317

The Sonoma Instrument 317 is a high-gain broadband preamplifier covering 10 kHz to 2.5 GHz (-3 dB), designed for EMI measurements, antenna signal amplification, and general-purpose RF signal amplification applications requiring high gain and excellent linearity across a wide frequency range. With a gain of 38 ±1.5 dB at 1 GHz — 18 dB more than the Sonoma 330 and 6 dB more than the Sonoma 310 — and gain flatness of ±0.75 dB from 500 kHz to 2 GHz, it delivers consistent high-gain performance from below the AM broadcast band through the lower microwave range in a single instrument.

Key specifications include a noise figure of 4.8 dB from 10 MHz to 2 GHz, an output at 1 dB gain compression of +15 dBm (3.5 Vp-p) from 10 MHz to 2.5 GHz, harmonic distortion of -45 dBc typical at 0 dBm output, and a third order intercept point of +28 dBm at 300 MHz. Input return loss is 14 dB typical from 10 MHz to 1.5 GHz and 8 dB typical from 1.5 to 2.5 GHz. Output return loss is 12 dB typical across the full range. Reverse isolation is 44 dB from 10 MHz to 2.5 GHz. The equivalent input noise voltage is 0.78 nV/√Hz including 0.45 nV/√Hz from a 50 Ω source. The maximum input for linear operation is approximately ±22 mV, with an input damage level of ±1V DC, -22 dBm RF, and ±25 mV pulse. The unit is AC coupled with 50 Ω impedance and uses Type N connectors at both input and output.

Time domain performance includes a typical rise time of 120 psec and group delay variation of ±30 psec from 45 MHz to 2.5 GHz — making it well-suited for wideband pulse and transient measurements in addition to CW EMI applications. The unit is mains-powered at 100, 120, 220, or 240V AC / 50–60 Hz at 20 VA. Operating temperature range is 0 to +55°C up to an altitude of 15,240 ft / 5,000 m. Physical dimensions are 91 × 109 × 183 mm (H × W × D) — identical in form factor to all other Sonoma 3XX series amplifiers — with a net weight of 1.5 kg.