Atec Agilent-8757D User Manual
Agilent 8757D
Scalar Network Analyzer
Data Sheet
Accurate measurement of transmission and
reflection characteristics is a key requirement in
your selection of a scalar network analyzer. To
help you achieve these goals, Agilent Technologies
offers you a choice of microwave scalar measurement solutions which provide an excellent balance
of cost, system versatility, and measurement
precision.
Agilent 8757D overview of features
• Four display channels
• Three detector inputs
• An optional fourth detector input
• An optional internal power calibrator
• Accurate power measurements with
Agilent 85037 series precision detectors
• High resolution color display
• Internal plotter/printer buffer
• +16 to –60 dBm dynamic range
• AC/DC detection modes
• 101 to 1601 measurement points/trace
• Noise figure measurement display capability
• Compatible with the Agilent 85025 and 85026
series detectors and the Agilent 85027 series
directional bridges
• Limit line testing (channels 1 and 2)
• Adaptive normalization
• Cursor search functions (max, min, n dB, BW)
Specifications describe the instrument’s warranted performance over the
temperature range 0 to 55 °C (except where noted). Supplemental characteristics
are intended to provide information useful in applying the instrument, by giving
typical but non-warranted performance parameters. These are denoted as “typical,”
“nominal,” or “approximate.”
Agilent 8757D scalar network analyzer
The Agilent 8757D has four independent display
channels that process the signals from the Agilent
85037 series precision detectors, 85025 and 85026
detectors, and the 85027 series directional bridges
for logarithmic display, in single channel or ratio
mode. Three (optionally four) detector inputs are
provided.
Display
Horizontal resolution
The number of points (horizontal resolution)
that can be selected depends on the number of
traces displayed.
Network analyzer Traces Selectable number of points
8757D 1 101, 201, 401, 801, 1601
2 101, 201, 401, 801
3, 4 101, 201, 401
LCD Display 640 (horizontal) x 480 (vertical) resolution
A display is considered faulty if:
• A complete row or column of “stuck” or “dark”
pixels.
• More than six “stuck on” pixels (but not more
than three green) or more than 0.002% of the
total pixels are within the LCD specifications.
• More than twelve “dark” pixels (but no more
than seven of the same color) or more than
0.004% of the total pixels are within the LCD
specifications.
• Two or more consecutive “stuck on” pixels or
three or more consecutive “dark” pixel (but no
more than one set of two consecutive dark
pixels) “Stuck on” of “dark” pixels less than
6.5 mm apart (excluding consecutive pixels)
Display modes
All analyzer display channels can display any one
of the detector inputs or any ratio combination
of detector inputs.
Log magnitude
dBm: single channel power measurement
dB: relative power measurement (ratio or relative
to trace memory)
SWR
Relative measurements (normalized or ratio
measurements) can be displayed in SWR.
Channels 1 and 2 only: 401 points or fewer
AUX voltage
The rear panel BNC input ADC IN can be measured and displayed in volts (–10 to +10 volts).
Typical maximum error is 60 mV.
Color settings
Up to 8 operator-selectable colors are available
for LCD attributes, such as the grid, measurement
traces, and labels.
Sweep time
The minimum sweep time depends on the number of traces displayed and the number of points
selected.
Minimum sweep time (ms)
Number (log magnitude format)
of points 1 trace 2 traces 3 traces 4 traces
101 40 50 60 70
201 50 75 90 100
401 100 100 150 200
801 200 250
1601 400 NA NA NA
Averaging
2, 4, 8, 16, 32, 64, 128, or 256 successive traces can
be averaged.
Smoothing
Provides a linear moving average of adjacent data
points. The smoothing aperture defines the trace
width (number of data points) to be averaged, and
ranges from 0.1% to 20% of the trace width.
Normalization
Traces are stored and normalized with the highest
resolution, independent of display scale/division or
offset. With adaptive normalization on the Agilent
8757D, calibration data is interpolated when the
frequency span is decreased.
Limit lines
Limit lines facilitate quick pass/fail decisions.
Limits can be any combination of flat or sloped
lines or single points up to 12 segments. They
are only available for channels 1 and 2, for traces
with 401 points or fewer, and can be stored in
save/recall registers 1 through 4.
