Sine Wave generation. The evolution of high speed DSP devices has resulted in a wide variety of products intended for signal and function generation; operations that have traditionally been performed by analogue means. Signal Wizard 2.5 boasts a high precision, 24-bit resolution, dual channel sine wave generator. Sine waves in the frequency range from 1 Hz to 22 kHz may be generated with a resolution of 0.01 Hz. Both channels are completely independent from one another. Since they are synchronous to a common source, if one channel is generates a frequency that is an integer multiple of the other, it will be locked in phase. As with the other features of Signal Wizard, independent gain settings can be applied to each channel from 0 to 96 dB in steps of 0.6 dB. The sine wave generator also incorporates a modulator feature, in which channel 1 may be modulated by channel 2.

Rather than using a look-up table, Signal Wizard employs a unique interpolation algorithm to synthesize sine waves, resulting in exceptional purity and flexibility of performance. Total harmonic distortion (THD) analysis reveals that Signal Wizard has a consistently superior performance to typical bench top traditional analogue sine wave generators.

The sine wave generator function is simplicity itself to use. Select the Sine Wave tab from the Hardware Control Panel, select the desired frequency or frequencies using the sliders, and click the button labelled “sine”. The frequencies and gains can be altered in real time. What’s more, the settings can be saved at the click of a mouse so that the hardware module starts up with the saved frequencies and gains as soon as it is powered up, without the need of a computer.

The first plot shows a spectrum, plotted in dB scale, for a 1 kHz sine wave generated using Signal Wizard. The plot on the far right shows a similar spectrum produced by a standard bench top analogue function generator. Noise harmonics are considerably lower for Signal Wizard. In the table, THD measurements are given for several spot sine wave frequencies (2 kHz, 3 kHz and 5 kHz), for Signal Wizard and the analogue instrument. The statistics confirm that at each frequency, the performance of Signal Wizard using the interpolation method is superior to that of the analogue function generator.