Instruments-on-a-card designs, such as analyzers built into the PXI format, can provide compact building blocks for larger, multifunction systems. The model VMESG frequency synthesizer from Elcom Technologies is such a design, a 1-to-20-GHz source fabricated in a VME form factor. The source on a card incorporates several frequency synthesizer technologies to achieve its combination of fast switching speed and excellent spectral purity, including indirect-analog and direct-digital-synthesis (DDS) technologies. It includes a low-noise oven-controlled crystal oscillator (OCXO) reference and can achieve switching speed of 10 microseconds or less for a full-band frequency step. For additional information on the frequency synthesizer, click here.