Introduction to test instrument selection indicators

　　Take digital oscilloscopes as an example. Many users may know some traditional indicators of oscilloscopes, such as bandwidth, sampling rate, memory depth, etc. Some even compare the indicators when selecting models, thinking that the ones with larger numbers are better than the ones with smaller numbers. This is not the case! To truly understand digital oscilloscopes, we must deeply understand the real performance and quality of the products hidden behind the nominal indicators, just like many consumers often care about the number of pixels when buying digital cameras. In fact, in addition to this "number", there are many (more) important indicators and even materials that need to be considered.

　　These parameters are very important in terms of scalability, the number of communication standards supported, test accuracy, dynamic range and demodulation bandwidth. In the future, base stations may evolve towards dual-mode and multi-mode. Many mobile phones already have multi-mode functions, such as GSM and WCDMA dual-mode mobile phones. If the instrument supports more communication standards, the variety and quantity of instruments to be purchased will be greatly reduced. In addition, with the emergence of technologies such as 3G and LTE, higher requirements are placed on instruments. Instruments with high test accuracy, large dynamic range and large demodulation bandwidth are very popular. Mobile communication technology is developing rapidly. At present, there is no large-scale commercial use of 3G in China, and LTE, as a follow-up technology of WCDMA and TD-SCDMA, is about to launch a prototype. Network operators may accelerate the introduction of new technologies, which is indeed a challenge for base station and terminal manufacturers: the test instruments they purchase now must have good scalability and can be easily upgraded to future technologies, so as to protect the manufacturer's investment to the greatest extent.

　　For example, Rohde & Schwarz's signal sources, signal analyzers and mobile phone integrated testers support almost all communication standards and are designed with testing needs in the next few years (a common requirement is demodulation bandwidth). For new communication standards, generally only software upgrades are required to implement them.

　　In addition, the bandwidth and sampling rate of the oscilloscope are common parameters of the oscilloscope. Due to the development of manufacturing and R&D technology, the bandwidth of the oscilloscope can be corrected and compensated. However, these corrections and compensations are not always good things. Some customers do not want to bring these technologies into the test. They need more original test data, such as radar experiments. At present, Tektronix provides pure hardware oscilloscopes in the full range of 1G~2G oscilloscopes. The oscilloscope bandwidth is the most real. Tektronix's front-end technology can ensure that the hardware preamplifier of the oscilloscope is good enough. The sampling rate is an indicator of ADC. The capture rate parameter reflects a concept of memory management (whether the required signal can be found in the saved signal). Tektronix uses segmented management to save information when the signal jumps. Including Inspector and other methods.

　　Nowadays, electronic engineers are more concerned about whether the instruments they purchase can truly solve the actual problems encountered in the test. "Solving problems" is the real value of the oscilloscope, rather than listing cold hardware indicators. LeCroy oscilloscopes are specially designed for "solving problems", which is specifically reflected in: the latest patented technology TriggerScan used in the 7Zi series oscilloscopes can capture abnormal signals through fast refresh methods more than 20 times more efficient than traditional methods, which greatly improves the efficiency of engineers debugging circuits; long waveform acquisition and instrument response capabilities have always been contradictory oscilloscope performance indicators. Some manufacturers claim that their products can reach a storage depth of hundreds of megabytes or even gigabytes, but in fact, when users use so much memory, the response of the oscilloscope will become slower, and any simple operation such as vertical sensitivity adjustment will make users wait for a long time to see the results. LeCroy uses a specially optimized waveform processing algorithm in the 7Zi oscilloscope, which greatly improves the fast response performance of the oscilloscope under deep memory operation conditions.