The AN1840 is a microprocessor controlled, digitally
synthesized spectrum analyzer. The AN1840 utilizes a numeric
keypad, dedicated function keys, multitask Soft Function
Keys and a high resolution LCD to display, enter and edit
functions and data. Testing is done manually using external
front panel controls or remotely through the RS-232 or
IEEE-488 external interface. Microprocessor controlled
memory allows storage and recall of parameters for each of
the major testing modes as well as storage and recall of
traces for signal comparison.
1-2 STANDARD FEATURES
The AN1840 Spectrum Analyzer spans a range from 0 Hz to 26,5
GHz, at up to +30 dBm. The AN1840 input impedance is 50 Ω.
The AN1840 operates as a Spectrum Analyzer, Frequency
Counter, Digital Oscilloscope or AM/FM Receiver.
The AN1840 Display is a color VGA thin film transistor (TFT)
LCD. The graticule area on the LCD has 500 horizontal pixels
by 256 vertical lines. The Display shows up to 4 traces on
the screen for comparison of live or previously stored
signals. The 80 dB of dynamic range in the Logarithmic
display mode is expandable to 120 dB. The Linear display
mode provides dB units in addition to the regular power and
voltage units, eliminating the need for external conversions.
1-2-2 MEASUREMENTS WITH THE AN1840 SPECTRUM ANALYZER
The AN1840 tests and measures spectral purity, mixer
products, modulation, carrier levels, suppression in Single
Side Band Radios, harmonic levels, RF, EMI, FM deviation, AM
% modulation, signal limits and distortion. The AN1840 is
not limited to only these measurements.
1-2-3 INPUT LEVEL
Maximum input level to the AN1840 is +20 dBm with <10 dB
internal attenuation or +30 dBm with >10 dB internal
attenuation. Maximum pulsed level is +40 dBm with >10 dB
CAUTION: SIGNALS EXCEEDING THE MAXIMUM INPUT LEVEL OF +30
dBm MAY CAUSE DAMAGE TO THE SPECTRUM'ANALYZER.
The AN1840 Spectrum Analyzer incorporates the use of single
and dual markers on the Display. Markers provide easy
measurement of any portion of displayed signal. The Delta
function shows differences in levels and time or frequency.
Markers have peak search capability.
1-2-5 EXTERNAL ATTENUATION/GAIN OFFSET
An offset value compensating for external attenuation and
gain eliminates manual calculations.
By setting an offset value equal to the sum of all external
attenuation and gain factors, the AN1840 automatically
displays true levels for signals requiring amplification or
attenuation prior to entry into the AN1840. The offset also
compensates for losses present when dealing with antenna
1-2-6 FREQUENCY COUNTER
The frequency counter provides selectable resolution at
narrow or wide frequency span settings. Resolution is set to
1, 10, 100 or 1000 Hz.