Stanford Research SG396 6 GHz Vector Generator

The Stanford Research Systems SG396 is a 6 GHz vector signal generator engineered for RF and microwave development requiring analog and vector modulation in a single platform. It combines Rational Approximation Frequency Synthesis (RAFS) with dual arbitrary waveform generators to deliver spur-free outputs, 1 μHz frequency resolution, and -116 dBc/Hz phase noise at 1 GHz. The instrument supports ASK, FSK, MSK, PSK, QAM, and VSB modulation with factory presets for GSM, EDGE, W-CDMA, APCO-25, DECT, NADC, PDC, ATSC-DTV, and TETRA standards.

Frequency switching occurs in under 8 ms to within 1 ppm. Dual baseband generators operate at 125 MHz with symbol rates to 6 MHz, while 300 MHz modulation bandwidth accommodates advanced I/Q applications. Digitally controlled attenuation spans 156 steps to -130 dB, with up to +25 dB gain and calibrated power control via a 40,000-element memory matrix.

Standard and optional rubidium timebases support frequency stability of 1 × 10⁻¹¹ (1 s Allan variance). RF output via Type N connector (above 950 kHz) and BNC for DC to 62.5 MHz signals. Direct AWGN injection capability supports noise-injection testing workflows.

Technical Specifications

• Frequency range: DC to 6.075 GHz


• Frequency resolution: 1 μHz


• Frequency synthesis: Rational Approximation Frequency Synthesis (RAFS)


• Frequency switching time: 40 dBc (>35 dBc above 4 GHz)


• Modulation bandwidth: 300 MHz


• I/Q inputs: 50 Ω, ±0.5 V


• Dual arbitrary waveform generators: 125 MHz operation, up to 6 MHz symbol rate


• AM modulation: 0 to 100% (0.1% resolution)


• AM distortion: <1% (fC < 62.5 MHz, fM = 1 kHz); 62.5 MHz, fM = 1 kHz)


• FM frequency deviation: 0.1 Hz minimum; frequency-dependent maximum

Key Features

• Spur-free synthesis via RAFS topology


• Vector modulation: ASK, FSK, MSK, PSK, QAM, VSB, and custom I/Q


• PSK derivatives: BPSK, QPSK, OQPSK, DQPSK, π/4DQPSK, 8PSK, 16PSK, 3π/8 8PSK


• QAM variants: 4, 16, 32, and higher orders


• VSB variants: 8VSB, 16VSB


• Standard modulation presets: GSM, EDGE, W-CDMA, APCO-25, DECT, NADC, PDC, ATSC-DTV, TETRA


• Direct AWGN injection into signal path


• Calibrated power control with 40,000-element memory matrix


• Ovenized or optional rubidium timebase

Typical Applications

• Wireless communications development and testing


• Radar system characterization


• Satellite communications signal generation


• Modulation validation across multiple standards


• Noise injection and receiver stress testing

Compatibility & Integration

• RF output: Type N connector (≥950 kHz)


• Baseband output: BNC (DC to 62.5 MHz)


• External modulation: ±0.5 V I/Q inputs at 50 Ω impedance