354

The Sonoma Instrument 354 is a broadband preamplifier covering 10 kHz to 3 GHz (-3 dB), designed for EMI measurements, antenna signal amplification, and general-purpose RF signal amplification applications where high linearity and a generous maximum input level are the primary requirements. With a gain of 19 ±1 dB at 1 GHz, gain flatness of ±0.5 dB from 500 kHz to 2 GHz, and a third order intercept point of +28 dBm at 300 MHz, it trades some gain against the Sonoma 317 in exchange for a significantly higher maximum input for linear operation of approximately ±190 mV — making it well-suited for environments where signal levels at the input are less predictable or where overload resistance is more important than maximum sensitivity.

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 -44 dB at 0 dBm output from 10 MHz to 1.5 GHz, input return loss of 13 dB typical, output return loss of 10 dB typical, and reverse isolation of 22 dB typical — all from 10 MHz to 3 GHz. The equivalent input noise voltage is 0.78 nV/√Hz including 0.45 nV/√Hz from a 50 Ω source. The input damage level is ±1V DC, -4 dBm RF, and ±200 mV pulse — the most tolerant pulse input rating in the Sonoma 3XX series. The unit is AC coupled with 50 Ω impedance and uses Type N connectors at both input and output.

Time domain performance includes a rise time of 110 psec and group delay variation of ±30 psec from 45 MHz to 3 GHz. 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.