1Overview
Berkeley Nucleonics has been designing precision RF and microwave instruments for more than 60 years. The Model 845 is a versatile single-channel signal generator that combines ultra-low phase noise, fast switching, and broad frequency coverage. It is a dependable bench source for engineers working across VLF through K-band, from low-noise local oscillators to radar receiver test.
Continuous tuning runs from 9 kHz to 26.5 GHz with sub-Hertz resolution. Three frequency builds let you buy only the range you need: the 845-12 reaches 12 GHz, the 845-20 reaches 20 GHz, and the 845-26 covers the full 26.5 GHz span. A touchscreen front panel, SCPI remote control, and optional battery operation make the instrument equally at home on the bench, in a rack, or in the field.
2Key Features
- Wide frequency range. Continuous coverage from 9 kHz to 26.5 GHz with 0.001 Hz resolution.
- Exceptional signal purity. Advanced fractional-N synthesis delivers low SSB phase noise.
- Accurate power control. Wide, leveled output power range with excellent linearity and 0.01 dB resolution.
- Fast, responsive operation. Quick frequency switching paired with an intuitive touchscreen display.
- Comprehensive modulation. AM, low-distortion wideband DC-FM, PM, and high-speed pulse modulation.
- Powerful trigger and sweep modes. List, frequency, and power sweeps for automated test.
- Customizable configurations. Modulation, interface, and enclosure options, including OEM board-level packaging.
- Portable battery operation. Optional external battery bank for field use.
3Frequency & Output Power
The Model 845 tunes continuously with 0.001 Hz resolution across the full range. Choose the build that matches your top frequency:
| Build | Frequency Range |
|---|---|
| 845-12 | 9 kHz to 12 GHz |
| 845-20 | 9 kHz to 20 GHz |
| 845-26 | 9 kHz to 26.5 GHz |
Standard leveled output power spans -20 to +15 dBm with 0.01 dB resolution. The PE3 mechanical step attenuator and HP high-output options together extend the range from -90 to +25 dBm, covering low-level receiver sensitivity work and higher-power drive in a single instrument.
4Phase Noise & Spectral Purity
SSB phase noise measured at 1 GHz CW:
| Offset from carrier | SSB phase noise (1 GHz CW) |
|---|---|
| 10 Hz | -80 dBc/Hz |
| 1 kHz | -117 dBc/Hz |
| 100 kHz | -128 dBc/Hz |
| 10 MHz | -150 dBc/Hz |
5Modulation
The Model 845 supports AM, FM, PM, pulse, and chirp modulation. The FM path is a low-distortion, wideband DC-FM design, and the pulse path is built for high-speed switching. Internal and external sources are available depending on configuration.
- AM for amplitude modulation test signals.
- FM low-distortion, wideband DC-coupled.
- PM phase modulation.
- Pulse high-speed pulse modulation.
- Chirp for swept-frequency stimulus.
6Frequency Switching & Sweep
Standard frequency switching speed is 400 microseconds. With the FS fast-switching option, switching drops to under 30 microseconds, suitable for fast frequency-hopping and agile test sequences. List, frequency, and power sweeps are supported for automated measurement.
| Parameter | Specification |
|---|---|
| Switching speed (standard) | 400 µs |
| Switching speed (option FS) | <30 µs |
| Sweep modes | List, Frequency, Power |
7Specifications
| Specification | Details |
|---|---|
| Frequency range | 845-12: 9 kHz to 12 GHz; 845-20: 9 kHz to 20 GHz; 845-26: 9 kHz to 26.5 GHz |
| Frequency resolution | 0.001 Hz |
| Number of channels | Single channel |
| Output power range | -20 to +15 dBm (-90 to +25 dBm with options PE3 and HP) |
| Power resolution | 0.01 dB |
| Phase noise (1 GHz CW) | 10 Hz: -80 dBc/Hz; 1 kHz: -117 dBc/Hz; 100 kHz: -128 dBc/Hz; 10 MHz: -150 dBc/Hz |
| Frequency switching speed | 400 µs (<30 µs with option FS) |
| Harmonics / spurious | (verify) |
| Modulation | AM, FM, PM, Pulse, Chirp |
| Vector modulation | (verify) |
| Sweeps / list | List, Frequency, Power |
| Reference input | Variable 1 MHz to 250 MHz |
| Reference output | 10 MHz / 100 MHz |
| Remote control / interfaces | SCPI v1999; Ethernet, USB; GPIB (with option GPIB) |
| Form factor | Benchtop with touchscreen; rackmount option |
| Dimensions (W x L x H) | 6.77 x 10.63 x 4.21 in (172 x 270 x 106 mm) |
| Weight | 5.5 lbs (2.5 kg) |
| Shipping dimensions | 18 x 12 x 9 in |
| Shipping weight | 10 lbs |
| Power requirements | (verify) |
8Interfaces & Form Factor
The Model 845 ships as a compact benchtop instrument with a touchscreen front panel. Remote control follows SCPI v1999 over Ethernet and USB, with GPIB available through the GPIB option. A variable reference input accepts 1 MHz to 250 MHz, and the reference output provides 10 MHz or 100 MHz for system synchronization.
For rack integration, the 1URM option provides a 19-inch 1U chassis, and the REAR option relocates the RF output to the rear panel. An OEM board-level package is available for embedded designs.
9Options & Configurations
| Option | Description |
|---|---|
| -HP | High output power |
| -FS | Fast switching (<30 µs) |
| -9K | 9 kHz frequency extension |
| -PE3 | Power extension down to -90 dBm (mechanical step attenuator) |
| -EB6 | External battery bank to 6V adapter |
| -FLASH | MicroSD card slot for removable SD memory |
| -GPIB | GPIB communication port |
| -1URM | 19-inch 1U rackmount chassis |
| -FILT | Improved harmonic filtering |
| -REAR | Move output to rear (requires -1URM) |
| -OEM | Board-level package |
Accessories
- 19-inch 3U single/dual rackmount kit for desktop chassis (P/N 7091)
- Spare power supply (P/N 7134)
- Ruggedized protective bumper (P/N 7144)
10Applications
- R&D low-noise signal source
- Product testing
- Service and maintenance
- Signal simulation
- Aerospace and defense
- Installation and maintenance
- Radar receiver testing
11Ordering
Specify the frequency build (845-12, 845-20, or 845-26) and append option codes as needed. For a configured quote or a demo unit, contact Berkeley Nucleonics.
| Model | Configuration |
|---|---|
| 845-12 | 9 kHz to 12 GHz, single channel |
| 845-20 | 9 kHz to 20 GHz, single channel |
| 845-26 | 9 kHz to 26.5 GHz, single channel |
Berkeley Nucleonics Corporation · info@berkeleynucleonics.com · 800-234-7858