Anritsu MS2651B User manual

MS2651B/2661B
Spectrum Analyzer
9 kHz to 3 GHz
For various applications

Portable at Only 11 kg
In the latest radio communications systems, the develop-
ment of improved frequency efficiency and sophisticated
digital functions are emphasized. The MS2651B/2661B
portable spectrum analyzers are ideal for analyzing the
signals of above systems, device and related equipment.
They are fully synthesized spectrum analyzers covering
a wide frequency range from 9 kHz to 3 GHz. They have
superior basic performance such as high C/N ratio, low
distortion, and high frequency/level accuracies and are easy
to operate. In addition, they use resolution bandwidth filters
with a much better selectivity than previously possible. The
large selection of options is available to handle a wide
range of applications at reasonable cost.
The MS2661B is designed for manufacture and installation
of radio equipment and devices, while the MS2651B is
meant for maintenance applications.
■Compact and lightweight
(11 kg in standard configuration)
●Easy portability for installation and maintenance
■High C/N and superior distortion characteristics
●Measurement speed improved by using 100 dB log
dynamic range
■Easy-to-use, simple operation
●Built-in “Measure” function for evaluation of radio equip-
ment (Frequency counter, C/N, channel power, adjacent
channel power, occupied frequency bandwidth, burst aver-
age power and template pass/fail function)
●User-defined function
●Zone marker/zone sweep
●Two-screen display
●FM demodulation waveform display
●Memory card interface (for saving/recalling trace data and
parameter and for saving screen image in bitmap format)
■Options support wide range of applications
●High stability crystal oscillator
●Narrow resolution bandwidth (MS2661B only)
●High-speed time domain sweep
●Trigger/gate circuit
●AM/FM demodulator
●Pre-amplifier
●Centronics interface (can not be installed with GPIB simul-
taneously)
●QP detector
●Television monitor
●DC coupled input (MS2661B only)
●Tracking generator
●75 Ωinput
●75 Ωtracking generator
■Easy to set up automatic measurements
●Controller function built-in (PTA)
●Built-in RS-232C and GPIB (standard)
●Various application software
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●Small and weighing only 11 kg
The MS2651B/2661B are compact and lightweight, measur-
ing 320 (W) ×177 (H) ×351 (D) mm and weighing only 11
kg. In addition to benchtop use, they can be carried easily
for field use, making them the ideal choice for manufactur-
ing and maintenance of radio equipment.
●Synthesized local oscillator
The synthesized local oscillator design permits stable mea-
surement without disturbance due to frequency drift of the
spectrum analyzer itself. The level stabilizes in 30 minutes
after power-on, making these units especially suitable for
on-site maintenance and adjustment where work must be
completed quickly.
●Counter with 1 Hz resolution
A full complement of frequency counter functions are pro-
vided. Resolution is a high ±1 Hz even at full span, and
high-speed frequency measurements can be performed.
The high sensitivity compared with ordinary counters makes
it easy to select one signal from many and to determine its
frequency.
Compact, Lightweight, and Powerful
●Superior distortion characteristics
The MS2661B boasts extremely low harmonic distortion
levels, including a second harmonic distortion of –75 dBc*1
and a two-signal third order intermodulation distortion of
–80 dBc*2making it suitable for measuring harmonic com-
ponents and for evaluating the non-linearity of high-power
amplifiers.
*1200 MHz to 1.5 GHz, mixer input: –30 dBm
*2100 MHz to 3 GHz, frequency difference between signals:
≥50 kHz, mixer input: –30 dBm
●100 dB display dynamic range
In measurements requiring a wide dynamic range
such as adjacent channel power measurements, the
MS2651B/2661B can display more than 80 dB on a single
screen.
●Highly-accurate measurement
Auto-calibration ensures an overall level accuracy of within
±1.3 dB.
A span accuracy of 2.5% and 501 sampling points ensure
accurate occupied frequency bandwidth and adjacent chan-
nel power measurements.
●High C/N ratio
Excellent noise sideband characteristics are required for
analysis of weak signals adjacent to strong signals. The
MS2661B has low noise sidebands of below –100 dBc/Hz
(10 kHz offset), making it suitable for measurement of adja-
cent channel power of both analog and digital radio commu-
nication equipment.
