic beam, the brightness of the low frequency wave shape and the brightness of the high frequency wave shape. The third dimension of the signal is easily accessible using the brightness or greyness of the fluorescent screen, where the range is expressed in the vertical axis of the screen and the time is expressed in the horizontal axis, and the brightness of the screen represents a change in the signal range over time distribution. This time-related fluorescent residual (grey-scaled) effect is very effective in observing mixed and impervious wave shapes. Simulation storage oscillators are the representative product of this dedicated oscillator, with a maximum performance of 800 mhz bandwidth, and can be recorded in fast transient events around 1ns.
The digital oscillator lacks the remaining light display because it is digitally processed, with only two states, non-high or low, and, in principle, waveforms are also shown both " yes " and " none " . To achieve multilevel brightness changes like simulators, dedicated image processing chips, such as the dpx processing chip used by tek, with multiple features such as data acquisition, image processing and storage, consisting of 1. 3 million transistor tubes, the cmos process of 0. 65 m, parallel flow structures, and high sampling rates, must be used. It is both a data-collection chip and a raster scanner that simulates the fluorescent properties of the oscilloscope screen, stores the wave shape on a single or colour colour screen of 500 x 200 pixels, updated every 1/30 seconds, using a 16-degree brightness rating. Since analogue storage oscillators can only rely on photo-film recording waves, data preservation is not easy, while digital fluorescent oscillators are digitally processed displays, data recording, processing and preservation are easy. For example, the highest probability waveform is shown in red and the lowest probability waveform is shown in blue. Since the digital oscillator has reached the level of bandwidth above 4ghz, combined with the fluorescent display properties, the overall performance is better than that of the simulated storage oscillator。
Digital fluorescent oscillator
A digital fluorescent oscillator (dpo) has added a new type to the oscillator series, allowing real-time display, storage and analysis of 3d signal information on complex signals: range, time and range distribution over the entire time。
Dso captures, displays and analyses signals using a symmetrical structure; in relative terms, the dpo uses parallel structure for these functions, as shown in figures i and ii. Parallel structures and processing techniques based on asic hardware enable digital fluorescent oscillators to capture all the details and anomalies in today's complex dynamic signals and to show them at the rate of acceptance of human eyes。
The normal digital oscillator, which takes a long time to record and then signal processing to observe an occasional event, omits the non-cyclical signal and the dynamic properties of the signal that cannot be shown. Digital fluorescent oscillators can show fine differences in complex wave shapes and frequency of occurrence. For example, observing television signals, ranging from line scans, frame scans, video signals and acoustic signals, and recording anomalies in television signals are equally important for professionals and maintenance personnel。
For example, the tds 3000 series digital fluorescent oscillator of tek provides multiple test modules that can be inserted from the top right corner of the front plate. For example, the trigger module can act as a logical state, a logical graphic trigger, and pulse parameters (up, down, width, periodicity, etc.); the television module is dedicated to multiform (ntsc, pal and secam) wave-shaped records; and the fast-track fourier transformation (fft) module can quickly show frequency components and spectrum distribution of signals, both for pulse response and for harmonization distribution, and to identify and locate sources of noise and interference. There are also advanced analysis and end-test modules。
