Block Diagram Theory of Operation

Block Diagram 2

Block Diagram 2

RF Generator

AF Generator

A15 Reference

The A15 Reference assembly contains the circuits necessary to generate reference signals for the other assemblies in the HP/Agilent 8922. The A15 Reference assembly can be locked to an external signal of 1, 2, 5, 10 or 13 MHz or can operate without an external reference by using its own 10 MHz TCXO.

An optional high stability oscillator (Option 001) is available for the HP/Agilent 8922 that provides a more accurate and stable reference. The output from this oscillator is routed to the rear panel, where it must be connected to the Reference Input for the HP/Agilent 8922 to lock onto this signal. The frequency of the (optional) high stability timebase is adjusted with a screwdriver while the (standard) internal Temperature-Compensated Crystal Oscillator (TCXO) is adjusted by setting internal DAC values. Both of these adjustments are thoroughly explained in chapter 7, Adjustments and Calibration.

If the A15 Reference assembly is replaced, an error message “Frequency Reference Calibration Lost” will be seen during instrument power-up. It is necessary to perform the adjustment for the internal TCXO to remove the error message and restore calibrated operation.

A special feature of the A15 Reference assembly is the ability to offset all reference signals in the HP/Agilent 8922. The amount of offset can be set by the user by changing the A15 Reference assembly DAC value. The primary screen to control operation of the A15 Reference assembly is the Configure Screen; refer to the Users Guide for a more complete discussion on the operation of the Reference section.

Diagnostic procedures for the A15 Reference assembly check lock detectors to make sure that the internal loops are locked, and level detectors to check if RF power is available on key reference signals. The diagnostics cannot check the frequency accuracy of the internal oscillators.

A5 Premod Filter and NSM

The A5 Premod Filter and NSM assembly contains the necessary circuits to convert the user’s digital input data and clock signals into a GMSK waveform. The inputs to the module are a very accurate 270.833 kHz clock signal and digital TTL level data. On the HP/Agilent 8922A these two signals are provided directly by the user at the front panel; on the other HP/Agilent 8922’s, these signals are generated by other assemblies.

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Agilent Technologies 8922 manual A15 Reference, A5 Premod Filter and NSM
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8922 specifications

Agilent Technologies 8922 is a versatile and robust mobile communication test set, designed to fulfill the demanding requirements of wireless device manufacturers and service providers. Primarily focused on mobile radio communications, the 8922 provides a comprehensive solution for testing a wide array of signaling standards and technologies, making it essential in the rapidly evolving telecommunications landscape.

One of the standout features of the Agilent 8922 is its support for multiple wireless standards, including GSM, GPRS, EDGE, WCDMA, and HSPA. This makes the device an ideal choice for testing mobile devices that operate on different generations of cellular networks. Additionally, the 8922 is equipped with advanced measurement capabilities, allowing users to perform key performance indicators assessments, such as power, modulation quality, and spectral emission analysis, ensuring devices meet stringent regulatory and performance standards.

The 8922 is designed with an intuitive user interface that simplifies the setup and execution of tests. It features a large color display, making it easier for users to view test results and navigate through various functions. The built-in automation capabilities enable seamless integration into production environments, where efficiency and repeatability are crucial for high-volume testing.

Technologically, the Agilent 8922 incorporates advanced signal processing algorithms, which enhance its measurement accuracy and speed. The device's architecture allows for real-time analysis of signals, enabling users to identify issues quickly and efficiently. This is particularly important in the realm of mobile communications, where time-to-market is critical for competitive advantage.

Another significant characteristic of the 8922 is its flexible configuration options. Users can customize the test set with different hardware and software modules to suit specific testing needs. This scalability ensures that the 8922 remains relevant as wireless technologies evolve and new standards emerge.

In conclusion, the Agilent Technologies 8922 is an indispensable tool for professionals engaged in the testing of mobile communications devices. Its broad support for multiple standards, advanced measurement capabilities, user-friendly design, and flexibility make it a top choice in the telecommunications testing community. As the mobile communication industry continues to advance, the 8922 stands out as a leading solution for ensuring that devices meet quality and performance expectations.
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