Stanford Research SG386 6 GHz Signal Generator

The Stanford Research SG386 is a 6 GHz RF signal generator delivering precision frequency synthesis, low phase noise, and versatile modulation in a single instrument. Built on Rational Approximation Frequency Synthesis architecture, it generates signals from 950 kHz to 6.075 GHz with 1 µHz resolution and phase noise of −116 dBc/Hz at 20 kHz offset (1 GHz carrier). Frequency switching completes in less than 8 ms to within 1 ppm accuracy.

The instrument supports AM, FM, phase modulation, and pulse modulation with internal sources (sine, ramp, saw, square, pulse, noise) and external modulation inputs. AM modulation reaches 0 to 100% depth with 0.1% resolution. Output from the front-panel N-type connector ranges from +16.5 dBm to −110 dBm, equivalent to 1 Vrms to 0.707 µVrms into 50 Ω. A secondary BNC output delivers DC to 62.5 MHz signals at amplitudes from 1.00 Vrms to 0.001 Vrms with ±5% accuracy and ±1.5 VDC offset capability.

Spurious content remains below −70 dBc typical (within 10 kHz offset), while harmonics measure less than −25 dBc at output levels below +7 dBm. An optional frequency doubler (Opt. 02) extends maximum output to 8.10 GHz. Fast frequency switching, excellent spectral purity, and flexible modulation options position this generator for RF/microwave component testing, communication system validation, and wideband signal applications where signal integrity is critical.

– Technical Specifications

• Frequency Range: 950 kHz to 6.075 GHz (standard); up to 8.10 GHz with Opt. 02
• Frequency Resolution: 1 µHz
• Frequency Switching Speed: < 8 ms (to within 1 ppm)
• Phase Noise (SSB): −116 dBc/Hz at 20 kHz offset, 1 GHz carrier
• Spurious Content: < −70 dBc typical (< 10 kHz offset); harmonics < −25 dBc at < +7 dBm output
• N-Type Output Power: +16.5 dBm to −110 dBm (1 Vrms to 0.707 µVrms into 50 Ω)
• BNC Output Frequency Range: DC to 62.5 MHz
• BNC Output Amplitude: 1.00 Vrms to 0.001 Vrms; ±5% accuracy
• BNC Output Offset: ±1.5 VDC (5 mV resolution)
• Output Impedance: 50 Ω

– Key Features

• AM modulation 0–100% with 0.1% resolution
• FM, phase modulation, and pulse modulation modes
• Internal modulation waveforms: sine, ramp, saw, square, pulse, noise
• External modulation input: ±1 V for full deviation (AM, FM, ΦM)
• Fast switching performance with 1 µHz tuning resolution
• Low phase noise scaling 6 dB/octave to alternate carrier frequencies

– Typical Applications

• RF and microwave component characterization
• Communication system testing and validation
• Signal integrity assessment in receiver chains
• Modulated signal generation for transceiver development

– Compatibility & Integration

N-type and BNC front-panel connectors support standard 50 Ω coaxial cables and unterminated loads.