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Product Data Sheet

Model 855B Multi-Channel RF and Microwave Signal Generators

A 1U rackmount, ultra-low phase noise, phase-coherent multi-channel signal generator with ultra-fast switching, high output power, and very stable phase coherence across all channels.

Model 855B · 300 kHz to 6, 12, 20, 33 and 40 GHz · up to 4 channels · Data Sheet
Berkeley Nucleonics Model 855B multi-channel signal generator

1Overview

The Model 855B is a phase-coherent, multi-channel, high output power, ultra-fast switching and ultra-low phase noise signal generator with a frequency range from 300 kHz to 6, 12, 20, 33 or 40 GHz. It suits a wide range of applications where good signal quality, accurate and wide output power ranges, and very stable phase coherence among all channels are required. Excellent phase noise is combined with good spurious, harmonic rejection and optionally leading-edge switching speed of 25 µs.

A high-stability OCXO reference provides excellent frequency accuracy and stability. The generator accepts a wide range of external references including the commonly used 10 and 100 MHz, and a flexible reference choice in the range of 1 to 250 MHz for customer- or system-specific reference frequencies. The Model 855B also features a pair of BNC-specific high-frequency CLK ports (one input and one output) that enable excellent phase synchronization among the outputs from multiple 855B modules.

The Model 855B comes in a standard 19 inch 1U (up to 4 channels) rack-mountable module form. It can be controlled by a PC-based GUI software and offers USB, LAN or GPIB interfaces, each using the SCPI 1999 command set. A customer-supplied API or programming examples for Matlab, Labview, C++ and other tools make control implementation straightforward.

2Key Features

  • Very low phase noise.
  • Industry lowest phase drift.
  • Ultra-fast switching.
  • Phase-coherent switching option.
  • Multi-channel phase-coherent outputs.
  • Variable external clock reference output.

Applications

  • Radar simulation.
  • Quantum computing.
  • High volume automated testing.
  • Phased array antenna / beamforming.
  • Electronic warfare.
  • SatCom R&D.

3Frequency & Output Power

Frequency Parameters / Range

ParameterMinMaxNote
Frequency Range
855B-06300 kHz6 GHz
855B-12300 kHz12 GHz
855B-20300 kHz20 GHz
855B-33300 kHz33 GHz
855B-40300 kHz40 GHz
Resolution<0.001 Hz (typical)
Phase Adjustment Range0 deg360 degIndividually adjustable per channel
Phase Resolution0.1 deg (typical)

Level Performance

Low frequency response of the 855B-20 from 100 kHz to 100 MHz
Figure 6: Low frequency response 855B-20 (100 kHz to 100 MHz).

Output power level varies by frequency band. With option PE4 an electrical step attenuator extends the floor to -80 dBm (855B-06/12/20) or -50 dBm (855B-33/40).

Output Power LevelMinMaxNote
Output Power Level 855B/06/12/20/33/40G
< 100 MHz-20 dBm+20 dBm
100 MHz to 6 GHz-20 dBm+25 dBm
6 GHz to 18 GHz-20 dBm+23 dBm
18 GHz to 20 GHz-20 dBm+20 dBm
20 GHz to 40 GHz-20 dBm+18 dBm
Output Power Level 855B-06/12/20GOption PE4
10 MHz to 12 GHz-80 dBm+20 dBm
12 GHz to 15 GHz-80 dBm+18 dBm
15 GHz to 20 GHz-80 dBm+15 dBm
Output Power Level 855B-33/40Option PE4
10 MHz to 20 GHz-50 dBm+19 dBm
20 to 33 GHz-50 dBm+16 dBm
33 to 40 GHz-50 dBm+15 dBm
Power Resolution0.01 dB (typical)
Thermal Drift0.015 dB/°C (typical)
Maximum output power of the 855B-20 with and without option PE4
Figure 4: Maximum output power 855B-20 with and without option PE4.
Maximum output power of the 855B-40 with and without option PE4
Figure 5: Maximum output power 855B-40 with and without option PE4.

