Siglent SSG3021X 9 kHz ~ 2.1 GHz Signal Generator
SIGLENT’S SSG3021X signal generators hase a frequency range of 9 kHz to 2.1 GHz. The SSG3021X provides normal analog modulation such as AM, FM, and PM. It also provide pulse modulation and pulse train generator
Siglent has discontinued the SSG3021X and it can no longer be ordered. Its successor, the SSG3021X Plus, covers the same 9 kHz to 2.1 GHz at the same list price, with lower phase noise and an optional OCXO reference. This page stays online as a reference for owners; options, service and calibration for the SSG3021X continue.
SSG3021X — what it is, and what replaces it
The SSG3021X is the 2.1 GHz model of the SSG3000X series: a 9 kHz to 2.1 GHz RF source with a level range of −110 to +20 dBm, AM, FM, PM and pulse modulation, and −110 dBc/Hz phase noise at 1 GHz.
It has been the entry point to Siglent’s RF generators since 2019, on benches for receiver testing, as an LO or clock source, in teaching labs and in production test. With the launch of the SSG3000X Plus on 30 September 2026 Siglent stopped building it; the SSG3021X Plus takes over in the same enclosure and at the same price.
Below: an honest side-by-side of the two instruments, what remains available for an SSG3021X you already own, and the full specification as Siglent published it.
The successor
The SSG3021X Plus is the direct replacement. If you were going to add the 3.2 GHz upgrade later, the SSG3032X Plus costs less than a 2.1 GHz unit plus the upgrade key.
9 kHz – 2.1 GHz. Same range, level and price as the SSG3021X; −117 dBc/Hz phase noise at 1 GHz, OCXO option.
9 kHz – 3.2 GHz. The same instrument with the full frequency range from the factory.
All four models, the six options and the full specification on one page.
SSG3021X and SSG3021X Plus, side by side
Taken row by row from the two datasheets. Most of the instrument is unchanged; the phase noise and the reference improve, and three figures are specified differently — they are marked, not hidden.
| Parameter | SSG3021X (end of life) | SSG3021X Plus | |
|---|---|---|---|
| Frequency range, CW | 9 kHz – 2.1 GHz | 9 kHz – 2.1 GHz | SAME |
| Level setting range | −110 to +20 dBm (from 1 MHz) | −110 to +20 dBm (from 1 MHz) | SAME |
| Specified level range | −110 to +13 dBm (from 1 MHz) · to +7 dBm at 9–100 kHz | −110 to +13 dBm (from 1 MHz) · to +5 dBm at 9–100 kHz | DIFFERS |
| Level error | ≤ 0.7 dB, 100 kHz and up (≤ 0.5 dB typ.) | ≤ 0.7 dB, 100 kHz and up (≤ 0.5 dB typ.) | SAME |
| SSB phase noise, 1 GHz, 20 kHz offset | −110 dBc/Hz (typ.) | −117 dBc/Hz (typ.) | IMPROVED |
| SSB phase noise, 100 MHz, 20 kHz offset | −118 dBc/Hz (typ.) | −121 dBc/Hz (typ.) | IMPROVED |
| Frequency reference | < 0.2 ppm initial, < 0.5 ppm first year · no OCXO available | Same as standard · optional 10M_OCXO_L: ±100 ppb initial, 50 ppb / year | IMPROVED |
| Harmonics / sub-harmonics | < −30 dBc / < −45 dBc | < −30 dBc / < −45 dBc | SAME |
| Non-harmonics, offset > 10 kHz | < −63 dBc to 1.5 GHz · < −75 dBc above 1.5 GHz | < −63 dBc | DIFFERS |
| Analog modulation | AM, FM, PM · internal, external, internal + external | AM, FM, PM · internal, external, internal + external | SAME |
| Pulse modulation | Single and double pulse · width from 20 ns · rise/fall < 50 ns | Single and double pulse · width from 20 ns · rise/fall < 50 ns | SAME |
| Pulse on/off ratio | > 70 dBc, 1 MHz – 2.1 GHz | > 63 dBc (1–250 MHz) · > 68 dBc (250 MHz – 2.1 GHz) | DIFFERS |
| Pulse train option | SSG3000X-PT | SSG3000X Plus-PT | SAME |
| 3.2 GHz upgrade key | SSG3000X-21BW32 | SSG3000X Plus-21BW32 | SAME |
| Interfaces | USB host, USB device (USBTMC), LAN · GPIB by adapter | USB host, USB device (USBTMC), LAN · GPIB by adapter | SAME |
| Size and weight | 338 × 113 × 369 mm · 4.84 kg | 338 × 113 × 369 mm · 4.84 kg | SAME |
| List price | €1,999 | €1,999 | SAME |
Sources: SSG3000X datasheet DS0803X EN01D and SSG3000X Plus datasheet EN01A. Typical values are not warranted. List prices exclude VAT.
