What to do if overload on input error messages appear on Agilent Technologies 8720ES Measuring Instruments?
If you see 'Overload on input' error messages on your Agilent Technologies Measuring Instruments, it means you've exceeded approximately +14 dBm at one of the test ports. To resolve this, press the Power button and enter a lower power level. Then, press SOURCE PWR ON to switch the power back on.
What does it mean if trace data is below the noise floor of Agilent Technologies 8720ES Measuring Instruments?
If the trace data appears below the noise floor of the Agilent Technologies Measuring Instruments analyzer, this indicates a receiver failure.
Why am I getting phase lock error messages on my Agilent Technologies 8720ES Measuring Instruments?
Phase lock error messages on Agilent Technologies Measuring Instruments can be caused by a source failure or improper instrument configuration. Consult Chapter 7, “Source Troubleshooting.”
This document describes how to perform pulsed measurements using the Agilent 8720ES and 8753ES network analyzers, offering a cost-effective alternative to more specialized pulsed measurement systems. It details the theoretical basis for pulsed measurements, outlines two primary modes of operation—low PRF (Pulse Repetition Frequency) and high PRF measurements—and provides practical examples for both transmission and reflection measurements. The document also covers calibration considerations to ensure accuracy and discusses the advantages and limitations of using these analyzers for pulsed applications.
The Agilent 8720ES and 8753ES network analyzers are designed to characterize the frequency responses of various RF and microwave components. While primarily used for continuous wave (CW) signals, this product note demonstrates their capability to measure pulsed RF signals under specific conditions. The core function involves measuring S-parameters (scattering parameters) of a device under test (DUT), which describe how electrical power is transmitted through or reflected from a network.
For pulsed measurements, the analyzers operate by either sampling a wide pulse (low PRF) or by focusing on the central spectral line of a continuous pulse train (high PRF). In low PRF mode, the analyzer can capture the shape of a pulse over time (pulse-profile mode) or measure the DUT's frequency response at a specific point within each pulse (point-on-pulse mode). In high PRF mode, the analyzer effectively treats the pulse train as a single, continuous frequency, albeit at a reduced power level due to pulse desensitization.
The internal architecture of the analyzer, as depicted in the block diagram, includes a source, transfer switch, couplers, samplers (A and B), IF (Intermediate Frequency) filters, and an ADC (Analog-to-Digital Converter). The RF signal from the source passes through the transfer switch and port 1 coupler to the DUT. Transmitted signals go through the DUT, port 2 coupler, and into sampler B, while reflected signals return through port 1 coupler into sampler A. These signals are then down-converted to an IF, filtered by a variable bandwidth IF filter, and digitized for further digital processing. The IF bandwidth filter plays a critical role in determining the analyzer's response to pulsed signals, especially in high PRF measurements where it selects specific spectral lines from the pulse train.
The Agilent 8720ES and 8753ES offer several usage features for pulsed measurements, provided certain conditions are met.
While the document does not explicitly detail maintenance features, it implies that the Agilent 8720ES and 8753ES are robust instruments designed for reliable operation within specified parameters. The emphasis on proper calibration procedures and understanding the instrument's response to different signal types suggests that maintaining measurement accuracy is a key aspect of their use.
The document highlights the importance of ensuring the analyzer is completely set up with all hardware (pulse modulator, triggering circuit, etc.) and instrument settings complete before starting a calibration. This ensures that no additional errors are introduced into the system after calibration. Regular calibration, as described, is a form of preventative maintenance for measurement accuracy.
The mention of "Agilent Technologies' Test and Measurement Support, Services, and Assistance" at the end of the document indicates that users can rely on Agilent for support, including calibration, extra-cost upgrades, out-of-warranty repairs, and on-site education and training. This suggests that the devices are supported by a comprehensive service network to ensure their long-term functionality and accuracy. The global warranty and commitment to support for at least five years beyond production life further underscore the expected reliability and maintainability of these instruments.
General| Frequency Range | 50 MHz to 20 GHz |
|---|---|
| Output Power | +10 dBm |
| Impedance | 50 Ohms |
| Number of Ports | 2 |
| Test Port Output Power | +10 dBm |
| Display Type | Color LCD |
| Interface | GPIB, RS-232 |
| Weight | 23 kg |
To Next Page