Vector Signal Generator
A signal generator that produces the protocol, not a recording of it. Framing, coding, scrambling and signalling are generated live in FPGA fabric from real modem cores — so the waveform stays standards-compliant indefinitely, responds to configuration changes immediately, and needs no PC in the loop.
- 0
- Host PCs required in normal operation
- ∞
- Generation length — live, not replayed from memory
- 500 MHz
- Instantaneous modulation bandwidth
- All
- Supported waveforms included, no option keys
For when you need a capable generator, not a general-purpose one
General-purpose vector generators are excellent instruments and we are not trying to replace them. This exists for the cases where they are awkward: when you need a genuinely standards-compliant stream running for days, when the waveform option you need costs more than the instrument, or when the test rig cannot have a Windows PC in it.
Protocol-accurate, not replayed
Most generators play a pre-computed IQ file. That is fine until you need a long run without repetition, a changing MODCOD, real signalling fields, or a payload that varies. We generate the protocol continuously, so all of those are just configuration.
Genuinely standalone
Power and an antenna port. Configuration lives on the instrument, boots with it and survives a power cycle. It runs in an anechoic chamber, on a vehicle, in a rack at a remote site — anywhere a host PC would be a liability.
No option-key economics
Every waveform the platform supports is enabled. We do not sell the same hardware five times with different licence files, because we find the practice indefensible.
Generated as the standard defines them
Each waveform below is produced by the corresponding AlfaRF modem core running in the instrument — the same RTL we license, with the same conformance testing behind it. That is what makes "standards-compliant" a checkable claim rather than a marketing one.
| Waveform | Generated by | Coverage |
|---|---|---|
| DVB-S2 / S2X | ALF-RF-S2X-TX |
All 128 MODCODs, VCM/ACM, VL-SNR, roll-off 5–35 %, to 500 Mbaud |
| 5G NR downlink | ALF-RF-NR-PHY |
FR1 and FR2, PDSCH/PDCCH/PBCH/SSB, numerologies μ = 0–3 |
| CCSDS telemetry | ALF-RF-CCSDS |
131.0-B framing, GMSK and filtered OQPSK, PN ranging |
| CPM / SOQPSK telemetry | ALF-RF-CPM |
IRIG-106 Chapter 2 profiles, full and partial response |
| Generic QAM / APSK | ALF-RF-QAM |
16-QAM to 256-APSK, user framing, 1 ksym/s – 250 Msym/s |
| Generic PSK | ALF-RF-PSK |
BPSK, QPSK, OQPSK, 8-PSK and 16-PSK, user framing, to 300 Msym/s |
| Arbitrary IQ | — | User-supplied samples, streamed or resident, with looping |
What "capable" means here
- Live protocol state MODCOD, resource allocation, framing parameters and payload can change on a frame boundary while transmitting, driven by a script or an external trigger. A replayed file cannot do this — it is the single biggest practical difference between the two approaches.
- Real payloads PRBS, a fixed pattern, a file, or a live transport stream fed in over Ethernet and carried inside the generated waveform. That last one is what turns the instrument into a signal source for an end-to-end system test.
- Calibrated impairments Optional injection of AWGN at a calibrated Es/N0, frequency offset, phase noise against a mask, and IQ imbalance — enough to characterise a receiver's tolerance without a separate channel emulator. For full propagation modelling, pair it with an ALF-CE.
- Multi-carrier scenarios Several independently configured carriers generated concurrently and summed — a wanted signal plus its adjacent-channel neighbours, or a populated transponder, from one instrument.
- Deterministic timing Frame and burst timing are locked to the reference input, so the generator can act as the timing master for a TDD device under test, with a trigger output aligned to a chosen frame boundary.
ALF-SG series
Two platform sizes plus a digital-only variant for integration into an existing RF chain. The waveform set is identical across all three.
| Model | Output | Modulation bandwidth | Carriers | Typical use |
|---|---|---|---|---|
ALF-SG-1000 |
RF, 70 MHz – 6 GHz | Up to 200 MHz | Up to 4 | Receiver development and conformance testing |
ALF-SG-2000 |
RF, 70 MHz – 6 GHz | Up to 500 MHz | Up to 16 | Wideband, multi-carrier and transponder scenarios |
ALF-SG-D |
Digital IQ only | Up to 500 MHz | Up to 16 | Integration behind your own up-converter |
Signal specifications
| Frequency range | 70 MHz – 6 GHz (model dependent) |
|---|---|
| Modulation bandwidth | Up to 500 MHz instantaneous |
| Output power | −120 to +10 dBm, 0.1 dB steps |
| Level accuracy | ±0.5 dB |
| Residual EVM | < 0.5 % at 64-QAM |
| ACLR | > 70 dB (5G NR 100 MHz carrier) |
| Harmonics | < −55 dBc |
| Frequency accuracy | Reference-locked, OCXO standard |
| Generation length | Unlimited — continuous, not replayed |
Control and integration
| Standalone operation | Full configuration from the front panel |
|---|---|
| Configuration storage | On-instrument, persists across power cycles |
| Remote control | SCPI over LAN, REST API, Python bindings |
| Payload input | Internal PRBS/pattern, file, or live stream over Ethernet |
| Triggering | External trigger in, frame-aligned trigger out |
| Reference | 10 MHz / PPS in and out, IEEE 1588 option |
| Digital IQ | JESD204C or 10/25 GbE streaming (ALF-SG-D) |
| Form factor | 2U rack mount, or benchtop |
| Warranty | 12 months, extendable |
Which waveform, and how long does it need to run?
Those two answers usually settle whether this is the right instrument for you. We will say so either way.