If you own an SSG3021X
End of life means no new units — not the end of support.
Repair and warranty
Nothing changes for units already delivered. Warranty claims and repairs go through the RMA request page, as before.
Calibration
We keep calibrating the SSG3000X series. See ISO / DKD calibration for what each certificate covers.
Manuals and firmware
User manual, programming guide, datasheet and the latest firmware remain in the downloads centre.
Software keys
Keys for the SSG3000X remain available and are generated for your serial number. The SSG3000X licence page lists them all.
Options that fit the SSG3021X
| SSG3000X-PT | Pulse train generator (software key) | €819 |
| SSG3000X-21BW32 | Upgrade 2.1 GHz → 3.2 GHz (software key) | €1,999 |
| SSG-RMK | 19-inch rack mount kit | €159 |
| USB-GPIB | USB–GPIB adapter | €135 |
The SSG3000X Plus has its own key codes (SSG3000X Plus-PT, SSG3000X Plus-21BW32). They are not interchangeable with the keys above. Send the serial number of your SSG3021X with the order; the key is generated for that instrument.
SSG3021X specification
| Status | End of life — discontinued by Siglent. Successor: the SSG3021X Plus |
| Frequency range | CW 9 kHz – 2.1 GHz · 0.01 Hz resolution |
| Setting time | < 5 ms (typ.) ALC on · < 10 ms (typ.) ALC off (S&H) |
| Frequency reference | 10 MHz · < 0.2 ppm initial · < 0.5 ppm first year, 3 ppm / 20 years · 10 MHz in (−5 to +10 dBm) and out |
| Level setting range | −110 to +9 dBm (9–100 kHz) · −110 to +15 dBm (100 kHz–1 MHz) · −110 to +20 dBm (1 MHz–2.1 GHz) · 0.01 dB resolution |
| Specified level range | −110 to +7 dBm (9–100 kHz) · −110 to +10 dBm (100 kHz–1 MHz) · −110 to +13 dBm (1 MHz–2.1 GHz) |
| Level error (ALC on, 20–30 °C) | ≤ 0.7 dB from 100 kHz, +13 to −90 dBm (≤ 0.5 dB typ.) · ≤ 1.1 dB to −105 dBm · ≤ 1.8 dB to −110 dBm |
| Harmonics / sub-harmonics | < −30 dBc / < −45 dBc (CW, level ≤ +13 dBm, above 1 MHz) |
| Non-harmonics | < −63 dBc (1 MHz–1.5 GHz) · < −75 dBc (1.5–2.1 GHz), offset > 10 kHz |
| SSB phase noise, 20 kHz offset | −118 dBc/Hz at 100 MHz · −110 dBc/Hz at 1 GHz (typ.) |
| Analog modulation | AM 0–100 % · FM to N × 1 MHz deviation · PM to N × 5 rad · source internal, external or both |
| LF generator | Sine 0.1 Hz–1 MHz; square, triangle, saw-tooth to 20 kHz · 1 mVpp–3 Vpp into 50 Ω |
| Pulse modulation | Single and double pulse · on/off > 70 dBc · rise/fall < 50 ns · period 40 ns–300 s, width 20 ns–300 s, 10 ns resolution |
| Pulse train (option SSG3000X-PT) | 1–2,047 pulses · 1–65,535 repetitions per pulse · on/off time 20 ns–300 s |
| Sweep | Frequency and level · step (2–65,535 points) or list (to 500 points) · dwell 10 ms–100 s |
| Front panel | RF out N female 50 Ω · LF out BNC 50 Ω |
| Rear panel | Trig in/out · Ext mod in · Pulse in/out · 10 MHz in / out · Signal valid |
