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Signal Composition

Amplitude Modulation

modulation flow diagram

Many AWG applications require sinusoidal signals with shaped pulse envelopes. The UHFAWG features amplitude modulation, thus offering independent control over carrier and envelope. Internal oscillators ensure phase coherence during long pulse sequences independently from the envelope signal generated by the AWG engine. Combining the UHFAWG with the UHFLI Lock-in Amplifier gives access to pulsed modulation and fast demodulation within the same instrument – a powerful solution for pulsed phase-coherent measurements that is unique to Zurich Instruments.

The diagram below illustrates the possibilities for output generation. The basic version of the UHFAWG offers the choice between direct output and amplitude modulation of 1 oscillator per signal output. Adding the UHF-MF Multi-Frequency option extends the modulation capabilities of the UHFAWG in the form of an upgrade to 4 oscillators per channel. Further, the UHF-MF output adder makes it possible to combine the 2 AWG and pure oscillator signals on a single signal output. Multiple oscillator signals can be added and modulated not only simultaneously but also sequentially by using fast oscillator switching between pulses. This unique feature enables multi-frequency techniques for pulsed laser spectroscopy, NEMS/MEMS, and more. 

Synchronous Operation

example modulation pattern of the HDAWG Arbitrary Waveform Generator

Internal oscillators can also act as triggers for the AWG, enabling precise control over the AWG pulse repetition rate. The figure below illustrates the signal generation using 2 oscillators as time bases: oscillator 1 serves as carrier, whereas oscillator 2 defines the pulse repetition rate.

When combining the UHFAWG with the UHFLI, all oscillators can be phase-locked to external sources or, vice versa, used to generate a reference signal on an output channel. This unique feature extends the application potential for the UHFAWG when it is used with external devices such as lasers, scanners, radar or NMR equipment.

The versatility afforded by modulation, triggering, and user registers for adjusting signal parameters is unmatched by competing AWGs. Every parameter change that can take place on the fly speeds up the measurement routine dramatically.

Room for More Channels

For applications requiring more channels and/or higher voltages, the UHFAWG can generate signals on its auxiliary outputs. To this end, the AWG resources for 1 fast channel (1.8 GSa/s) can be reallocated to generate 4 independent signals at 14 MSa/s and 16-bit resolution in a ±10 V range. This is ideal for driving NMR gradient coils during a pulsed experiment, for example.