Stanford SG390 Vector Signal Generators

Introducing the new SG390 Series Vector Signal Generators - high performance, affordable RF sources.

Three new RF Signal Generators, with carrier frequencies from DC to 2.025 GHz, 4.050 GHz and 6.075 GHz, support both analog and vector modulation. The instruments utilise a new RF synthesis technique which provides spur free outputs with low phase noise (-116 dBc/Hz at 1 GHz) and extraordinary frequency resolution (1 μHz at any frequency). Both analog modulation and vector baseband generators are included as standard features.

The instruments use an ovenised SC-cut oscillator as the standard timebase, providing a 100 fold improvement in the stability (and a 100 fold reduction in the in-close phase noise) compared to instruments which use a TCXO timebase.

The SG390 Series Signal Generators are based on a new frequency synthesis technique called Rational Approximation Frequency Synthesis (RAFS). RAFS uses small integer divisors in a conventional phase-locked loop (PLL) to synthesise a frequency that would be close to the desired frequency (typically within ±100 ppm) using the nominal PLL reference frequency. The PLL reference frequency, which is sourced by a voltage controlled crystal oscillator that is phase locked to a dithered direct digital synthesizer, is adjusted so that the PLL generates the exact frequency. Doing so provides a high phase comparison frequency (typically 25 MHz) yielding low phase noise while moving the PLL reference spurs far from the carrier where they can be easily removed. The end result is an agile RF source with low phase noise, essentially infinite frequency resolution, without the spurs of fractional-N synthesis or the cost of a YIG oscillator.

For further information please contact us or download the datasheet.