Relative Power Error (0.1 dB Step)

Values in parentheses are typical.

FrequencyMin Power to -50 dBm (PE4)-50 to -20 dBm (PE4)-20 to +15 dBm+15 dBm to Max Power
300 kHz to 20 GHz(< 0.1 dB)0.5 dB (< 0.1 dB)0.5 dB (< 0.1 dB)(< 0.1 dB)
20 to 26 GHzN/A(< 0.1 dB)(< 0.1 dB)(< 0.1 dB)
26 to 40 GHzN/A(<0.1 dB)3(< 0.1 dB)(< 0.1 dB)

Power Level Uncertainty

Values in parentheses are typical.

FrequencyMin Power to -50 dBm (PE4)-50 to -15 dBm (PE4)-15 to +15 dBm+15 dBm to Max Power
< 6 GHz(4 dB)1.2 dB0.8 dB (0.25 dB)1.2 dB
6 to 12 GHz(4 dB)1.3 dB0.9 dB (0.3 dB)1.3 dB
12 to 26 GHz(4 dB)2.0 dB1.0 dB (0.3 dB)2.0 dB
26 to 40 GHzN/A2.3 dB1.2 dB (0.4 dB)2.3 dB

2 Applies to devices with Serial Number >= ###-#########-0888 and to devices with Option PL.   3 Applies to the range -45 dBm to -20 dBm.

Level error of the 855B-40 from 300 kHz to 40 GHz
Figure 7: Level error (300 kHz to 40 GHz, 855B-40).
Level linearity deviation in dB versus power set
Figure 8: Level linearity.
Level linearity with option PE4, power sweep 0.1 dB step
Figure 9: Level linearity with option PE4.

Reverse Power Protection and VSWR

ParameterTypicalMaxNote
Reverse Power Protection
DC Voltage±10 V
RF Power26 dBm
Output Impedance50 Ohms
VSWR
< 15 GHz1.31.5
15 to 35 GHz1.61.8
> 35 GHz1.92.2
VSWR versus frequency from 0 to 40000 MHz
Figure 10: VSWR.

4Phase Noise & Spectral Purity

Phase Noise

SSB phase noise at maximum output power, ALC off. Option LN improves close-in performance at each carrier frequency.

Parameter (SSB Phase Noise)TypicalMaxNote
SSB Phase noise at 1 GHzSee plots/tables. Max output power, ALC Off
At 10 Hz from carrier-87 dBc/Hz-76 dBc/Hz
At 10 Hz from carrier-98 dBc/Hz-86 dBc/HzOption LN
At 1 kHz from carrier-130 dBc/Hz-125 dBc/Hz
At 100 kHz from carrier-145 dBc/Hz-140 dBc/Hz
SSB Phase Noise at 4 GHzMax output power, ALC Off
At 10 Hz from carrier-74 dBc/Hz-68 dBc/Hz
At 10 Hz from carrier-85 dBc/Hz-74 dBc/HzOption LN
At 1 kHz from carrier-116 dBc/Hz-111 dBc/Hz1
At 100 kHz from carrier-136 dBc/Hz-131 dBc/Hz
SSB Phase noise at 10 GHzMax output power, ALC Off
At 10 Hz from carrier-67 dBc/Hz-60 dBc/Hz
At 10 Hz from carrier-77 dBc/Hz-66 dBc/HzOption LN
At 1 kHz from carrier-108 dBc/Hz-103 dBc/Hz
At 100 kHz from carrier-127 dBc/Hz-122 dBc/Hz

1 With option PHS, the phase noise for offsets >= 100 Hz at frequencies between 1.1 GHz and 10 GHz is typically 10 dB higher.

SSB phase noise with and without option LN at 1 GHz and maximum output power
Figure 1: Phase noise with and without option LN (at 1 GHz and max. output power).
SSB phase noise without option LN at maximum output power for 1, 5, 10, 20, 30 and 40 GHz carriers
Figure 2: Phase noise without option LN (at max. output power).

