Receivers and spectrometers are very versatile in wireless communication testing, and many tests can be performed independently, so what is the difference between the two? Let me give you a brief introduction:
1. Principle difference: Pre-preselection, local oscillator signal scanning, intermediate frequency filter, stray signal and precision
Receiver: is the main tool of EMC testing, based on the point-frequency method, the principle of the resonant tuning is used to test the level value of the corresponding frequency point, and the scanning mode of the receiver is tuned in step-by-point frequency.
Spectrum Analyzer: The main tool of spectrum analysis, sweep frequency heterodyne is the mainstream, using sweep-frequency measurement technology, the frequency sweep signal source to obtain the heterodyne signal dynamic analysis.
2, the input RF signal of the first paragraph processing is different:
Spectrum Analyzer: The signal input terminal usually has a simple set of Low-pass filters
Receiver: To use the wideband signal has a strong anti-interference ability preselection, usually includes a set of fixed often pass filter and a set of tracking filter to complete the preselection of the signal. The receiver requires a higher precision and requires more than one preselection device on the front of the receiver.
3, the Spectrum Analyzer is through the scanning signal source to achieve sweep frequency measurement, in the preset frequency range scanning, to obtain the desired mixed-frequency output signal.
The frequency scanning of the receiver is stepped, the discrete point-frequency test, according to the preset frequency interval, at each frequency point of the level measurement, the display curve is a single point frequency test results.
4. Intermediate Frequency Filter
Spectrum Analyzer: Resolution Bandwidth is the 3db bandwidth of amplitude-frequency characteristics.
Receiver: Intermediate frequency bandwidth is the 6db bandwidth of amplitude-frequency characteristic. According to EMC standards, the civilian military bandwidth is 6db.
Spectrum Analyzer: Generally only the peak and average geophone, there is no quasi-peak geophone,
Receiver: The EMC standard requires test receivers with peak, quasi-peak, and average geophone.
The receiver is more accurate than the spectrum meter, and the lower the realistic corresponding.
In the current market, there are a number of receivers through the transformation of the spectrum instrument, universal spectrum Instrument + preselection +6db if filter + three kinds of geophone + point-frequency test power + high-precision signal processing = Receiver
7. Point frequency Test and GeoPhone
Some fixed frequency points need to be tested in real time on the basis of EMC standard testing. For example, the radiation interference test, the need to select the appropriate frequency points, turntable rotation and the take-off and landing of the antenna, real-time fast observation and record a level value. The Universal Spectrum Analyzer cannot implement the test. The Spectrum analyzer for EMI testing must have increased functionality to enable fast and accurate testing at the scan span (span) of 0 o'clock.
8, receiver Advantages: High test accuracy, dynamic range, high frequency resolution, high sensitivity, intermodulation interference small and four kinds of basic detection methods; Disadvantage: Not like the spectrum analyzer in a wide range of frequencies to observe, the measured signal can not be fast spectrum analysis and amplitude test.
9, the advantages of the spectrum instrument: in a very wide frequency range observation, rapid measurement of the signal spectrum and amplitude testing, testing equipment is relatively simple, easy to test. Disadvantages: The test accuracy is relatively poor, the frequency resolution is low, intermodulation jamming is played, the selectivity is poor and only a single peak detection method.