Arbitrary waveform generators (AWGs) are ideal for producing the many modulation formats used in military electronic systems, including sawtooth and pulsed waveforms. One of the newer AWGs on the market is the model 81180A from Agilent Technologies (www.agilent.com), with a clock frequency range of 10 MSamples/s to 4.2 GSamples/s. It offers a variety of operating modes and can even run programmed sequences of different waveform sections to fully "exercise" a component or system under test.
The model 81180A AWG (see figure) is based on a high-speed digital-to-analog converter (DAC) with 12-b vertical resolution. It can operate in continuous, triggered, and gated modes, A standard operating mode selects a waveform (from 10 kHz to 250 MHz) from a built-in library using an integral function generator, while an arbitrary waveform mode downloads and stores in memory coordinates for a waveform. Arbitrary waveforms can also be downloaded as sequences of different waveforms and waveform segments.
The AWG can be used as a single-channel or dual-channel instrument, with the two channels coupled or uncoupled. In addition, a pair of dual-channel AWGs can be fully synchronized to form a four-channel system. The timing between channels (skew) can be adjusted from -3 to +3 ns with 10 ps resolution. Two markers are provided for each channel to control timing and offsets.
The AWG features a choice of three software-selectable output amplifiers, for different applications. One is optimized for in-phase/quadrature (I/Q) digital modulation generation with a differential DC-coupled output port with flat amplitude response across a 1-GHz bandwidth. Another output provides an AC-coupled single-ended output with bandwidth approaching 1.5 GHz for direct generation of RF signals, while a third output is optimized for time-domain applications with low overshoot and jitter transition times as low as 600 ps. The 1.5-GHz RF output provides signal levels from-5 to +5 dBm with 1 dB typical flatness. Each channel is supported by 16 or 64 Mpoints of memory for waveform storage. Advanced sequences can be created by combining different waveforms and portions of waveforms, using an 8-b external input for sequence control. The dynamic control connector lets real-time applications control the waveform and allows external select sequences.
The AWG's 12-b resolution arms it with the outstanding dynamic range needed for testing many military electronic systems and components. Harmonic levels are -50 dBc and nonharmonic spurious levels are -65 dBc. The single-sideband (SSB) phase noise is better than -90 dBc/Hz offset 10 kHz from the carrier. The model 81180A AWG achieves accuracy of 1 PM using internal frequency reference, but can also be used with an external reference source when higher accuracy is needed.
The model 81180A AWG offers a variety of remote control interfaces, including Ethernet local area network (LAN), General-Purpose Instrument Bus (GPIB), and Universal Serial Bus (USB) ports. It is LXI Class C compliant and fully controllable via an Internet interface. It also is compatible with leading waveform-generation software tools, including Matlab from The MathWorks (www.mathworks.com), LabView from National Instruments (www.ni.com), and Agilent Signal Studio from Agilent Technologies.
Agilent Technologies, 5301 Stevens Creek Blvd., Santa Clara, CA 95051; (877) 424-4536, (408) 345-8886, FAX: (408) 345-8474, Internet: www.agilent.com.