SIGNAL GENERATORS
Synthesized Signal Generator
Model 8645A
252 kHz to 2060 MHz frequency range
15 µsec frequency switching
Stand alone control of frequency agility
HP 8645A Agile Signal Generator
The HP 8645A Agile Signal Generator combines high performance with frequency agility for new fast-switching test requirements.
These capabilities are important for performance testing of such de-
vices as frequency agile radios and surveillance receivers. Besides extending traditional receiver testing to agile applications, the HP
8645A can be used to create complex signal simulations involving several modulation types and frequency agility. These complex RF signals can quantitatively exercise a receiver's vulnerability to a
jamming transmission. The HP 8645A can also be a fast-switching
stimulus needed to decrease production test times. The high performance and frequency agility of the HP 8645A provide capability for
both static and agile test requirements with just one calibrated signal
generator.
Specified Agile Performance
The HP 8645A provides specified signal performance in both static
and agile operation. Fully-synthesized outputs with high timebase accuracy are standard when not frequency hopping. The Fast Hop
mode activates a frequency-lock loop to allow frequency switching as
fast as 15 µsec from 128 to 2060 MHz. Over the frequency range of 8
to 2060 MHz, the fastest switching time is 85 µsec and outputs below
8 MHz require 500 µsec. Frequency accuracy of each output is better
than ±2 ppm while in Fast Hop mode. At each frequency, a specific
amplitude can be assigned within a 20 dB range for performance tests
versus amplitude while frequency hopping. For a full test of a receiver, up to 2400 frequencies can be entered and sequences of up to 4000
frequency settings can be specified. Performance parameters such as
phase noise, spurious, amplitude accuracy, and modulation remain
high quality and are completely specified while fast hopping to insure
confident test results.
Flexible, High Performance Moduiation
For receiver measurements the HP 8645A offers independent or
simultaneous FM and AM for both static and hopped frequency tests.
The modulating signal can be the internal 0.1 Hz to 400 kHz synthesizer or an external input that allows FM deviations up to 20 MHz at
rates up to 10 MHz. In Fast Hop operation, maximum deviation is
3.5 MHz with 10 MHz rates. AM is available with up to 100 kHz
rates and 99% depth. Pulse modulation allows a 35 dB on/off ratio
with 100 nsec rise/fall times.
Complete Control of Frequency Hopping
The HP 8645A offers flexible and comprehensive control of the fre-
quency hopping output. Parameters can be entered from the front
panel, through the HP-IB port or using TTL inputs on the rear panel.
Extensive hopped frequency simulations including hop frequencies,
dwell times, hop rate, modulation, etc. can be entered into non-vola-
tile memory from the front panel. Activating a hop sequence requires
only a press of the Hop key. Agile control is available by a computer
with the added advantage of using the new Hewlett-Packard Systems
Language (HP-SL). For real-time control, rear panel inputs accept
TTL signals for triggering, dwell time and frequency selection to al-
low direct connection with the hardware under test. With this wide
Specified performance while fast hopping
FM rates to 10 MHz, deviations to 20 MHz
Low spurious and phase noise
choice of control, use of the HP 8645A can be readily customized to a
wide variety of test situations from benchtop use to ATE systems.
HP 8645A Specifications
Frequency
Range: 251.46485 kHz to 1030 MHz; 251.46485 kHz to 2060 MHz
with Option 002 or with HP 11845A 2 GHz Retrofit Kit installed,
Frequency bands: The exact endpoints of each frequency band can
be determined by dividing the 1030 to 2060 MHz band by two for
each band decrease. The specifications use approximate endpoints.
Phase offset: adjustable in 1 degree increments.
Reference oscillator stability, Option 001: <5x10^-10/day aging.
Fast Hop Operation
Frequency switching time: 128 to 2060 MHz: <15 µsec, 8 to 2060
MHz: <85 µsec, 0.25 to 2060 MHz: <500 µsec. Opt. 002: add 5 µsec.
