Block Diagram Theory of Operation

Block Diagram 1

The primary measurements of the A9 Global Test and Demod assembly are phase, frequency, and amplitude information of the 0.3 GMSK modulation signals. The A9 Global Test and Demod assembly measures these by digitizing the 700 kHz IF signal and using high speed DSP hardware and algorithms. The DSP hardware must be “armed” and then “triggered” to synchronize with the incoming modulation signal. These various trigger signals are shown on Block Diagram 1 and the operation of these is described in the HP/Agilent 8922 Users Guide.

The results of these measurements are displayed using the DSP ANL screen on the HP/ Agilent 8922. The digital data information is also used by the HP/Agilent 8922E/F/G/H to setup and maintain a call with a GSM mobile phone. This is done in “real time” as the HP/ Agilent 8922E/F/G/H and mobile phone simultaneously send and receive from each other.

A18 Spectrum Aanalyzer

The A18 Spectrum Analyzer assembly receives the 114.3 MHz signal from the A16 Receiver assembly. The analyzer can only view frequency spans up to 4 MHz due to the bandwidth of this input signal. A phase lock loop inside the spectrum analyzer is used to downconvert the 114.3 MHz signal which is then amplified, filtered, and detected. The synchronization signal for the display is controlled by the A19 Measurement assembly. This causes the PLL signal to sweep across the frequency span selected. In addition to normal spectrum analysis, the HP 8922 spectrum analyzer is used to help measure the amplitude profile of the pulsed GSM signal. The upper 30 dB of the pulse envelope is accurately determined by the A9 Global Test and Demod assembly, however, the lower level portions of the pulse amplitude is measured with the wide dynamic range of the A18 Spectrum Analyzer assembly.

This internal spectrum analyzer is a useful tool to view the incoming RF signal and verify that the A23 Input and A11 Receiver Mixer assemblies are working correctly. The A18 Spectrum Analyzer assembly contains diagnostic test points to verify gain, attenuation, and bandwidth controls. Because of the wide dynamic range of the A18 Spectrum Analyzer assembly it is used by the diagnostics to measure pulse on/off ratio of the A12 Pulse Attenuator assembly.

A2 Audio Analyzer 2 A3 Audio Analyzer 1

These modules are leveraged from an earlier product, the HP/Agilent 8920A, which is primarily an analog communications test set. Many of the audio circuits in these assemblies are not used by the HP/Agilent 8922 and will not be covered in this discussion. Refer to the HP/Agilent 8920A Assembly Level Repair manual if further detail on these modules is required.

For the HP/Agilent 8922, the primary function of these assemblies is to provide the oscilloscope functions. The HP/Agilent 8922 contains no specialized oscilloscope module, only these two analyzer assemblies and the A19 Measurement assembly. These

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Agilent Technologies 8922 manual A18 Spectrum Aanalyzer, A2 Audio Analyzer 2 A3 Audio Analyzer
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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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