Frequency measurement (1 Hz resolution)
Noise sidebands measurement (10 kHz offset)
Two-signal third order intermodulation
Occupied bandwidth measurement
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●MS2651B for maintenance,
MS2661B for manufacturing
The optimum applications for the MS2651B and MS2661B
are maintenance and manufacturing, respectively, owing to
their basic performance such as noise sidebands, average
noise level and distortion free dynamic range. The
MS2651B is a good choice where there is no need to
measure parameters such as adjacent channel power
or harmonic distortions. High frequency/level accuracy
and 1 Hz-readout-resolution counter which are required
especially for maintenance are common features to the
MS2651B and MS2661B. The MS2661B is best for manu-
facturing. It is capable of highly-accurate measurement of
adjacent channel power, harmonic spurious components,
and in-band spurious components, and can also be used
for development.
Model MS2651B MS2661B
Noise sideband*1≤–90 dBc/Hz ≤–100 dBc/Hz
Averagenoiselevel*2≤–110 dBm ≤–115 dBm
2nd harmonic: 2nd harmonic:
>70 dB >80 dB
(100 to 500 MHz) (200 to 500 MHz)
3rd intermodulation 3rd intermodulation
distortion: distortion:
>76.6 dB >83.3 dB
(10 to 1000 MHz) (100 to 1000 MHz)
Maximum
distortion free
dynamic range
(RBW: 1 kHz)
–60
–90
–80
–70
–60
–50
–40
–30
–20
–40 –20 0 +20
*11 GHz, 10 kHz offset
*21 MHz to 1 GHz, RBW: 1 kHz, VBW: 1 Hz, RF ATT: 0 dB
2nd harmonicdistortion
Two signals 3rd order
intermodulation distortion
MS2661B
MS2651B
100 MHz to 3 GHz
800 MHz to 1 GHz
200 MHz to 1.5 GHz
Average noise level
10 MHz to 3 GHz
100 MHz to 1.5 GHz
Distortion characteristics
Mixer input level (=input level – RF ATT)
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Average noise level (dBm)
Distortion relative value (dB)

●Simple operation
Users require ease of operation in a wide variety of con-
texts. For greater ease, in addition to simplifying the panel
keys and key layout, also menu page configuration is well
organized and “page-learning”as well as “user-defined”
functions have been added to minimize the steps required
for a given procedure.
●Bright color screen
A 5.5" bright color TFT LCD is used to display scales, mea-
sured waveform data, settings and other information in dif-
ferent easy-to-read colors. Each color can be changed if
required. When the soft key display is turned off, the scale
area enlarges to 180 (W) ×80 (H) mm, comparable to an
8" CRT.
●Radio equipment evaluation functions
(“Measure” functions)
A full range of functions including measurement of power
levels, frequencies, adjacent channel power, and mask and
time template measurements are provided for performance
evaluation of radio equipment. Key operation is simple and
high-speed calculations make the measurement fast and
efficient.
Convenient Easy-to-Use Functions
Burst average power measurement
Mask measurement
Channel power measurement
Adjacent channel power measurement
Time template measurement
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●FM-demodulated waveform display function
This function displays FM-demodulated waveforms with an
accuracy of 5% over the range ±10 kHz to ±1 MHz. When
used with high-speed time domain sweep (Option 04) and
trigger/gate circuit (Option 06), frequency deviation of the
modulated signal, and frequency switching times of radio
equipment and VCOs, can be measured.
●Zone markers and multimarkers
Zone markers can be set automatically at the peak signal
within a given marker range, enabling quick measurement.
By using the multimarker function, automatic measurements
can be performed at up to ten marker points, and the
results displayed in a table. Multimarkers have functions
for harmonic measurements, highest 10 points and manual
setting.
●Zone sweep and multi-zone sweep functions
Sweeps can be limited to zones defined by zone markers
reducing sweep time. This zone sweep function can be
combined with “measure”functions such as “noise measure”
which can direct readout the total noise power within the
zone, and reduces measurement time greatly. The multi-
zone sweep function enables up to ten zones to be swept.
●Multi-screen display
The Trace A and Trace B waveforms are superimposed on
the same screen, and two spectra with different frequencies
are displayed simultaneously. In addition, it is possible to
simultaneously display spectrum and time domain screens
for the same signal. The multi-screen display permits effi-
cient signal level adjustment and harmonic distortion mea-
surement, too. Furthermore, in addition to being able to
display amplitude in the time domain, it is also possible to
display the FM demodulation waveform.
Spectrum and FM-demodulation waveform
Multimarker (highest 10 points)
Multimarker (harmonics measurement)
Multi-zone sweep
Two traces with different frequencies
Spectrum and time domain measurement 7

●User-defined functions
Measurement programs downloaded to the spectrum ana-
lyzers from a personal computer or memory card can be
executed by defining menu keys. The measurement pro-
gram is executed simply by pressing the predefined key,
with no further operation. Other panel and function keys
can also be predefined in the same way.
