The Model 855 series is a phase coherent multi-output fast switching and low phase noise signal generator with a frequency range from 10 MHz to 6.2, 12.5, or 20.0 GHz. The 855 is ideally suited for a variety of applications where good signal quality and a wide, accurate output power range are required. Excellent phase noise is combined with spurious and harmonic rejection. A high-stability OCXO reference provides excellent frequency accuracy and stability. The generator accepts external 10, 100, or 1000 MHz references.