1Overview
The Model 845-M is a wideband low phase noise synthesizer operating up to 20 GHz. It delivers milli-Hz frequency resolution and runs from a high-stability internal reference that can be phase-locked to a programmable external source. Control is over USB and LAN using the SCPI 1999 command set, and the module ships with BNC's SigGen GUI software package.
Everything runs from a single external 6 V DC supply, so the 845-M drops into bench, rack, and embedded systems without a bulky mains front end. Order it as a single channel module or, as the 845-M-X, as a two-channel unit in a 1U rackmount chassis.
2Key Features
- Low phase noise across the full 10 MHz to 20 GHz span.
- Fast switching at 180 µs, dropping to 25 µs with option FS.
- Wideband DC frequency modulation for chirp and analog FM work.
- Internal OCXO reference with a programmable external reference input.
- Single 6 V DC supply and a small footprint for embedded integration.
- Milli-Hz resolution at 0.001 Hz steps.
3Frequency & Output Power
The 845-M covers 10 MHz to 20 GHz continuously with 0.001 Hz resolution and 0.1 ppm accuracy. Output power reaches +23 dBm, enough to drive mixers and frequency converters directly in many local-oscillator roles.
| Parameter | Specification |
|---|---|
| Frequency range | 10 MHz to 20 GHz (0.01 to 20 GHz) |
| Frequency resolution | 0.001 Hz |
| Frequency accuracy | 0.1 ppm |
| Output power | +23 dBm |
4Phase Noise & Spectral Purity
Low phase noise is the defining trait of the 845-M. Close-in performance reaches −118 dBc/Hz at a 1 kHz offset, with the noise floor falling toward the wideband limit at larger offsets.
| Offset | Phase Noise |
|---|---|
| 1 kHz | −118 dBc/Hz |
| 20 kHz | −128 dBc/Hz |
| Wideband noise floor | −150 dBc/Hz |
5Modulation
The 845-M supports pulse modulation from internal or external sources, frequency modulation, phase modulation, and chirp. Wideband DC-coupled frequency modulation makes it well suited to fast FM and linear chirp generation.
| Mode | Specification |
|---|---|
| Pulse | Internal and external |
| Frequency modulation | Wideband, DC-coupled |
| Phase modulation | Supported |
| Chirp | Supported |
6Frequency Switching & Sweep
Standard switching speed is 180 µs. Option FS lowers that to 25 µs for agile hopping and fast test sequencing. The module runs both frequency sweeps and list sweeps for automated coverage of a band.
| Parameter | Specification |
|---|---|
| Switching speed | 180 µs (25 µs with option FS) |
| Sweep modes | List, frequency |
7Specifications
| Parameter | Specification |
|---|---|
| Channels | 1 (845-M) or 2 (845-M-X) |
| Frequency range | 10 MHz to 20 GHz |
| Frequency resolution | 0.001 Hz |
| Frequency accuracy | 0.1 ppm |
| Output power | +23 dBm |
| Switching speed | 180 µs (25 µs with option FS) |
| Phase noise @ 1 kHz | −118 dBc/Hz |
| Phase noise @ 20 kHz | −128 dBc/Hz |
| Wideband noise | −150 dBc/Hz |
| Modulation | Pulse (internal/external), FM, phase, chirp |
| Sweeps | List, frequency |
| Remote control | Ethernet, USB; SCPI v1999 |
| Reference | Internal OCXO; programmable external reference |
| Dimensions (845-M) | 8.27″ × 4.13″ × 2.36″ [210 × 105 × 60 mm] |
| Weight (845-M) | 2.1 lbs [0.95 kg] |
| Dimensions (845-M with FS) | 10.62″ × 4.13″ × 2.36″ [270 × 105 × 60 mm] |
| Weight (845-M with FS) | 2.2 lbs [1 kg] |
| Dimensions (845-M-X) | 16.8″ × 18.1″ × 1.7″ [426 × 460 × 43 mm] |
| Weight (845-M-X) | 10 lbs [4.5 kg] |
| Power supply | External 6 V DC |
| Software | BNC SigGen GUI included |
8Interfaces & Form Factor
The 845-M controls over Ethernet and USB using SCPI v1999, so it slots into existing automated test frameworks with little custom code. The internal OCXO holds frequency, and a programmable external reference input lets you phase-lock the module to a system clock.
The single-channel module measures 8.27″ × 4.13″ × 2.36″ and weighs about 2.1 lbs. The two-channel 845-M-X ships in a 1U 19″ rackmount chassis. All variants run from a single external 6 V DC supply.
9Options & Configurations
| Option | Description |
|---|---|
| FS | Ultra-fast switching speed (25 µs) |
| 1URM | 19″ 1U rackmount enclosure |
| VREF | Variable external reference input (1–250 MHz, 1 MHz steps) |
| GPIB | GPIB interface (requires option 1URM) |
| P/N 7134 | Spare power supply |
| P/N 7145 | 19″ 2U 845-M / 865-M dual rackmount kit |
| 845-M-X | Two-channel version in 1U rackmount |
10Applications
- Automated test equipment (ATE)
- Local oscillator for frequency converters
- Telecom and SatCom systems
- Embedded systems
- OEM microwave signal source
11Ordering
Order the base 845-M as a single-channel module or the 845-M-X for two channels in a 1U rackmount. Add option FS for 25 µs switching, VREF for a variable external reference, and 1URM or GPIB for rack and bus integration. For configuration help, pricing, or a quotation, contact Berkeley Nucleonics at info@berkeleynucleonics.com or 800-234-7858.