| Interfaces | USB host · USB device (USBTMC) · LAN (VXI-11, socket, telnet) · GPIB with the USB-GPIB adapter |
| Display | 5-inch capacitive touchscreen, 800 × 480 · web-browser remote control |
| Power | 100–240 V, 50/60 Hz · 35 W |
| Size / weight | 338 × 113 × 369 mm · 4.84 kg |
| Options | SSG3000X-PT · SSG3000X-21BW32 · SSG-RMK · USB-GPIB |
From Siglent’s SSG3000X datasheet (DS0803X EN01D). N is the band factor from the datasheet: 0.5 from 1 to 250 MHz and from 1 to 2 GHz, 0.125 from 250 to 500 MHz, 0.25 from 500 MHz to 1 GHz, 1 above 2 GHz.
Questions about the SSG3021X
Is the SSG3021X still available?
No. The SSG3021X has reached end of life and can no longer be ordered. Siglent replaced it with the SSG3021X Plus, which covers the same 9 kHz to 2.1 GHz at the same list price. This page stays online as a reference for owners.
What replaces the SSG3021X?
The SSG3021X Plus. Same frequency range, output level, modulation, connections and enclosure; phase noise at 1 GHz improves from −110 to −117 dBc/Hz (typical, 20 kHz offset) and an oven-controlled reference (10M_OCXO_L) can be fitted at the factory for the first time.
Is the SSG3021X Plus identical in every other respect?
Almost. Three datasheet figures differ: the pulse on/off ratio is specified at > 63 dBc below 250 MHz and > 68 dBc above (the SSG3021X: > 70 dBc), non-harmonics at < −63 dBc across the range (the SSG3021X: < −75 dBc above 1.5 GHz), and the specified level at 9–100 kHz reaches +5 instead of +7 dBm. If your test depends on one of these, tell us the frequency and we will check it with Siglent before you order.
Can I still buy options for my SSG3021X?
Yes. The pulse train key SSG3000X-PT, the 3.2 GHz upgrade key SSG3000X-21BW32, the SSG-RMK rack kit and the USB-GPIB adapter are all in our shop. Software keys are generated for the serial number of your instrument.
Do the SSG3000X Plus keys work on my SSG3021X?
No. The Plus keys (SSG3000X Plus-PT, SSG3000X Plus-21BW32) are separate order codes for the Plus instruments. For an SSG3021X order the SSG3000X keys listed on this page.
Is my SSG3021X still supported?
Yes. The warranty on units already delivered is unaffected, repair and calibration run through our RMA request page as before, and the manuals and firmware stay in the downloads centre.
Can the SSG3021X Plus replace an SSG3021X in a rack or test system?
Mechanically, yes: the enclosure is the same 338 × 113 × 369 mm, so it takes the same SSG-RMK rack kit, and the front and rear connections are in the same family (USB, LAN, 10 MHz in/out, trigger, pulse, external modulation). For remote-controlled systems compare the two programming guides, or send us your command list and we will check it.
Replacing or extending an SSG3021X?
Tell us what the generator does on your bench or in your test system. We will confirm whether the SSG3021X Plus is a straight swap for it, and quote it with the options you use today.