Spectral Purity

ParameterTypicalMaxNote
Harmonics 6, 12, 20GAt +5 dBm output power
50 to 200 MHz-30 dBc-20 dBc
200 to 600 MHz-35 dBc-25 dBc
600 MHz to 6 GHz-40 dBc-30 dBc
6 to 30 GHz-35 dBc-25 dBc
Harmonics 33, 40G
50 to 200 MHz-30 dBc-20 dBc
200 MHz to 12 GHz-35 dBc-30 dBc
12 to 20 GHz-30 dBc-20 dBc
> 20 GHz-25 dBc
Sub-Harmonics
< 5 GHz-75 dBc-70 dBc
5 to 20 GHz-70 dBc-65 dBc
> 20 GHz-55 dBc
Non-Harmonic Spurious> 10 kHz offset
< 1.2 GHz-90 dBc-60 dBc
1.2 to 2.5 GHz-92 dBc-60 dBc
2.5 to 5 GHz-87 dBc-60 dBc
5 to 10 GHz-80 dBc-60 dBc
10 to 20 GHz-75 dBc-50 dBc
20 to 40 GHz-67 dBc
855B-40 second harmonic power versus frequency
Figure 3: 855B / 40G harmonic performance.

5Modulation

The 855B provides pulse modulation, including an internal pulse generator and pulse pattern modulation with staggered PRF. Option MOD adds amplitude, frequency, and phase modulation.

Pulse Modulation

855B-40 25 ns pulse modulation at a 40 GHz carrier frequency
Figure 16: 855B-40 25 ns pulse modulation, 40 GHz carrier frequency.
ParameterMinTypicalMaxNote
Modulation SourceInternal / External
External input amplitudeTTL
Pulse rise/fall time10 ns
On/off ratio
90 dB80 dBf < 6.5 GHz
80 dB70 dB6.5 to 18 GHz
75 dB> 18 GHz (power > +10 dBm)
Pulse overshoot10%
Pulse delay20 ns
Pulse polarityNormal, InverseSelectable

Internal pulse generator

ParameterMinTypicalMaxNote
Repetition frequency (PRF)0.1 Hz50 MHz= 1/T
Duty cycle1% to 99% in 1% stepswithin specified minimum pulse width
Pulse Pattern Modulation & Staggered PRFusing internal pattern generator
Pulse width25 ns20 s
Programmable pattern length265536
Duty cycle0.05%99.95%
Pulse width resolution5 ns
Pulse period (T) accuracy0.00005xT + 3ns
Pulse width accuracy0.00005xT + 5ns
Pulse jitter2 ns5 ns
Polarityselectable

Amplitude Modulation (Option MOD)

ParameterMinTypicalMaxNote
Modulation SourceInternal
Modulation Depth0%90%
Deviation Accuracy2%4%1 kHz rate, 30% depth, 10 dBm
Deviation Resolution1%
Distortion (THD)1%1 kHz rate, 30% depth, 10 dBm
Modulation rate0.1 Hz20 kHz
Modulation waveformsSine

Frequency Modulation (Option MOD)

ParameterMinTypicalMaxNote
Modulation SourceInternal
Modulation Frequency deviation (peak)N · 200 MHz< 1.25 GHz (N=1); 1.25 to 2.5 GHz (N=0.125); 2.5 to 5 GHz (N=0.25); 5 to 10 GHz (N=0.5); 10 to 20 GHz (N=1); 20 to 40 GHz (N=2)
Deviation Accuracy0.50%2%
Distortion (THD)< 1%1 kHz rate, 10 kHz deviation
Modulation rate0.1 Hz80 kHz
Modulation waveformsSine

Phase Modulation (Option MOD)

ParameterMinTypicalMaxNote
Modulation SourceInternal
Phase deviation (peak)0300 · N · rad
Deviation Accuracy0.50%2%
Modulation rate0.1 Hz80 kHz
Modulation waveformsSine
Distortion (THD)< 1%1 kHz rate & N x rad deviation