Frequency hop range: 0.25 to 2060 MHz. With FM on, limited to
any three consecutive frequency bands.
Frequency accuracy1: ±2 ppm of carrier frequency.
Channel and sequence tables: In Fast Hop, each specific frequency
and amplitude to be output is entered into a Channel Table. The order
of channels to be output is entered into a Sequence Table.
Maximum number of channels: 2400.
Maximum number of channels in Sequence Table: 4000.
Hop rate range: fixed rates from 8 Hz to 50 kHz using internal timer.
An external input allows more range and variable rates.
Dwell time range: fixed times of 6.4 µsec to 99 msec using the internal timer. External input allows longer and variable dwell.
Learn cycle time: typically, 10 sec. to 3.5 min., depending on sequence size.
Fast Hop bus: allows real-time selection of any channel for output.
Typically, frequency switching time increases by 5 µsec.
Modulation: internal or external AM, FM, or simultaneous
AM/FM.
Output level: Allowed amplitude variation of all channels entered is
0 to 20 dB. Output level is reduced by >60 dB while switching between channels. External dc AM can be used to shape the output.
Spectral Purity
SSB phase noise (CW, AM, or FM2 operation):
Harmonics: <-30 dBc, output <10 dBm. Opt. 002, output >8 dBm:
<-30 dBc, 0.25 to 1030 MHz; <-25 dBc, 1030 to 2060 MHz.
Subharmonics: none, <515 MHz. <-60 dBc, 515 to 1030 MHz.
<-40 dBc, > 1030 to 2060 MHz.
Nonharmonics: >20 kHz offset3: <-100 dBc, <2060 MHz. <-94
dBc, > 1030 to 2060 MHz.
Residual FM1 (CW, AM, FM2 operation):
Typical SSB phase noise and spurs at 1 GHz:
Residual AM: <0.01% AM rms, 0.3 to 3 kHz post detection BW.
Typical SSB AM noise floor, offsets 100 kHz: <-l 57 dBc/Hz at
+ 16 dBm output, 0.25 to 1030 MHz. <-150 dBc/Hz at +13 dBm
output, 1030 to 2060 MHz.
Output
Maximum level: +16 dBm, 0.25 to 1030 MHz; Opt. 002: +14 dBm,
0.25 to 1030 MHz. +13 dBm, above 1030 MHz.
Minimum level: -137 dBm.
Absolute accuracy: ±1 dB, output >-127 dBm.
Reverse power protection: 50 watts from a 50 source, 25 Vdc.
Typical third order intermodulation: <—50 dBc, outputs <8 dBm.
Typical output level overrange: 2 dB more than maximum level.
Typical SWR and output impedance: < 1.7:1, 50 .
Modulation
External modulation input: Coupling is ac or dc for AM, FM and
phase modulation. Pulse modulation input is dc coupled. Displayed
deviation or depth corresponds to ±1V external input.
Simultaneous modulation: AM/FM, AM/Phase, AM/Pulse,
FM/Pulse, Phase/Pulse, AM/FM/Pulse, AM/Phase/Pulse.
Simultaneous internal/external modulation: FM and Phase.
Amplitude Modulation
Depth: 0 to 99.9%, for output <±7 dBm.
Indicator accuracy: ±(6% of setting + 1% AM), up to 90% and
<1
kHz.
Distortion, at 400 Hz and 1 kHz rates:
3 dB bandwidth3: >5 kHz, 0.25 to 8 MHz. >50 kHz, 8 to 128 MHz.
> 100 kHz, 128 to 2060 MHz.
Incidental phase modulation: <0.2 rad peak, at 30% depth and 1
kHz.
Typical external input impedance: 600 .
Frequency Modulation
FM deviation and rate: In the highest frequency band of 1030 to
2060 MHz, the maximum FM peak deviation is 20 MHz for standard
operation and 3.52 MHz for Fast Hop. Maximum FM rate (3 dB
bandwidth) in the 515 to 1030 MHz band and above is 10 MHz. Di-
vide rate and deviation by two for each frequency band decrease.
