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Product Data Sheet

Model 835 Microwave/RF Signal Generator

9 kHz to 6 GHz RF / Microwave Signal Generator. A very compact, low-noise, fast-switching analog signal source with OCXO-stabilized phase noise, micro-Hertz frequency resolution, and a full modulation suite in a 12 watt package.

Datasheet V230, dc-50604202. Specifications reconciled against the published Model 835 datasheet. Items not stated in the source are marked (verify).
Berkeley Nucleonics Model 835 RF signal generator

1Overview

Model 835 front panel with lit touch screen display showing frequency, power and phase
Model 835 front panel with touch screen display (9 kHz to 6 GHz).

The Model 835 models comprise a set of very compact, portable analog signal generator models from 9 kHz up to 6100 MHz. A combination of good signal purity, fast switching speed and wide dynamic range makes these units useful for a variety of applications.

The Model 835 is a series of low-noise and fast-switching analogue signal generators covering a frequency range from 9 kHz up to 4.0, and 6.1 GHz, respectively. It provides full RF signal generator capabilities including OCXO-stabilized low phase-noise signal with micro-Hz frequency resolution, wide and accurately levelled output power range, extensive modulation capabilities, and fast switching. It is targeted for a wide range of applications where a high-quality analogue signal is mandatory, offering an alternative to expensive high-end RF signal generators, where small size and excellent RF performance at an attractive cost is required.

The very compact and rugged design operates at very low DC power consumption (only 12 watts), with minor heat dissipation and not requiring a noisy fan. This gives the Model 835 a great advantage in laboratories or production test facilities. The low power design allows the use of optional internal battery modules which make it a truly portable instrument, ideally suited for field testing, installation, and maintenance.

The Model 835 supports various standard interfaces such as USB (USBTMC), LAN (VXI-11), or GPIB and extensive API with programming examples are available.

Available options: PE3 (power level extension to accurately level below -120 dBm), B3 (internal rechargeable battery module), AVIO (avionics modulation such as VOR/ILS), 1URM (19" rack-mountable 1U enclosure), and EB6 (external power bank adapter cable with voltage converter for 12 to 25 V supply).
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, with guard-bands for statistical distribution, measurement uncertainty, and environmental conditions. Typical: expected mean values, not warranted performance.

2Key Features

  • High output power, low phase noise.
  • Comprehensive AM, low-distortion.
  • Wideband DC-FM, and high-speed pulse modulation.
  • Powerful trigger and sweeping modes.
  • Portable battery operation.

3Frequency Parameters / Range

ParameterMinTypicalMaxNote
Frequency Range9 kHz4 GHz
6 GHz		835-4
835-6
Resolution0.001 Hz
Phase Resolution0.1 deg
Settling Time20 µs
20 µs		100 µs
200 µs		<= SN xx-xxx2xxxxx-xxxx
>= SN xx-xxx3xxxxx-xxxx
Frequency update rate
List/sweep mode		400 µs400 µstime from receipt of SCPI command
firmware
Total Jitter68 fs RMS10 Hz to 1 MHz BW
Reference frequency input8 MHz200 MHzUser programmable
Reference input level-5 dBm0 dBm+13 dBm
Lock Range+/- 1.0 ppm
Reference input impedance50 Ω
Internal reference frequency output10 MHz
Initial accuracy of internal reference±40 ppbcalibrated at 23 ± 3 °C at time of calibration
Temperature stability (0 to 50 degC)±100 ppb
Aging 1st year0.5 ppm
Aging per day (after 30 days operations)5 ppb
Warm-Up time5 min
Output of internal reference+0 dBm50 Ω

4Phase Noise

Model 835 measured SSB phase noise at 3 GHz and 6 GHz
Figure 1: Phase Noise Performance (3 and 6 GHz).
ParameterMinTypicalMaxNote
SSB Phase noise
At 20 kHz from carrier-130 dBc/Hz-128 dBc/HzSee measured phase noise plots

5Level Performance

Typical maximum output power versus frequency, without Option PE3
Figure 2: Typical Maximum Output Power (without Option PE3).
ParameterMinTypicalMaxNote
Power LevelSee plots on page 8
Without Option PE3-30 dBm+18 dBm
+17 dBm		>50 MHz & <6 GHz
<= 50 MHz
With Option PE3-120 dBm+10 dBm
+10 dBm		>50 MHz & <6 GHz
<= 50 MHz
Resolution0.01 dB
Level Uncertainty0.3 dB
0.5 dB
0.8 dB		< 0.8 dB
< 1.3 dB		-20 to + 10 dBm
-80 to -20 dBm
< -80 dBm
Typical maximum output power versus frequency, with Option PE3
Figure 3: Typical Maximum Output Power (with option PE3).

