Siglent SSA5000-P5 pre-amplifier 9 kHz to 26.5 GHz (software license)
Licence for the internal pre-amplifier of the SSA5085A: about 20 dB of gain ahead of the first mixer, which lowers the displayed noise floor by 10 to 18 dB above 1 MHz.
SSA5000-P5 — pre-amplifier, 9 kHz to 26.5 GHz
Licence for the internal pre-amplifier of the SSA5085A: about 20 dB of gain ahead of the first mixer, which lowers the displayed noise floor by 10 to 18 dB above 1 MHz.
A spectrum analyser cannot show a signal that is weaker than its own noise. The pre-amplifier adds gain before the first mixer, so the analyser’s noise is divided down relative to the signal: the data-sheet noise floor at 1 GHz moves from −144 to −159 dBm/Hz. Siglent lists the pre-amplifier for the SSA5000A as a licence — P5 for the 26.5 GHz SSA5085A, P3 for the 13.6 GHz SSA5083A.
What this option does
What it does
Enables the internal pre-amplifier (20 dB nominal) over 9 kHz to 26.5 GHz. It is switched on and off in the Amplitude menu, and the analyser accounts for its gain in the level readout.
What you use it for
Low-level work: spurious and harmonics close to the noise floor, off-air signals, near-field probing, and noise measurements, where the analyser’s own noise would otherwise set the result.
In practice
With a 1 Hz resolution bandwidth, a −150 dBm spur at 2 GHz sits below the −140 dBm noise floor with the pre-amplifier off. Switched on, the floor drops to −158 dBm and the spur stands 8 dB clear.
⚠ Check your analyser first. The pre-amplifier may already be active on your unit. Open System → System and read the option information, or try the pre-amplifier in the Amplitude menu: if “PA” appears, you do not need this key. Send us the serial number if you are unsure. The pre-amplifier trades range for sensitivity — the +23 dBm input range and the distortion figures in the data sheet are given with it off.
What the pre-amplifier changes
Lower noise floor
10 to 18 dB lower displayed average noise level above 1 MHz (data sheet, RBW 1 Hz).
Best case
−153 dBm/Hz, −165 typical, from 1 to 10 MHz — the series’ headline figure is a pre-amplifier-on figure.
Gain
20 dB nominal, specified by Siglent from 100 kHz to 26.5 GHz.
On when needed
Switched in the Amplitude menu; the “PA” icon shows the state.
Accuracy
Absolute amplitude accuracy ±0.5 dB plus frequency response with the pre-amplifier on, ±0.4 dB with it off.
Large signals
Gain ahead of the mixer lowers the level at which the analyser compresses. Switch it off for strong signals.
Noise measurements
Noise-figure mode switches the pre-amplifier on automatically, according to Siglent’s application note.
By key
A software licence in Siglent’s price list; nothing is fitted.
Specification
From the SSA5000A data sheet (EN02A) and user manual.
| Pre-amplifier off | Pre-amplifier on | |
|---|---|---|
| DANL 100 kHz–1 MHz | −130 dBm/Hz, −143 typical | −135 dBm/Hz, −148 typical |
| DANL 1–10 MHz | −143 dBm/Hz, −148 typical | −153 dBm/Hz, −165 typical |
| DANL 10 MHz–1.22 GHz | −144 dBm/Hz, −148 typical | −159 dBm/Hz, −163 typical |
| DANL 1.22–3.15 GHz | −140 dBm/Hz, −144 typical | −158 dBm/Hz, −162 typical |
| DANL 3.15–7.22 GHz | −137 dBm/Hz, −141 typical | −154 dBm/Hz, −158 typical |
| DANL 7.22–13.6 GHz | −136 dBm/Hz, −140 typical | −154 dBm/Hz, −158 typical |
| DANL 13.6–18.9 GHz | −134 dBm/Hz, −140 typical | −151 dBm/Hz, −155 typical |
| DANL 18.9–24.2 GHz | −132 dBm/Hz, −137 typical | −148 dBm/Hz, −152 typical |
| DANL 24.2–26.5 GHz | −124 dBm/Hz, −134 typical | −142 dBm/Hz, −149 typical |
| Absolute amplitude accuracy | ±0.4 dB + frequency response | ±0.5 dB + frequency response |
| Gain | — | 20 dB nominal |
| Licence range | 9 kHz to 26.5 GHz (SSA5085A) | |
| Conditions | 20–30 °C, 0 dB attenuation, RBW 1 Hz, sample detector, trace average > 50 | |
Compatibility and activation
SSA5000-P5 is the licence for the SSA5085A. For the SSA5083A, Siglent lists SSA5000-P3.
Supplied as a licence key issued against the analyser’s serial number — nothing to fit and nothing to return. Enter it under System → System → Load Option, or load the licence file from internal memory or a USB stick; the option is active after a restart.
Goes with
Questions about SSA5000-P5
Is the pre-amplifier not already in my analyser?
It may be active already. Siglent’s ordering information lists the pre-amplifier as an option, but check System → System for the installed options, or switch it on under Amplitude. If “PA” appears, you do not need this licence.
How much does the noise floor improve?
By the data sheet: 15 dB at 1 GHz (−144 to −159 dBm/Hz), 17 to 18 dB from 1.22 to 13.6 GHz, and 16 to 18 dB above 13.6 GHz.
When should I leave it off?
Whenever the signal is strong. The pre-amplifier raises the level at the mixer by 20 dB, so distortion products and compression appear at lower input levels. Siglent specifies TOI, harmonic distortion and the maximum input level with it off.
Which licence fits my model?
SSA5000-P3 covers 9 kHz to 13.6 GHz for the SSA5083A; SSA5000-P5 covers 9 kHz to 26.5 GHz for the SSA5085A.
How is the licence delivered?
Supplied as a licence key issued against the analyser’s serial number — nothing to fit and nothing to return. Enter it under System → System → Load Option, or load the licence file from internal memory or a USB stick; the option is active after a restart. Add the analyser’s serial number to your order, or send it to us afterwards.
Can I return a licence?
Software licences and activation keys are delivered electronically and are excluded from the 14-day EU return right once the key has been issued. If you are unsure, ask us first.
Planning an SSA5000A measurement?
Tell us the signal, the frequency range and what you need to measure. We will confirm the model and the options you need before you order.