6Switching, Sweep & Reference

Switching Speed

ParameterTypicalNote
Switching SpeedAfter SCPI command received
CW Mode1.5 ms
Sweep/List mode500 µs
25 µsOption FS

Sweeping Capability

ParameterMinTypicalMaxNote
Sweep ParametersFrequency, power, phase, list
Sweep typeLinear, logarithmic, random
Step time (tstep)500 µs19998 sStandard
f < 31.8 GHz, fstep < 2.2 GHz25 µsOption FS (1, 2 channels)4 in band
50 µsOption FS (3, 4 channels)4 in band
<=70 µsOption FS cross band
f < 31.8 GHz, fstep >= 2.2 GHz30 µsOption NEC (1, 2 channels)4 in band
50 µsOption NEC (3, 4 channels)4 in band
<=70 µsOption NEC cross band
f >= 31.8 GHz, fstep < 0.55 GHz100 µsOption NEC (1 to 4 channels)4
30 µsOption NEC (1, 2 channels)4 in band
50 µsOption NEC (3, 4 channels)4 in band
<= 70 µsOption NEC cross band
f >= 31.8 GHz, fstep >= 0.55 GHz500 µsOption NEC (1 to 4 channels)
Dwell time (tdwell)15 µs9999 s
Off time (toff)15 µs9999 s
Time resolution5 ns
Timing delay (Tde)50 ns
Transient time (Tinv)25 µs
Timing accuracy per point5 ns
Number of points210000Per channel
Sweep timing diagram showing TRIG IN, TRIG OUT signal valid and RF valid with t-step, t-de, t-inv and t-val intervals
Sweep timing: TRIG IN, TRIG OUT (signal valid) and RF valid, showing τstep, τde, τinv and τval.

Frequency Reference

ParameterTypicalNote
Internal Reference Frequency100 MHz
Internal Reference Frequency10 MHzOption LN
Temperature stability 0 to 50 degC±100 ppb
Temperature stability 0 to 50 degC±20 ppbOption LN
Aging 1st year1000 ppb
Aging 1st year30 ppbOption LN
Aging 1st year20 ppbOption LN+
Aging per day5 ppbAfter 30 days operations
Aging per day0.5 ppbOption LN
Warm-up time5 min
Output of internal reference10 MHz / 100 MHzREF OUT port, selectable
Output of High Frequency Clock3 GHzCLK OUT port
Output power (high phase synchronous mode)0 dBm10 MHz, 3 GHz
Output power9 dBm100 MHz
Output impedance50 Ohms
Bypass Internal Reference Input100, 1000 MHz*Options LN/LN+ are bypassed
Phase Lock to External Reference10 MHz integer MHz (1 MHz to 250 MHz)REF IN port, Option VREF. *Options LN/LN+ are bypassed
High Frequency Clock Input (Bypass Internal Reference)3 GHzCLK IN port, high phase synchronous mode
Reference input level: 10 MHz or 1-250 MHz or 3 GHz0 dBm (-5 to +10 dBm)
Reference input level: 100, 1000 MHz+5 to +13 dBm
Lock Range: 10 MHz or 1-250 MHz±1.5 ppm
Lock Range: 100 MHz100 ppm
Reference input impedance50 Ohms

Trigger (TRIG IN)

ParameterMinTypicalMaxNote
Trigger TypesContinuous; Single (point); Gated; Gated Direction
Trigger SourceExternal; Bus (LAN, USB)
Trigger ModesContinuous free run; Trigger and run; Reset and Run
Trigger Latency5 ns
Trigger Uncertainty10 ns
External Trigger delay50 ns40 ssettable
External delay resolution5 ns
Trigger modulo1255Execute only on Nth trigger event
Trigger PolarityRising; Falling
External trigger input threshold0.85 V0.9 V0.95 VTTL Compatible
External trigger input voltage range-0.5 V+5.5 VTTL Compatible
External trigger input hysteresis60 mV

Multi-Purpose Output (FUNC OUT)

Output is TRIG OUT at the rear panel. Multifunction generator: sine, triangle, square wave.

