14 News from Rohde& Schwarz Number 163 (1999/III)

Signal Analyzer FSIQ

Two spectrum analyzer families forthird-generation mobile radio …

Spectrum Analyzer R 3267/R 3273

… an ideal match offering solutionsfor every requirement

Articles

Advantest and Rohde& Schwarz havebeen cooperating in sales and designsince 1992. The products of the twopartners, particularly the spectrumanalyzer families, are aimed at differ-ent market segments and customersand so perfectly complement eachother. This strategy continues with theintroduction of Spectrum AnalyzersR 3267 and R 3273 and SignalAnalyzer FSIQ [1], specially developedfor measurements on mobile radios ofthe third generation. The two instru-ment families suit any requirement andbudget and come from a single source.

With its extremely wide dynamicrange, minimal measurement uncer-tainty and high flexibility, FSIQ fromRohde & Schwarz is the ideal instru-ment for development, verification andquality assurance but also in the pro-duction of base stations.

By contrast, the new Analyzer Fami-lies R3267/3273 from Advantest areespecially suitable for service and in-stallation and for the production ofmobile stations. Features of the unitsthat particularly count here are port-ability, standard-conformal test rou-tines and price.

Application Family Family FSIQ R3267/R3273

Development •Verification •Production test of base stations •Production test ofmobile stations •Quality assurance •Installation •Service •

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News from Rohde& Schwarz Number 163 (1999/III) 15

Articles

The FSIQ family is a follow-on devel-opment from spectrum analyzers ofthe FSE series. Characteristics likedynamic range, accuracy and phasenoise were further improved for highlydemanding measurements on W-CDMAsignals. FSIQ comes in three models• FSIQ3 20 Hz to 3.5 GHz• FSIQ7 20 Hz to 7 GHz• FSIQ26 20 Hz to 26 GHz

Because of the CDMA transmissionused in mobile radio of the third gener-ation, adjacent-channel power meas-urement is of particular importance.FSIQ's wide dynamic range is anessential feature especially when com-ponents like high-power output stagesare measured, whose specificationsmust be far superior to those of the over-all system. With a TOI of 20 dBm

(FSIQ7), noise figure of 15 dB andtypical phase noise of –153 dBc/Hzat 5 MHz from the carrier and–155 dBc/Hz at 10 MHz, FSIQachieves more than 75 dB dynamicrange in the adjacent channel andmore than 85 dB in the alternate chan-nel. In response to customer requests,phase noise at 5 MHz and 10 MHzfrom the carrier was improved by morethan 5 dB compared to first-generationFSIQ. This ensures that the analyzer is10 dB better than the DUT even whenmeasuring a component in the alternatechannel, so measured results are notinfluenced. Built-in routines simplify si-multaneous measurement of adjacent-channel power in up to five channels.

Due to the improved phase noise, evenspurious emissions of GSM base sta-tions can be measured without anyneed for complex external filtering.

The amplitude distribution of aW-CDMA signal – which considera-bly deviates from white noise – meansthat reliable and reproducible powermeasurement results can only beachieved on an rms basis. For this rea-son FSIQ and the analyzers of the FSEfamily comprise an rms trace detectoras standard, which is able to accurate-ly measure signal power at any pointof the trace.

Spectrum Analyzer Family FSIQ from Rohde& Schwarz

New spectrum analyzer family from Advantest

The concept of the new analyzers isbased on a traditional spectrum ana-lyzer with a digital section for the dif-ferent digital telecommunication stand-ards in use today and intended for thenear future. Model R3267 covers afrequency range of 100 Hz to 8 GHz,model R3273 through to 26.5 GHz.

All mobile-radio standards are avail-able as software options: GSM900,GSM1800/1900, DECT, PDC, PHS,IS-136, IS-95, W-CDMA (NTTDoCoMo, ARIB, 3GPP), etc, and up-grades can be loaded from disk drive.Up to three standards at a time canbe combined in the same analyzer.

To meet the high RF performancerequirements of the new digital stand-ards GSM+ (HSCSD, GPRS), GSM++

(EDGE) and W-CDMA, Advantestenhanced the specifications of its spec-trum analyzers. Major specificationssuch as a noise floor of–150 dBm/Hz at fre-quencies up to 3.6 GHz,phase noise down to–148 dBc/Hz at 5 MHzand <–153 dBc/Hz at10 MHz from thecarrier, plus typical TOIof +15 dBm meet themost stringent demandson ACPR (adjacent-channel power ratio)measurements. TypicalACPR values achieva-ble for W-CDMA signals with 16code channels are –72 dBc/Hz forthe adjacent channel (5 MHz) and–80 dBc/Hz for the alternate channel

(10 MHz). The analyzers additionallyfeature input attenuation in 5 dB steps,which also helps to meet requirements

for a wide dynamicrange.

The analyzers offer alarge number of key-stroke functions such asadjacent-channel pow-er, occupied band-width, power (channel,total, average), spuri-ous emissions, harmon-ics and frequencycounter. Also providedare four detectors, two

of which can be simultaneously dis-played on the screen, eg for

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Advantest spectrum ana-lyzers comprise a 3.5"disk drive, a 6.5" TFTcolour display and areequipped with GPIB, RS-232-C interfaces, parallelports and a VGA output.Weight: 17 kg.