Two leveling paths are available. The standard instrument levels from -30 dBm to +18 dBm above 50 MHz. Option PE3 extends accurate leveling below -120 dBm for receiver sensitivity testing.

6Reverse Power Protection and VSWR

ParameterMinTypicalMaxNote
Reverse Power Protection
DC Voltage30 V
RF Power36 dBm
Output Impedance50 Ω
VSWR1.5
1.7		1.8
2.0		< 3 GHz
> 3 GHz

7Spectral Purity

2nd and 3rd harmonic performance at +10 dBm versus frequency
Figure 4: Harmonic Performance at +10 dBm.
ParameterMinTypicalMaxNote
Spectral Purity
Output Harmonics
> 3.7 GHz
Sub-harmonics		-40 dBc

-80 dBc		-30 dBc
-50 dBc
-70 dBc		Pout = +10 dBm

Option FILT
Non-harmonic spurious
< 1 MHz
1 MHz to 5.8 GHz
5.8 GHz to 6.1 GHz		-70 dBc
-65 dBc
-60 dBc		-60 dBc
-55 dBc
-50 dBc		Pout = +10 dBm
Residual FM @ 1 GHz3 Hz

12 Hz		0.3 kHz to 3 kHz, weighted (ITU-T)
0.03 kHz to 23 kHz
Harmonic performance with Option FILT versus frequency
Figure 5: Harmonic Performance with option FILT.

Option FILT adds harmonic filtering that reduces the second and third harmonic across the band, as shown in the filtered harmonic plot.

8Sweeping Capability

Sweeps can be performed with combined internal or external AM/FM/PM/Pulse modulation running. With modulation enabled, the minimum step time increases to 2 ms.

Frequency Sweep

Sweep type: linear, logarithmic, random.

ParameterMinTypicalMaxNote
Step time (tstop)400 µs19998 s
Dwell time (tdwell)50 µs9999 s
Off-time (incl. transient time) (toff)0 / 50 µs9999 s
Timing accuracy per point1 µs

Generalized List Sweep

Allows individual setting of frequency, power, dwell-time, and off-time for each point.

ParameterMinTypicalMaxNote
List size220.000
Step time (tstep)200 µs19998 s
Dwell time (tdwell)50 µs9999 s
Off-time (incl. transient time) (toff)0 / 50 µs9999 s
Time resolution0.1 µs
Timing accuracy per point1 µs

9Modulation Capabilities

All modulation types (FM, PM, AM, and pulse modulation) may be simultaneously enabled except: FM and phase modulation cannot be combined. For example, AM and FM can run concurrently and will modulate the output RF.

Pulse Modulation

ParameterMinTypicalMaxNote
On/Off ratio70 dB
Repetition FrequencyDC33 MHz
Pulse width30 ns
50 µs		20 s
20 s		ALC hold
ALC on
Pulse rise/fall time25 ns
Pulse trains length (pulses)24192
Video crosstalk-40 dB
External input threshold0.85 V0.9 V0.95 VTTL compatible
External input voltage range-0.5 V+5.5 VTTL compatible
External input hysteresis60 mV
Delay (to RF)20 ns40 ns

Frequency Modulation

ParameterMinTypicalMaxNote
Maximum Frequency deviation (peak)0
0		0.05·f
N·200 MHz		< 0.25 GHz
0.25 GHz to 0.75 GHz (N=0.125)
0.75 GHz to 1.5 GHz (N=0.25)
1.5 GHz to 3 GHz (N=0.5)
> 3 GHz to 6.1 GHz (N=1)
Modulation waveformsSine, triangle, FSK
Modulation Rate1 Hz/DC800 kHz-3dB frequency response. Max. phase deviation degrades above 20 kHz modulation rate
External input sensitivity< N · 100 MHz for 1 Vppsettable in AC mode; discrete values in DC mode
Total harmonic distortion< 1%1 kHz rate & N · 100 kHz deviation

