Spectrum Analyzer is a testing device that is more prominent in this digital industry. This is one of the most important testing equipment to measure frequencies and other important parameters. This device measures the power of the spectrum of both known and unknown signals. Due to its numerous applications in the field of electrical and electronic measurements, this device has gained a lot of popularity in the digital industry. Spectrum Analyzer is used to test various circuits and systems that are operated at radio frequency levels.

What do you mean by spectrum analyzer?

Spectrum Analyzer is the key instrument for testing radio frequency, RF circuits, modules, and units. These instruments are used in various areas of the electronic and electrical stream, like RF design, general electronic circuit design, electronics manufacturing and test, and service, and sometimes in field repair. This test instrument plots amplitude vs. frequency and is useful for displaying and monitoring signal bandwidths as well as locating anomalous signals. Knowing how to use a spectrum analyzer correctly is essential for analyzing the operation of RF circuits.

What does a spectrum analyzer measure?

Spectrum Analyzer is used for:

. Measuring frequency response, noise, and distortion characteristics of all radio-frequency circuitry.

. Measure occupied bandwidth and interference sources in telecommunications.

. Basic pre-compliance testing for EMC testing.

Other measurement techniques involved include musicians and audio engineers setting up the spectrum analyzer to test the harmonics of audio signals, using reflective or refractive techniques to separate the wavelengths of light with the optical spectrum analyzer, and vibration amplitudes at various component frequencies, among many others. The measurement techniques may depend on the application, but hopefully, these basics are enough to start.

Working principle of signal spectrum analyzer –

This instrument measures the signal's spectrum strength, i.e., fed to the analyzer. For instance, if you are measuring the output of a filter, let us say the low pass filter, then the signal spectrum analyzer would measure the spectrum content of the output filter in the frequency domain. In this process, this device would also measure the noise content and display it in the CRO.

The operation of the spectrum analyzer can be described as producing a vertical and horizontal sweep on the cathode ray oscilloscope, given that the measured signal's horizontal sweep is frequency-relative and its vertical sweep is amplitude-relative. The signal at the radio frequency level is delivered to the input attenuator, which can attenuate the signal at the radio frequency level to generate the horizontal sweep of the measured signal. At the same time, the output signal of the attenuator is fed to the low-pass filter to eliminate any ripple content in the signal. After all this process, the signal is then fed to an amplifier, which amplifies the magnitude of the signal to a certain level.

In this process, this signal is also mixed with the oscillator's output, which is tuned at a certain frequency. Thus, the oscillator helps to generate an alternating nature of the fed waveform. This signal is transmitted to the horizontal detector, which translates it into the frequency domain after mixing with the oscillator and amplifier. The spectral quantity of the signal is described in terms of the frequency domain within the spectrum analyzer.

But in the case of the vertical sweep, the amplitude is required. This signal is supplied to the voltage-tuned oscillator to obtain its amplitude. This voltage-tuned oscillator is tuned at the radio frequency level. The oscillator circuits are created by combining resistors and capacitors, and this combination is known as RC oscillators. At the oscillator level, this signal gets phase shifted by 360 degrees. For this phase shifting, various levels of RC circuits are used.

However, transformers can sometimes be utilized for phase shifting. Most oscillators' frequencies are also controlled by a ramp generator, which is sometimes coupled to a pulse width modulator to produce a ramp of pulses. Thus the output of the oscillator is fed to the vertical sweep circuit, which provides amplitude on the cathode ray oscilloscope.

Use of a spectrum analyzer –

Given the challenges in describing the operation of modern RF devices, knowledge of the behavior of frequency, amplitude, and modulation parameters across short and long time intervals in a spectrum analyzer is essential. Traditional tools like Swept Spectrum Analyzer (i.e., SA) and Vector Signal Analyzer (i.e., VSA) provide snapshots of the modulating signal in the frequency or modulation domain.

The real-time spectrum analyzer (RTSA) architecture is aimed at overcoming the measurement restrictions of the SA and VSA in order to address the concerns similar to transient and dynamic RF signals more effectively. Prior to memory storage, the real-time spectrum analyzer performs signal analysis utilizing real-time digital signal processing (i.e., DSP). Real-time processing allows the user to discover events that are invisible to other architectures and helps to trigger those events that would enable their selective capture into memory. Thus, the data in memory can then be broadly analyzed in various domains using batch processing.

So, the aforementioned are some details about the spectrum analyzer and its working principle. So, if you are planning to buy a suitable one, look no further than AVCOM. We are one of the leading manufacturers of high-quality commercial spectrum analyzers and signal monitoring products across the US.

Contact our experienced team at (804) 794-2500 with your requirement.