Custom Arb Waveform Generator

Working with Filters

Restoring Default FIR Filter Parameters

1.Preset the instrument: Press Preset.

2.Press Mode > Custom > ARB Waveform Generator > Digital Mod Define > Filter > Restore Default Filter. This replaces the current FIR filter with the default filter for the selected modulation format.

Using a User-Defined FIR Filter

FIR filters can be created and modified by defining the FIR coefficients or by defining the oversample ratio (number of filter coefficients per symbol) to be applied to your own custom FIR filter.

To Modify Predefined FIR Coefficients for a Gaussian Filter Using the FIR Values Editor

You can define from 1 to 32 FIR coefficients, where the maximum combination of symbols and oversample ratio is 1024 coefficients. While the FIR Values editor allows a maximum filter length of 1024 coefficients, the PSG hardware is limited to 64 symbols for real-time and 512 symbols for arbitrary waveform generation (the number of symbols equals the number of coefficients divided by the oversample ratio).

If you enter more than 64 symbols for real-time or 512 symbols for arbitrary waveform generation, the PSG cannot use the filter; it will decimate the filter (throw away coefficients) until the required condition is met and then use the filter, but fine resolution may be lost from the impulse response.

FIR filters stored in signal generator memory can easily be modified using the FIR Values editor. In this example, you will load the FIR Values editor with coefficient values from a default FIR filter (or, if one has been defined, a user-defined FIR file that has been stored in the Memory Catalog), modify the coefficient values, and store the new file to the Memory Catalog.

1.Press Preset.

2.Press Mode > Custom > Arb Waveform Generator > Digital Mod Define > Filter

or

Mode > Custom > Real Time I/Q Baseband > Filter

3.Press Define User FIR > More (1 of 2) > Load Default FIR > Gaussian.

4.Press Filter BbT > 0.300 > Enter.

5.Press Filter Symbols > 8 > Enter.

6.Press Generate.

NOTE

The actual oversample ratio during modulation is automatically selected by the instrument.

 

A value between 4 and 16 is chosen dependent on the symbol rate, the number of bits

 

per symbol of the modulation type, and the number of symbols.

 

 

Chapter 6

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Agilent Technologies E8257C PSG, E8267C PSG manual Using a User-Defined FIR Filter, Restoring Default FIR Filter Parameters
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E8267C PSG, E8247C PSG CW, E8257C PSG specifications

Agilent Technologies, a leading provider of electronic test and measurement equipment, offers a range of signal generators that are pivotal in various applications, including telecommunications, aerospace, and research. Among their top-tier offerings are the E8257C PSG, E8247C PSG CW, and E8267C PSG. These signal generators are known for their exceptional performance, flexibility, and cutting-edge technologies.

The E8257C PSG is a high-performance microwave signal generator capable of generating signals from 10 MHz to 40 GHz. Its versatility makes it ideal for applications such as radar and satellite communications. One of the standout features of the E8257C is its low phase noise and superior output power, which ensure high-quality signal generation. The instrument incorporates advanced digital signal processing technology, allowing users to create complex modulated signals with precision. It also boasts a comprehensive set of modulation formats, including AM, FM, PM, and pulse modulation, making it suitable for diverse testing scenarios.

The E8247C PSG CW is designed specifically for continuous wave (CW) applications, covering frequencies from 500 kHz to 20 GHz. This generator is optimized for high stability and low output noise, making it ideal for applications that require a reliable signal source, such as manufacturing testing and maintenance of communication systems. The E8247C features a compact design and is equipped with an intuitive user interface, allowing quick access to essential functions. Its frequency agility and fast switching capabilities enhance productivity, enabling engineers to optimize their workflow.

The E8267C PSG delivers unparalleled performance in the microwave frequency range of 250 kHz to 70 GHz. It includes advanced modulation capabilities, allowing users to generate complex waveforms with relative ease. The E8267C supports various digital modulation schemes, including QAM, which is crucial for testing modern communication systems. Its high output power and excellent spectral purity make it suitable for both R&D and manufacturing applications. Additionally, the E8267C features built-in functionality for frequency and power sweeps, providing users with extensive testing options.

In summary, Agilent Technologies’ E8257C, E8247C, and E8267C signal generators are integral tools for professionals seeking high performance and versatility in their testing environments. With unique features and advanced technologies, these generators cater to the demands of modern applications, ensuring reliable and accurate signal generation for a wide range of industries. Whether it's for research, development, or manufacturing, these instruments demonstrate Agilent's commitment to delivering top-notch testing solutions.
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