Frequency Chirps (linear ramp, up/down)

ParameterMinTypicalMaxNote
Span10%
Dwell time (tchirp)10 ns60 s
Slope100 MHz/µs
Total duration of finite repeated chirps (tchirp * repetitions)64.1 s
Number of frequencies20.000

Phase Modulation

ParameterMinTypicalMaxNote
Phase deviation (peak)0N·80 rad
Modulation rate1 Hz800 kHz> -3dB frequency response
Modulation waveformsSine, triangle, FSK
External Input sensitivityN · 40 rad for 1 Vpp
Total Harmonic distortion< 1%1 kHz rate & N ·20 rad deviation

Amplitude Modulation

ParameterMinTypicalMaxNote
Modulation Rate10 Hz
10 Hz		20 kHz
50 kHz		applies for internal and external
>= SN xx-xxx5xxxxx-xxxx
Modulation Depth0%95%
Modulation WaveformsSine, triangle, square
Accuracy (f<10 MHz)1.3%2%f-carrier, modulation depth <80% & 1 kHz modulation rate, power 0 dBm
Distortion (f<10 MHz)1.6%3%
Accuracy (f>10 MHz)0.6%1.4%
Distortion (f>10 MHz)1%2%
External input sensitivityX% per 1 Vppsettable

10Avionics Modulation (Option AVIO)

Option AVIO adds dedicated avionics modulation such as VOR and ILS.

ILS

ParameterTypicalNote
Localizer RF frequency108 to 112 MHz
Nominal tone frequencies90 & 150 Hz
Frequency accuracy< 0.02 Hz
Centerline (in %)DDM: 0 ± 0.1; SDM: 40 ± 2.0
Fly left (in %)DDM: 15.5 ± 0.5; SDM: 40 ± 2.0
Fly right (in %)DDM: -15.5 ± 0.5; SDM: 40 ± 2.0
Flag (in %)DDM: 0 ± 0.1; SDM: 30 ± 2.0
Glide Path RF frequency328.6-335.4 MHz
Angle of Descent (in %)DDM: 0 ± 0.1; SDM: 80 ± 3.0
Fly up (in %)DDM: 17.5 ± 0.5; SDM: 80 ± 3.0
Fly down (in %)DDM: -17.5 ± 0.5; SDM: 80 ± 3.0
Flag (in %)DDM: 0 ± 0.1; SDM: 70 ± 2.5

VOR

ParameterTypicalNote
VOR RF frequency108 - 118 MHz
Subcarrier Frequency9960 ± 2.0 Hz
FM deviation480 Hz
AM tone30 ± 0.02 Hz
Bearing northTDM: 30 ±2.0 %; Phase: 180 ± 0.5 deg
Bearing southTDM: 30 ± 2.0 %; Phase: 90 ± 0.5 deg
Bearing EastTDM: 30 ± 2.0 %; Phase: 0 ± 0.5 deg
Bearing WestTDM: 30 ± 2.0 %; Phase: 270 ± 0.5 deg
Test 1TDM: 20 ± 1.5 %; Phase: 0 ± 0.5 deg
Test 2TDM: 40 ± 2.0 %; Phase: 0 ± 0.5 deg

11Multi-Purpose Output (FUNC OUT) and Trigger (TRIG IN)

Multi-Purpose Output (FUNC OUT)

Output in FUNC OUT at rear panel.

