Signal Generator with Frequency Resolution down to 1 µHz

10 August 2011 - SRS (Stanford Research Systems) has introduced the SG384, a DC to 4 GHz signal generator that uses a unique and innovative architecture to deliver frequency resolution down to 1 µHz.

A technique known as rational approximation frequency synthesis enables the new instrument to deliver ultra-high frequency resolution, excellent phase noise, and versatile modulation capabilities at a fraction of the cost of competing designs.

The SG384 offers a wide variety of modulation capabilities including amplitude modulation (AM), frequency modulation (FM), phase modulation (ØM) and pulse modulation. There is an internal modulation source as well as an external modulation input. The internal modulation source produces sine, ramp, saw, square and noise waveforms. An external modulation signal may be applied to the rear-panel modulation input.

The generator comes with an oven-controlled crystal oscillator (OCXO) timebase. The timebase uses a third-overtone stress-compensated 10 MHz resonator in a thermostatically controlled oven. The timebase provides very high stability of 0.002 ppm low phase noise and very low aging. An optional rubidium oscillator may be added to reduce frequency aging still further and to improve temperature stability.

Optional I/Q inputs allow I and Q baseband signals to modulate carriers from 400 MHz to 4.05 GHz. This option also allows the I/Q modulator to be driven by an internal noise generator with adjustable amplitude and bandwidth. Rear-panel outputs allow the noise source to be viewed or used for other purposes.

Remote operation of the generator is supported with GPIB, RS-232 and Ethernet interfaces. All instrument functions can be controlled and read over any of the interfaces. Up to nine complete instrument configurations can be saved in non-volatile memory.

The SG384 is available in the UK through TTid (Thurlby Thandar instrument distribution) who represent all engineering test and measurement products from SRS.