ParameterMinTypicalMaxNote
Frequency range1 Hz3 MHzSine
Frequency range1 Hz1 MHzTriangle
Frequency range50 kHzSquare
Frequency resolution0.1 Hz
Output voltage amplitude peak-peak10 mV2 VSine, triangle
Output voltage amplitude peak-peak5 VSquare (CMOS output)
Harmonic Distortion1%< 100 kHz, 1 Vpp
Output impedance50 Ohms / CMOSSine, triangle / Square wave
Video output (of internal pulse modulator)CMOS; Period 30 ns to 50 s; Pulse width 15 ns to 50 s; RF delay 10 ns
Trigger out modesTrigger on sweep start; Trigger on each point; Signal ValidSynchronization mode for multiple sources

4 In band / cross band as noted per option and channel count.

6bChannel-to-Channel Performance

ParameterMinTypicalNote
Isolation
< 3 GHz90 dB
3 to 6.5 GHz70 dB80 dB
> 6 GHz> 60 dB
300 kHz to 40 GHz80 dB> 90 dBOption HI, see plot
Relative Phase Stability between Channels0.096 ps3 mrad at 5 GHz over 5 hours
Relative Phase Stability between Synchronized Modules0.160 ps5 mrad at 5 GHz over 5 hours
Phase-Coherent Switching
Phase mismatch at outputs15 ps
Channel-to-channel isolation with option HI for CH1-CH2, CH1-CH3 and CH1-CH4
Figure 11: Channel-to-channel isolation with option HI (channel under test: channel 1 at frequency f, power 10 dBm; channels 2, 3 and 4 at f + 9 MHz, power 10 dBm; measurement made on channel 1 at f + 9 MHz).
Channel-to-channel phase stability under different test conditions over 10 hours
Figure 12: Channel-to-channel phase stability under different test conditions.
855B-20 time domain channel-to-channel phase error at 10 GHz over 12 hours
Figure 13: 855B-20 typical time domain channel-to-channel phase error at 10 GHz.
855B-20 time domain channel-to-channel phase error at 20 GHz over 12 hours
Figure 14: 855B-20 typical time domain channel-to-channel phase error at 20 GHz.
855B-40 time domain channel-to-channel phase error at 38 GHz over 10 hours
Figure 15: 855B-40 typical time domain channel-to-channel phase error at 38 GHz.

7General Characteristics

ParameterSpecification
Remote programming interfacesEthernet 100BaseT LAN; USB 2.0 device; GPIB (IEEE-488.2, 1987) with listen and talk (Option GPIB)
Control languageSCPI Version 1999.0
Power requirements100 - 240 VAC, 50 or 60 Hz, 160W maximum (80W + 20W per channel)
EnvironmentalLevels similar to MIL-PRF-28800F Class ¾
Safety / EMCComplies with applicable Safety and EMC regulations and directives
Weight21 lbs [≤ 10.0 kg] net
Dimensions, 19” 1U enclosure (855B-06/12/20)1.7 in H x 16.8 in W x 18.3 in L [44 mm H x 426 mm W x 465 mm]
Dimensions, 19” 1U enclosure (855B-33/40)1.7 in H x 16.8 in W x 19.1 in L [44 mm H x 426 mm W x 485 mm]
Dimensions, 19” 1U HI enclosure1.7 in H x 17.3 in W x 18.5 in L [44 mm H x 440 mm W x 470 mm L]
Definitions. Specifications describe the warranted performance of the instrument for 23 ±5 °C after a 30-minute warm-up period (unless otherwise stated). Min/Max: parameter range guaranteed by product design and/or production tested, including guard-bands. Typical: expected mean values, not warranted performance.