ParameterMinTypicalMaxNote
MULTIFUNCTION GENERATOR
Sine, triangle, square wave
Frequency range10 Hz
10 Hz
10 Hz		3 MHz
1 MHz
50 kHz		Sine
Triangle
square
Frequency resolution0.6 Hz
Output voltage amplitude peak-peak10 mV2 VSine, triangle; Square (CMOS output)
Harmonic Distortion1%< 100 kHz, 1 Vpp
Output impedance50 Ω
CMOS		Sine, triangle
Squarewave
VIDEO OUTPUT (of internal pulse modulator)
OutputCMOS
Period30 ns50 s
Pulse width15 ns50 s
RF delay10 ns
TRIGGER OUT (synchronization mode for multiple sources)
Modes		Trigger on sweep start; Trigger on each point
Trigger waveform pulse width100 ns

Trigger (TRIG IN)

Input is TRIG IN at rear panel.

ParameterMinTypicalMaxNote
Trigger TypesContinuous, single, gated, gated Direction
Trigger SourceRF key, external, bus (GPIB, LAN, USB)
Trigger ModesContinuous free run, trigger and run, reset and run
Trigger LatencyTbd
Trigger Uncertainty5 µs
External trigger delay50 µs40 s
External Delay resolution15 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

12Connectors

Front (with Touch Screen Display)

Model 835 front panel with touch screen display and RF output
Front panel: 1. RF output (N female), 2. Rotary knob.
  1. RF output N female
  2. Rotary knob

Rear

Model 835 rear panel connector layout
Rear panel connector layout (numbered callouts).
  1. Trigger input BNC female
  2. Function output BNC female
  3. External reference input BNC female
  4. Internal reference output BNC female
  5. FM/PM modulation input BNC female
  6. AM and Pulse modulation BNC female
  7. LAN connection RJ-45
  8. USB 2.0 device
  9. GPIB IEEE-488.2, 1987 with listen and talk (optional)
  10. DC Power plug (6V, 6 A)
  11. DC Power switch
  12. Ground screw
  13. Vent Holes: Air Intake.
  14. Vent Holes: Air Exhaust

13Ordering Information

Host ModelProduct / Description
8359 kHz – 4000 MHz Signal Generators
8359 kHz – 6100 MHz Signal Generators
835Option B3 Internal rechargeable battery module
835Option PE3 Mechanical step attenuator
835Option FILT Harmonic Filtering
835Option FLASH MicroSD card slot for removable SD memory
835Option GPIB GPIB interface
Option GPIB interface connector panel showing GPIB, USB A, USB B and LAN
835Option EB6 External power bank adapter cable with voltage converter for 12 to 25 V supply. Required input connector: Inner / outer diameter 2.1 / 5.5 mm
835Option AVIO Avionics modulation capability (VOR/ILS)
835Option 1URM 1U rack-mount module. Dimensions 1.7 in H x 16.8 in W x 18.1 in L (42 mm H x 426 mm W x 460 mm L)
Option 1URM 1U rack-mount module
835Option RM 19” 3 U rack-mount kit
835Option REAR Move output to the rear panel

14General Characteristics

ParameterSpecification
Remote Programming InterfacesEthernet 100BaseT LAN interface; USB 2.0 host & device; GPIB (IEEE-488.2, 1987) with listen and talk (optional)
Control languageSCPI Version 1999.0
Power requirements6 VDC; 20 W maximum
Mains adapter supplied100-240 VAC / 6 V 6.0 A DC out
Storage temperature range-40 to 70 °C
Operating temperature range0 to 45 °C
Operating and storage altitudeup to 15,000 feet
Safety / EMCCE markcomplies with applicable Safety and EMC regulations and directives
Weight6 lbs (≤2.5 kg) net, 8 lbs (≤ 4 kg) shipping
Dimensions (W x L x H), excluding connectors6.83 x 9.84 x 4.60 in [172 x 250 x 106 mm]
Dimensions (W x L x H), including connectors6.83 x 10.66 x 4.60 in [172 x 273 x 106 mm]
Recommended calibration cycle24 months
Compatibility languagesSupporting commonly used commands: Agilent Technologies N5181A MXG, Aeroflex, Rohde & Schwarz SMA and SML models

15Applications

Aerospace, satellite and RF application imagery for the Model 835 signal generator
Model 835 application contexts: aerospace, satellite communications, and RF test.
  • R&D Low Noise Signal Source
  • Production Testing
  • Service and Maintenance
  • Signal Simulation
  • Aerospace and Defense
  • Installation and Maintenance