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Internal save/recall registers
Up to 9 complete front panel states may be saved
or recalled. If the source (Agilent PSG, 8360 or 8370
series) is connected to the 8757 system interface,
the front panel states of both the network analyzer
and source are saved. Registers 1 through 4 store
the instrument state and the memory traces for
channels 1 and 2. The memory traces for channels
3 and 4 are not stored. Registers 5 through 9 only
store the instrument state.
Display Scale Display Vertical
mode resolution range resolution
dBm 0.1 to 20 dB/div –80 to +80 dBm 0.003 dB
(1/2/5 sequence)
dB 0.1 to 20 dB/div –90 to +90 dB 0.006 dB
(1/2/5 sequence)
Normalized 0.1 to 20 dB/div –180 to +180 dB 0.01 dB
ratio (1/2/5 sequence)
measurements
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Modulator drive
The modulator drive output of the 8757 scalar
analyzer provides the circuitry to drive the
8340/50/60/70 series synthesized sweepers and the
Agilent 11665B modulator. Modulation drive may
be turned on and off via the front panel or GPIB.
In the “off” state, the modulator drive signal turns
the 11665B fully on for minimum insertion loss.
The 8360 and 8370 synthesized sweepers have the
capability of modulating signals, so an external
modulator such as the 11665B is not necessary
when using the 8360/70 series.
Frequency: 27,778 Hz ±12 Hz
Symmetry: 50% ±1%
Stop sweep
Used with the PSG, 8360 and 8370 series when
controlled by the 8757 system interface to stop the
sweep at band crossings and at the end of sweep.
SWR 0.02 to 10 units/div 1.0 to 37.0 0.01 at 1
(1/2/4 sequence) 0.1 at 10
0.27 at 30
AUX 0.025 to 5 V/div –10 to +10 V 0.001 V
voltage (1/2.5/5 sequence)
1. 0.01 dB for display cursor
Modulation requirements
Applies to the Agilent 85037 series precision detectors, 85025/26 series detectors, and 85027 series
directional bridges in AC mode.
Square-wave amplitude modulation
Frequency 27,778 Hz ±20 Hz
≥30 dB on/off ratio
45% to 55% symmetry
Rear panel connectors
Sweep voltage requirements (Sweep in)
Horizontal sweep voltage, normally provided by
the sweeper, from 0 to 10 volts.
Marker and blanking requirements (Pos z blank)
Blanking and marker signals are provided by the
sweeper through the “Pos z blank” input on the
rear panel of the Agilent 8757.
Voltage levels
Blanked: +5 V typical
Unblanked: 0 V typical
Marker: –4 V typical
Active marker: –8 V typical
ADC in
An input connector for auxiliary voltage input
in the –10 to +10 volt range. This voltage can be
displayed (in volts) on any channel.
Control 1 and control 2
These connectors provide digital output signals
(TTL open-collector) as a user convenience for
driving other peripheral equipment in a GPIB
controlled system.
Video outputs
Used to drive an external color monitor that has
the following characteristics:
8757D with LCD monitor (VGA input on the
analyzer’s rear panel)
• VGA compatible
8757D with CRT monitor (RGB inputs on the
analyzer’s rear panel)
• Red, green, and blue (RGB) BNC inputs, sync
on green
• 75 ohm input impedance
• 26.5 kHz horizontal scan rate
• 60 Hz vertical refresh rate
• 1 V p-p (typically 0.7 V = white; 0 V = black;
-0.3 V = sync)
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Agilent 8757D scalar network analyzer, continued
GPIB
Interface
GPIB operates according to IEEE 488-1978 and
IEC-625 interface standards.
Interface function codes
SH1, AH1, T6, TE0, L4, LE0, SR1, RL1, PP0, DC1,
DT0, C0, E1.
Transfer formats
Data can be transferred either as ASCII strings
or as 16-bit integers. Readings may be taken at a
single point, or an entire trace may be transferred
at once.