Measurement pro-
grams definition (down-
loaded from personal
computer)
User-defined menu
Panel and function
keys definition
●Screen image bitmap saved to memory card
Instead of printing a hard copy of the screen, it is also pos-
sible to save the screen image data to a memory card in
bitmap format. Editing the saved bitmap data using a PC,
makes report writing easy.
When the mode to save the
screen image in the bitmap for-
mat to the memory card is
selected as a copy method at
the hard copy function, just one
press of the copy key saves the
screen image as a bitmap format
to the memory card. And the file
number of each saved file is
incremented automatically.
The screen image data can also
be saved to the memory card
using the save function. In this
case, the file number of the
saved file can be specified.
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Full Range of Options
Full lineup of options to select required performance and
functions with minimum capital investment
●To boost basic performance
Reference crystal oscillator (Option 01)
Adding the optional reference oscillator with a stability of 2
×10-8/day and 1 ×10-7/year, increases the accuracy of fre-
quency measurements even further.
Narrow resolution bandwidth (MS2661B only, Option 02)
Adding the option for a resolution bandwidth of 30 Hz, 100
Hz and 300 Hz greatly improves frequency resolution.
Pre-amplifier (Option 08)
The pre-amplifier improves the sensitivity (noise figure) of
the spectrum analyzer, and is best used when studying
interference signals and other low-power signals. It covers a
frequency range from 100 kHz to 3 GHz.
●For testing digital mobile communication
equipment
High-speed time domain sweep (Option 04)
Testing of TDMA-type radio equipment includes time
domain (zero-span) measurements of antenna power, tran-
sient response characteristics of burst transmissions, trans-
mission timing, and other quantities. The high-speed time
domain sweep option boosts sweep time to 12.5 µs and
resolution to 0.025 µs. This option must be used with the
trigger/gate circuit (Option 06).
Trigger/gate circuit (Option 06)
Burst signal and TV signals etc. can be stably measured
using the trigger function in time-domain measurements.
One of the external, video wide IF video, line or TV is selec-
table. This makes a variety of TDMA radio equipment tests
possible, including template comparison using pre-trigger
and post-trigger delay functions, and gate spectrum analy-
sis using the gate sweep function. Previously, the trigger
output from an external detector was required in gate spec-
trum analysis. However, this option for the MS2651B/2661B
has a 20 MHz wide IF video trigger function, eliminating the
need for trigger output from an external detector.
Low-power signal measurement using RF pre-amplifier
High-speed time-domain measurement (TS=12.5 µs)
Wide IF video trigger function
Wide IF video trigger and gate functions
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●For CATV maintenance
75 Ωinput (Option 22)
Converts RF input impedance to 75 Ω(100 kHz to 2.5 GHz)
75 Ωtracking generator (Option 23)
For 75 Ωoutput
AM/FM demodulator (Option 07)
Demodulates AM/FM signals, enabling audio monitoring
using internal speaker or earphones.
This is useful for distinguishing between signals and inter-
fering spurious.
Television monitor (Option 16)
This option displays TV (NTSC or PAL) signals. When used
with the AM/FM demodulator (Option 07), audio signals can
be monitored simultaneously. With addition of high-speed
time domain sweep (Option 04) and the trigger/gate circuit
(Option 06), measurement of CATV parameters such as
carrier level/frequency, C/N, modulation, distortion, hum and
low-frequency interference etc. becomes possible.
●For measurement of filter frequency
response and antenna impedance response
Tracking generator (Option 20) covers a frequency range
of 9 kHz to 3 GHz at levels of 0 to –60 dBm while tracking
generator (Option 23) covers 100 kHz to 2.5 GHz at levels
of +44 to +104 dBµV.
●Superior frequency/level stability
The synthesized local oscillator permits stable measure-
ment of narrow-band crystal filters without disturbance by
drift. Moreover, the bandwidth of bandpass filters can be
measured accurately by using the occupied bandwidth
measurement function after sweeping.
●Multimarkers
Markers can be displayed at up to 10 points by using the
multimarker function even while the tracking generator is in
use. Furthermore, by setting the zone marker width other
than spot, fine adjustment of the marker position is unnec-
essary because the peak or dip within the zone is located
automatically.
NTSC TV waveform
Bandpass filter measurement
Example of dip marker
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