FM indicator accuracy": ±10%, <50 kHz rate and <10% of maxi-
mum deviation (<50% of maximum deviation in Fast Hop.)
FM distortion:-Rates 20 Hz to 100 kHz: <2.7%, deviation <2% of
maximum available (Fast Hop: <10% of maximum deviation.)
Carrier frequency accuracy in FM: ±0.4% of deviation setting, ac or
dc coupled. Typically add 1% of deviation in Fast Hop.
Incidental AM: <0.5%, deviation limited to <6% of max. or 20 kHz.
Typical external FM group delay: 30 µsec for rates 20 Hz to 20 kHz,
decreases to <1 µsec at rates >200 kHz. Fast Hop: <1 µsec.
Typical external FM input impedance: 50 or 600 .
Pulse Modulation
On/off ratio: >35 dB.
Rise/fall time: <100 nsec, between 10% and 90% response points.
Maximum pulse repetition frequency: 1 MHz.
Minimum pulse width: 0.5 µsec.
Typical output level accuracy: ±2 dB.
Typical external input levels and impedance: on: >3.0V peak;
off: <0.8V peak. Damage level: >±10V peak. 600 .
internal Modulation Source
Waveforms: sine, square, sawtooth and white Gaussian noise.
Frequency range: sine, white Gaussian noise: 0.1 Hz to 400 kHz.
Square, sawtooth: 0.1 Hz to 50 kHz.
Frequency accuracy: same as internal reference oscillator.
Output level: Typically, 1 Vpk max. into 600 . Accuracy: ±20 mV.
Output level resolution: 2 mV. Typical impedance: 600 .
Distortion: <0.1%, output at 1V peak and <15 kHz.
Frequency Sweep
Phase continuous sweep: linear sweep with times from 10 msec to
10 sec, not dependent on span. Maximum span is 40 MHz from 1030
to 2060 MHz frequency band, divided by two for each band decrease.
Fast Hop sweep: linear or log stepped with times from 10 msec to
100 sec. Number of steps varies with time selected. Typical time per
step is 30 µsec for outputs within 128 to 2060 MHz, 170 µsec for 8 to
2060 MHz, and 650 µsec for 0.25 to 2060 MHz.
Sweep control and markers: X-axis: 0 to +10V. Z-axis: +5V re-
trace, +1V trace, 0V markers. Three markers available.
General
Remote control: HP-IB (IEEE-488.2-1987). The control language
used is the Hewlett-Packard Systems Language (HP-SL). All front
panel functions except power switch and knob. A unique Fast Hop
bus interface accepts TTL levels for frequency agile control.
Operating temperature range: 0 to +55° F.
Leakage: meets Mil Std 461B RE02 and FTZ 1046.
Storage registers: 10 full function and 40 freq./ampl. locations.
Memory erasure: all memory contents according to Mil Std 380-
380.
Weight: net, 31 kg (69 lbs); shipping, 42 kg (95 lbs).
Size: 177H x 426W x 624mmD (7" x 16.8" x 24.6").
Ordering Information Price
HP 8645A Agile Signal Generator4 $32,000
Opt 001 High stability time base +$1,500
Opt 002 2 GHz output +$6,000
Opt 003 RF connectors on rear panel only +$300
Opt 907 Front handle kit (5061-9690) +$65
Opt 908 Rack flange kit (5061-9678) +$35
Opt 909 Rack flange kit with front handles +$90
(5061-9684)
Opt 910 Provides an additional operation/calibration +$190
manual (08645-90023) and 2 service manuals
(08645-90025)
Opt 915 Add service manual (08645-90025) +$65
Opt W30 Extended repair service. See page 725 +$775
HP 11845A 2 GHz Retrofit Kit $6,180
08645-61116 Service kit $500
9211-2662 Transit case $550
1490-0913 Transit case wheels $210
1494-0059 Non-tilting rack slide kit $100
1494-0063 Tilting rack slide kit $190
4
HP-1B cables not included. For description and price, see page
569.
Loading...