Making Basic Measurements

Measuring Signal-to-Noise

Measuring Signal-to-Noise

The signal-to-noise measurement procedure below may be adapted to measure any signal in a system if the signal (carrier) is a discrete tone. If the signal in your system is modulated, it will be necessary to modify the procedure to correctly measure the modulated signal level

In this example the 50 MHz amplitude reference signal is used as the fundamental source. The amplitude reference signal is assumed to be the signal of interest and the internal noise of the analyzer is measured as the system noise. To do this, you will need to set the input attenuator such that both the signal and the noise are well within the calibrated region of the display.

Signal-to-Noise Measurement Example:

Perform the steps below to measure the signal-to-noise.

1.Perform a factory preset by pressing Preset, Factory Preset (if present).

2.Turn on the internal 50 MHz amplitude reference signal of the analyzer as follows:

•For the E7401A, use the internal 50 MHz amplitude reference signal of the analyzer as the signal being measured. Press

Input/Output, Amptd Ref (On).

•For all other models connect a cable between the front-panel AMPTD REF OUT to the analyzer INPUT, then press

Input/Output, Amptd Ref Out (On).

3.Set the center frequency to 50 MHz by pressing FREQUENCY,

Center Freq, 50, MHz.

4.Set the span to 1 MHz by pressing SPAN, Span, 1, MHz.

5.Set the Y-Axis Units to dBm by pressing AMPLITUDE, More, Y-Axis Units, dBm.

6.Set the resolution bandwidth to spectrum analyzer coupling by pressing BW/Avg, Res BW (SA).

7.Set the reference level to –10 dBm by pressing AMPLITUDE, Ref Level,

–10, dBm.

8.Set the attenuation to 40 dB by pressing AMPLITUDE, Attenuation, 40, dB.

9.Press Peak Search to place a marker on the peak of the signal.

10.Press Marker, Delta, 200, kHz to put the delta marker in the noise at the specified offset, in this case 200 kHz.

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Agilent Technologies E7401A, E7405A, E7402A, E7404A, E7403A Measuring Signal-to-Noise, Signal-to-Noise Measurement Example
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E7402A, E7405A, E7404A, E7401A, E7403A specifications

Agilent Technologies, a leader in test and measurement solutions, offers a range of spectrum analyzers designed to meet the evolving demands of the electronics industry. The E7403A, E7401A, E7404A, E7405A, and E7402A are prominent models that embody advanced features and technologies, enhancing performance, accuracy, and user experience.

The E7403A is recognized for its high-quality performance and wide frequency range. This model offers frequency coverage from 9 kHz to 3 GHz, making it suitable for both commercial and academic research applications. With a phase noise of -100 dBc/Hz at 10 kHz offset, it delivers exceptional sensitivity. The E7403A also features a built-in tracking generator, facilitating effective signal generation for testing.

Next in line, the E7401A provides similar frequency coverage but is optimized for portable functionality. Weighing significantly less than its counterparts, it is easy to transport, making it ideal for field applications. Users benefit from its fast sweep speed of up to 3 GHz, which is crucial in quickly identifying and analyzing signals.

The E7404A excels in its comprehensive analysis capabilities. With a frequency range extending up to 6 GHz, it supports more demanding applications, including wireless communications and satellite technology. Its advanced digital signal processing capabilities enable the analysis of complex modulated signals, providing engineers with the data needed to troubleshoot and optimize system performance.

The E7405A is a highly versatile model that offers frequency coverage from 9 kHz to 20 GHz. This wide frequency range, combined with high dynamic range, supports the testing of various electronic devices and systems. It features advanced measurement options including occupied bandwidth, adjacent channel power, and sensitivity measurements, which are critical for compliance testing in communication systems.

Lastly, the E7402A is designed for users who require a spectrum analyzer with enhanced functionality at a competitive price. It reaches frequencies of up to 1.5 GHz, making it suitable for various applications including RF design, development, and manufacturing. Its user-friendly interface ensures that both novice and experienced users can navigate its features with ease.

In conclusion, Agilent Technologies' E7403A, E7401A, E7404A, E7405A, and E7402A spectrum analyzers provide a robust set of features tailored to meet diverse industry needs. Utilizing sophisticated technologies, these models ensure precise and efficient signal analysis, making them indispensable tools for engineers and researchers in the fast-paced world of electronics.
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