Transfer speed
ASCII format, 401 point trace: 500 ms typical
ASCII format, single point: 10 ms typical
Binary format, 401 point trace: 30 ms typical
Binary format, single point: 7 ms typical
Programmable functions
All front panel functions except power on/off
are programmable. The 8757D is compatible with
all appropriate 8757A/C scalar analyzer programming codes.
User-accessible display graphics
HPGL subset that allows user to display test
setup diagrams and operator instructions on the
analyzer CRT/LCD.
Interrupts
GPIB service interrupts (SRQs) are generated for
the following conditions:
System interface
The Agilent 8757 system interface is a dedicated
GPIB port used exclusively by the 8757 to control
and extract information from a swept source, a
digital plotter, and a printer.
Compatible swept sources
The following swept sources are specifically made
to complement the 8757 system. With them, the
8757 is able to display start, stop, and marker frequencies, save and recall front panel states of both
the sweeper and the scalar analyzer, preset both
instruments simultaneously, and alternately sweep
two different frequency or power ranges and display both simultaneously:
• Agilent PSG1 signal generators (Option 007)
• Agilent 8360 series synthesized sweeper
• Agilent 8370 series synthesized sweeper
Printers
For a list of compatible printers, consult our
printer-compatibility guide Web page. Its URL
location is http://www.agilent.com/find/pcg. Or go
to www.agilent.com and use keyword search
printer guide.
Internal plotter/printer buffer
The GPIB buffer speeds measurements by returning the control to the analyzer while outputting
data to a plotter or printer. Output two channels
(401 points each) of information to the buffer in
typically less than 5 seconds.
Note: In order to use the currently available printers a GP-IB
to parallel port adapter is needed. Adapters are available
from Intelligent Interfaces. Please see their website at
http://www.intelligentinterfaces.com.
• Front-panel key pressed
• Operation complete
• Illegal command
• Instrument self-test error
• Limit test failed
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URL location: http://www.agilent.com/find/psg
4
Disk interface
The 8757D provides the capability to store and
retrieve the analyzer’s instrument state, measurement data, and user accessible display graphics
to and from an external GPIB disk drive that is
compatible with command subset CS/80. Data files
are stored in Agilent’s standard LIF format and
can be read by a wide variety of computers, including the HP 9000 series 200 or 300. Files can be
stored in binary or ASCII format.
Disk drive
Agilent no longer offers Option 802, the HP 9122C
disk drive. Agilent 8757D-compatible disk drives
are available from ISA, Inc. In the U.S., contact
Saaya, Inc. (formerly known as ISA, Inc.).
Elsewhere, contact ISA Company, Ltd. at
http://www.isa-j.co.jp/.
General information
Temperature range
Operating: 0 to 55 °C
Storage: –40 to 75 °C
Power requirements
48 to 66 Hz, 100/120/220/240 V ±10%,
typically 155 VA
Dimensions: 178 H x 425 W x 482 mm D
(7.0 x 16.75 x 19.0 in)
Weight: Net 22 kg (48 lb), Shipping: 28 kg (61.5 lb)
Power calibrator (Option 002 only)
The 8757D’s internal power calibrator provides
a 50 MHz reference standard for characterizing
the absolute power accuracy and dynamic power
accuracy of the 85037 series precision detectors.
Frequency: 50 MHz ±0.2 MHz
Output power: (25 ±5 °C)
Range: +20 to –50 dBm
Accuracy at 0 dBm: ±0.05 dB
Linearity: (over any 10 dB range)
±0.08 dB (+20 to +10 dBm)
±0.04 dB (+10 to –30 dBm)
±0.06 dB (–30 to –50 dBm)
Ordering information
Agilent 8757D scalar network analyzer (select one)
8757D-700 Standard network analyzer
8757D-001 Adds fourth detector input
8757D-002 Adds internal power calibrator
8757D-012 Adds fourth detector and internal
calibrator
SWR: ≤1.05
Modes of operation
DC Mode (unmodulated)
AC Mode (modulated at 27,778 Hz ±12 Hz)
Connector: Type-N (f)
Accessory included
A Type-N (m) to 3.5-mm (f) adapter is provided
to allow calibration of the 85037B (3.5 mm)
precision detector.
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