National Instruments 779058-04 PXI Waveform Generator

Known also as the PXI-5441, the National Instruments 779058-04 is an advanced 43 MHz arbitrary waveform generator built to handle a wide range of demanding applications. In addition to typical functions like sine, square, triangle, and ramp signals, this instrument can generate user-defined arbitrary waveforms. It also includes onboard signal processing capabilities like digital pre-filter gain, a numerically controlled oscillator (NCO), FIR and CIC interpolation filters, and I/Q mixing for quadrature digital upconversion.

The 779058-04 delivers outstanding performance with a close-in spurious free dynamic range (SFDR) of -91 dBc, sampling at a rate of 100 MS/s and with a resolution of 16 bits. It can therefore be used for applications that need for the creation of high-quality signals, like electronic warfare systems, radar, and prototyping, validation, and testing. Its maximum output range of 12Vpk-pk into a 50 Ω load and its capacity to generate general-purpose electrical test signals improve its adaptability for a number of test situations.

When compared to conventional GPIB-based instruments, the 779058-04 allows waveform downloads at up to 100 MB/s. This is made possible by the device's PCI bus communication with the host computer. The Synchronization and Memory Core (SMC) architecture, which synchronizes the generator with digitizers and digital waveform generator/analyzers, enables this high-speed data transfer, enabling the development of mixed-signal test systems. Additionally, a phase-coherent multi-channel generator may be created by synchronizing numerous generators, which makes it perfect for producing I/Q signals in applications like beam-forming antenna systems and MIMO (multiple-input multiple-output).

The 779058-04's onboard signal processing features allow for the addition of gain and offset imbalance impairments during signal creation thanks to independent I and Q pre-filter gain and offset controls. The FIR filter uses programmable coefficients such as flat, raised cosine, root raised cosine, Gaussian, or custom filters to shape waveform data, adjust for the CIC filter response, and interpolate the data by factors of 2, 4, or 8x. The CIC filter interpolates waveform data at factors ranging from 6x to 256x, thereby upsampling waveform data to a high sample rate.

For quadrature digital upconversion, the 779058-04's NCO generates sine and cosine waveform data with a 355 nHz frequency resolution and a 0.0055-degree phase resolution. This makes it possible to precisely regulate defects such quadrature skew and frequency inaccuracy by adjusting phase and frequency during waveform production.