8Connectors & Form Factor

The 855B is controlled through USB, LAN or GPIB, all using the SCPI 1999 command set. Dedicated 3 GHz CLK I/O ports synchronize multiple units, so phase-coherent test setups can scale across multiple modules. Up to 4 channels fit a standard 19 inch 1U enclosure. A high-isolation chassis is available with option HI.

Connectors (Front)

Model 855-R four-channel front panel with power, remote and RF output connectors
Model 855-R four-channel front panel: power switch, status LEDs, and RF OUT 1 to 4.
  • Power Switch.
  • LED Indicator: Power ON; Remote; RF ON (per channel).
  • RF Outputs: 855B-33, 40: K (2.92 mm) female; 855B-06, 12, 20: SMA female.
  • External pulse modulation inputs: BNC female.

Connectors (Rear)

Model 855B rear panel with SYNC, CLK, TRIG, REF, GPIB, LAN, USB and power connectors
Rear panel: SYNC IN/OUT, CLK IN/OUT, TRIG OUT/IN, REF OUT/IN, GPIB, LAN, USB, fuse and AC power.
  • Unit-to-unit synchronization signal input (SYNC IN): SMA female.5
  • Unit-to-unit synchronization signal output (SYNC OUT): SMA female.5
  • High Stability Reference input (CLK IN, 3 GHz): SMA female.
  • High Stability Reference output (CLK OUT, 3 GHz): SMA female.
  • Trigger output (TRIG OUT): BNC female.
  • Trigger input (TRIG IN): BNC female.
  • Reference input (REF IN): BNC female.
  • GPIB: IEEE-488.2, 1987 with listen and talk (optional).
  • LAN connection: RJ-45.
  • USB 2.0 device.
  • FUSE (3.15 A).
  • 100-240V AC power plug.

5 Allows to extend option PHS over multiple units (unreleased).

Casings Standard 19” 1U

Model 855B standard 19 inch 1U rack-mount casing, four-channel front panel with power, remote and per-channel PULSE and RF OUT connectors
Standard 19” 1U casing (up to 4 channels), front panel with power switch, POWER and REMOTE indicators, and per-channel PULSE and RF OUT connectors.

High Isolation Casing 19” 1U (Option HI, rack mount kit included)

Model 855B high isolation 19 inch 1U casing (Option HI) front panel with remote indicator and per-channel PULSE and RF OUT connectors
High Isolation 19” 1U casing (Option HI), rack mount kit included.

9Options & Configurations

OptionDescription
LNEnhanced close in phase noise and frequency stability
LN+Option LN with improved long term frequency stability
PE4-12Electrical step attenuator (6 & 12 GHz version)
PE4-20Electrical step attenuator (20 GHz version)
PE4-40Electrical step attenuator (33 & 40 GHz version)
PHSPhase coherent switching
FSUltra-fast switching speed
MODAmplitude, frequency, phase modulations added
VREFFlexible external reference frequency support in range 1 to 250 MHz
GPIBGPIB interface
FLASHMicroSD card slot for removable SD memory
HIHigh isolation 19” 1U casing (highly improved channel-to-channel isolation)
IECIEC 17025 Calibration with Certificate
RetrofitApplies when options are back-ordered

10Applications

  • Radar simulation and phased-array antenna or beamforming test.
  • Quantum computing.
  • High-volume automated testing.
  • Electronic warfare.
  • Satellite communications R&D.

11Ordering

Specify the frequency variant (855B-6 through 855B-40), channel count, chassis size, and options when requesting a quote. For configuration help, pricing, or a demonstration, contact Berkeley Nucleonics.

ContactDetail
Emailinfo@berkeleynucleonics.com
Phone800-234-7858
Quote / demoberkeleynucleonics.com/get-quote
Configuration note. Channel count, chassis size, phase-noise grade, and per-output frequency ranges are configurable. Confirm the exact build and all performance figures against the released Model 855B datasheet (v1.74) before ordering.