Modulation generator answers research demands

The R and S AFQ100A I/Q modulation generator combines a memory clock of 300MHz with a memory depth of up to 1Gsample.

The R and S AFQ100A I/Q modulation generator combines a memory clock of 300MHz with a memory depth of up to 1Gsample.

Its outstanding signal quality and high flexibility make the R and S AFQ100A ideal for use in R and D and production where users need to generate complex digital modulation signals.

It is available with an output memory of 256Msample or 1Gsample, and in addition to analogue outputs, it can also be fitted with a digital I/Q output.

Modern communications technologies use a wide variety of digital modulation methods.

New modulation methods are continually being developed to achieve higher datarates.

As a result, a flexible modulation source that generates these complex signals is required for tests in both R and D and production.

Thanks to its variable memory clock rate of 1kHz to 300MHz and large memory depth of up to 1Gsample, the AFQ100A is ideally suited for these applications.

It allows I/Q signals with an RF bandwidth of up to 200MHz to be generated, thus also supporting the requirements of future broadband communications systems.

The R and S AFQ100A comes with an unbalanced analogue output that has a level that can be set from 0 to 1.5V and a balanced output that has a level varying between 0 and 3V.

A bias voltage of -2.5 to +2.5 V may additionally be superimposed on the signal at the balanced output.

Plus, the R and S AFQ100A can be equipped with digital outputs which offer 16bit resolution and support a maximum datarate of up to 300MHz.

The R and S AFQ100A achieves outstanding signal quality, with a typical SNR of 83dBc and typical frequency response of 0.05dB across the entire bandwidth.

The generator also features various trigger functions, and the output signal can be adjusted in various ways, for example to compensate for impairments.

If necessary, the internal equaliser changes the output signal in real time, compensating for external frequency responses of I/Q modulators, for example.

As an independent baseband source, the R and S AFQ100A provides the DUT with I/Q signals directly via an analogue or digital output.

In conjunction with a vector signal generator, the R and S AFQ100A also generates the appropriate RF signals.

The signal data can be output from the memory at a user-adjustable clock rate.

Users can select a very small clock rate to achieve maximum signal duration.

As there is no link to a specific part of the memory, the signal sequence length can be user-defined.

A multisegment waveform function allows fast switchover between the different signal sequences stored in the memory.

This feature is of special interest when testing a DUT with different signals.

In addition, the multisegment waveform function allows applications with baseband hopping to be performed.

The deep memory also generates very long sequences for measuring the bit error ratio.

The signals are generated on a PC using the R and S WinIQSIM2 software supplied with the R and S AFQ100A, or directly via the conventional Matlab PC software.

R and S WinIQSIM2 provides ready-made packages for a large number of communications standards.

The R and S AFQ100A can be controlled via GPIB, USB and LAN (gigabit Ethernet) or operated as a stand-alone instrument by using the integrated video, mouse and keyboard interface.

The R and S AFQ100A I/Q modulation generator is now available from Rohde and Schwarz.

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