Optimizing Performance

Creating and Applying User Flatness Correction

For example, leveling the CW output of a 30 dB gain amplifier to a level of 10 dBm requires the output of the signal generator to be approximately 40 dBm when leveled. This is beyond the amplitude limits of the ALC modulator alone, resulting in an unleveled RF output. Inserting 45 dB of attenuation results in an ALC level of +5 dBm, well within the range of the ALC modulator.

NOTE In the example above, 55 dB is the preferred attenuation choice, resulting in an ALC level of +15 dBm. This provides adequate dynamic range for AM or other functions that vary the RF output amplitude.

To achieve the optimum ALC level at the signal generator RF output of 40 dBm for an unmodulated carrier, follow these steps:

1.Press Amplitude > Set Atten > 45 > dB.

2.Press Set ALC Level > 5 > dBm.

This sets the attenuator to 45 dB and the ALC level to +5 dBm, resulting in an RF output amplitude of - 40 dBm, as shown in the AMPLITUDE area of the display.

To obtain flatness- corrected power, refer to “Creating and Applying User Flatness Correction” on page 123.

To Level with a mm-Wave Source Module

Millimeter- wave source module leveling is similar to external detector leveling. The power level feedback signal to the ALC circuitry is taken from the millimeter- wave source module, rather than the internal signal generator detector. This feedback signal levels the RF output power at the

mm- wave source module output through the signal generator’s rear panel SOURCE MODULE interface connector.

For instructions and setups, see Chapter 11, “ Peripheral Devices,” on page 203.

Creating and Applying User Flatness Correction

User flatness correction allows the digital adjustment of RF output amplitude for up to 1601 frequency points in any frequency or sweep mode. Using an Agilent E4416A/17A or E4418B/19B power meter (controlled by the signal generator through GPIB) to calibrate the measurement system, a table of power level corrections is created for frequencies where power level variations or losses occur. These frequencies may be defined in sequential linear steps or arbitrarily spaced.

To allow different correction arrays for different test setups or different frequency ranges, you may save individual user flatness correction tables to the signal generator’s memory catalog and recall them on demand.

Use the steps in the next sections to create and apply user flatness correction to the signal generator’s RF output.

Afterward, use the steps in “Recalling and Applying a User Flatness Correction Array” on page 127 to recall a user flatness file from the memory catalog and apply it to the signal generator’s RF output.

Chapter 4

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Agilent Technologies E8257D PSG Creating and Applying User Flatness Correction, To Level with a mm-Wave Source Module

E8267D PSG, E8257D PSG specifications

Agilent Technologies, a recognized leader in electronic measurement and communications solutions, offers a comprehensive range of signal generators, including the E8257D PSG (Pulsed Signal Generator) and E8267D PSG. These instruments are engineered to meet the demanding requirements of wireless communication, aerospace, defense, and various research applications.

The E8257D PSG is known for its versatility and reliability. It operates within a frequency range of 250 kHz to 40 GHz, making it suitable for a wide array of applications, from signal generation to vector modulation. With an output power capability of up to +30 dBm, it delivers high-quality signals with exceptional precision. Its low phase noise performance is especially critical for applications such as radar and communication system testing, where signal integrity is paramount.

One of the standout features of the E8257D is its advanced modulation capabilities, including analog and digital modulation schemes. This flexibility allows engineers to simulate real-world communications environments accurately. The PSG also features a built-in arbitrary waveform generator that enables users to create complex waveforms tailored to specific testing needs, providing a significant advantage in research and development.

On the other hand, the Agilent E8267D PSG is designed to cater to the needs of users requiring a combined signal generation and analysis solution. With the capability to generate signals from 250 kHz to 67 GHz, the E8267D is ideal for millimeter-wave applications, as well as testing next-generation wireless technologies.

This model includes features such as enhanced phase noise performance and faster switching speed, which are crucial for signal integrity in sophisticated networks. The instrument's intuitive user interface and powerful software integration facilitate effortless operation and automation, thereby improving workflow efficiency.

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