16 News from Rohde& Schwarz Number 163 (1999/III)

With a measurement uncertainty of<±1 dB up to 2.2 GHz or <±0.5 dBwhen the increased level accuracyoption is used, FSIQ can be employedin many applications instead of a ther-mal power meter. An additionaladvantage is that power can be meas-ured selectively and in a much wider

range than with a thermal powermeter.

Four traces – even with differentdetectors – can be simultaneously dis-played, so the crest factor of W-CDMAsignals, for instance, is very easilydetermined. FIG 1 illustrates this on asignal with 15 code channels. Onetrace shows the average power meas-ured with an rms trace detector, thesecond the peak power using a peakdetector. The crest factor depends verymuch on the code channels used, be-sides playing an important role in thedesign of amplifiers and meetingadjacent-channel power specifica-tions, so fast and simple measurementsare of particular importance in devel-opment.

A vector signal analyzer capable ofmeasuring modulation errors up to asymbol rate of 6.4 Msymbol/s withvery low inherent error (<1 % forQPSK, 4.096 Mchip/s) is standardequipment in FSIQ. Preset standards(GSM, PDC/PHS, DECT, IS-95 andmany others) can be called up, ormodulation parameters can be user-selected (demodulator, symbol rate,baseband filtering, etc). Analog mod-ulation too can be analyzed, the sett-ling and spurious FM of synthesizerswith the FM demodulator for instance.This high flexibility in modulation meas-urements is enhanced by applicationsoftware packages. FSE-K4 forinstance supports automatic measure-ment of phase noise. Using the noisemeasurement software option, noise

measurement of crest factor. Fast timedomain sweep down to 1 µs and gat-ed sweep are standard functions.

The software options for the digitalcommunication standards are contin-ually updated to satisfy future devel-

Signal Analyzer FSIQ(cont´d)

Spectrum Analyzer R3267/R3273(cont´d)

their timing determined. In conjunctionwith the ACP test, which requires awide RF dynamic range, and otherspecial W-CDMA measurements suchas VOX on/off, time synchronizationerror, OBW, transmit power(calculated rms) and out-of-band spu-rious, the analyzers from Advantestcover all relevant W-CDMA measure-ments.

FIG 1 shows the power in the codedomain of a signal with one perchchannel (code 0) and three DPCHs(dedicated physical channels, code16, 32, 64). By analyzing the timedomain power of each individualcode, the power of each pilot, TPC anddata symbol can be evaluated forinstance.

opments. A precondition for their useis digital modulation analysis (option01), which uses DSPs and a fast A/Dconverter for six-fold oversampling(approx. 24 Msample/s). W-CDMAsignals can thus be measured on theuplink or downlink without any con-straint on the number of coded chan-nels (128 with W-CDMA). Digitalmodulation analysis can also be per-formed for QPSK signals provided theyare not spread or coded in a complexway. The same signals can also bemeasured on I/Q baseband inputs(DC to 2.5 MHz/channel).

Using the W-CDMA option, modula-tion analysis can be performed andthe error vector magnitude (EVM), rho,the power of the individual codes and

Articles

News from Rohde& Schwarz Number 163 (1999/III) 17

REFERENCES

[1] Wolf, J.: Signal Analyzer FSIQ – The idealanalyzer for the third mobile-radio gener-ation. News from Rohde& Schwarz (1998)No. 160, pp 4–6

[2] Wolf, J.: Spectrum Analyzer FSEM/FSEK– Fast spectrum analysis now through to40 GHz. News from Rohde & Schwarz(1996) No. 152, pp 7–9

The W-CDMA option allows simulta-neous numeric listing of waveformquality, time alignment error, I/Qorigin offset as well as phase, modu-lation and frequency errors in tabular

FIG 1 Power incode domain ofsignal with oneperch channel(code 0) and threeDPCHs (code 16,32, 64)

Reader service card 163/05 for furtherinformation on Spectrum Analyzers R3267/R3273

Articles

FIG 1 Signal with 15 code channels. One trace shows averagepower measured with rms trace detector, the second peak powerwith peak detector

Center 2.2 GHz 1 s/

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15

10

5

0

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–10

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Ref Lvl15 dB

RBW 10 MHz RF Att 30 dBVBW 10 MHz Mixer –20 dBmSWT 10 s Unit dBm

Delta 1 (T2) 11.78 dB

4.008016 ms

1

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(T2)

–8.74 dBm200.000000 ms

11.78 dB4.008016 ms

form. Graphic presentations such asconstellation diagram, eye pattern,EVM vs time, etc can also be selectedfor either complex-coded or QPSK sig-nals.

Jan Bo Nielsen

Reader service card 163/04 for furtherinformation on Signal Analyzer FSIQ

figures throughout the frequency rangeof the particular analyzer can bedetected. The two programs run underWindows™ on an external computeror under the FSIQ's internal WindowsNT™.

Herbert Schmitt