MC LCPHN I: KHI NIM C BN V MY PHN TCH PH ......................................................................... 3 1. Phn tch ph l g? ..................................................................................................................... 3 2. Min tn s v min thi gian ..................................................................................................... 4 3. Nhng kiu phn tch khc nhau ................................................................................................. 6 B phn tch Fourier ........................................................................................................................ 6 B phn tch qut ............................................................................................................................ 7 Cc bi o thng thng ................................................................................................................. 8 4. Cc thnh phn chnh trong my phn tch ph ......................................................................... 9 4.1. B lc trung tn (IF Filter) ......................................................................................................... 9 4.2. B lc thng thp (Low pass filter (Preselector)) ................................................................... 10 4.3. Detector B nhn dng ng bao...................................................................................... 10 4.4. B lc video ............................................................................................................................ 11 4.5. Preamplifier ............................................................................................................................ 12 Cc thng s k thut quan trng: ................................................................................................ 12 4.1. IF Gain..................................................................................................................................... 12 4.3. phn gii bng thng (RBW) ............................................................................................. 12 4.4. Bng thng video (VBW) ........................................................................................................ 12 4.5. nhy Sensitivity .............................................................................................................. 12 4.6. Noise Figure............................................................................................................................ 13 5. Cch hot ng ca my phn tch ph..................................................................................... 14 PHN II: HNG DN S DNG PSA ................................................................................................. 15 1. Quy trnh bt my...................................................................................................................... 15 Kim tra ......................................................................................................................................... 15 Alignment ...................................................................................................................................... 15 Setup printer ................................................................................................................................. 15 Cc quy nh an ton .................................................................................................................... 16 2. Giao din mt trc v mt sau ................................................................................................ 16 Nt bm mt trc: ....................................................................................................................... 16 Thng bo li ca my................................................................................................................... 19 3. Cc bi o thng hay s dng ................................................................................................. 20 1

o chim dng ph tn ( Occupied Bandwidth OBW) .......................................................... 20 PHN III: HNG DN S DNG MXA............................................................................................... 21 1. c im mt trc ................................................................................................................... 21 2. Ghi ch v hin th ..................................................................................................................... 26 3. c im mt sau ...................................................................................................................... 29 4. Thit lp v ch khi s dng my ............................................................................................ 31 Thit lp kt ni vi my in ............................................................................................................ 31 Ch v an tan khi s dng my MXA ........................................................................................ 31 5. Cc bi o thng dng ............................................................................................................ 33 Php o tc iu ch ca tn hiu AM (Modulation rate) ........................................................ 33 o chim dng ph tn ............................................................................................................ 35 o tn s........................................................................................................................................ 36

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PHN I: KHI NIM C BN V MY PHN TCH PH1. Phn tch ph l g?

thit k, ch to hoc sa cha/ bo dng ti hin trng nhng thit b tn s hoc h thng rf, hc vin cn phi c cng c, thit b gip cho vic phn tch tn hiu truyn qua hoc c truyn i bi h thng hoc thit b ca mnh. Vi vic ph}n tch c tnh ca tn hiu, hc vin c th x|c nh c ng c tnh ca tn hiu t pht hin li v khc phc s c. Vy lm th n{o c th o c nhng tn hiu v tuyn n{y xem iu g s xy ra khi tn hiu i qua mt h thng hoc mt thit b nhm s x|c nh c tnh ca tn hiu? Cu tr li cho vn ny l mt thit b thu th ng, mt thit b s khng gy nh hng ti bt k tham s no ca tn hiu, m ch hin th tn hiu v c th phn tch mt cch d dng. Thit b n{y c gi l my phn tch ph. Nhng my phn tch ph lun lun hin th nhng thng3

tin tn hiu cha c x l nh: in p, cng sut, chu k, dng sng, di bin v tn s. Ty thuc vo nhng ng dng, tn hiu c th c nhng c im khc nhau. in hnh l trong truyn thng, gi thng tin nh ting ni hoc d liu, tn hiu cn phi c iu ch trn sng mang tn s cao. Tn hiu c iu ch s c nhng c tnh k thut ph thuc vo dng iu ch c s dng. Khi tin hnh kim nghim nhng thit b phi tuyn tnh nh b khuch i hoc b trn, k thut vin cn hiu cch to nhng tn hiu mo v dng tn hiu mo nh th no, t hiu c c tnh nhiu v quan st nhng tn hiu nhiu; so snh vi nhng dng tn hiu khc nh th no s gip hc vin trong vic phn tch h thng v thit b ca mnh. Nm c tt c cc dng tn hiu s gip cho hc vin thc hin php o chnh xc hn v chc chn hn trong vic gii thch kt qu. 2. Min tn s v min thi gian

Hnh nh th hin min tn s v min thi gian

4

Theo cch thng thng, khi hc vin mun quan st mt tn hiu in, thng phi s dng mt my hin sng quan st tn hiu bin i theo thi gian. Bin php ny em li thng tin rt quan trng, tuy nhin, n khng hin th ton b nhng thng tin ca tn hiu. hiu ho{n to{n c c tnh ca thit b/ h thng, hc vin cn phi phn tch tn hiu trong min tn s. My phn tch ph phn tch tn hiu theo min tn s cng nh my hin sng phn tch min thi gian. ( iu ng lu }y l{ m|y ph}n tch ph c th c s dng ch iu hng c nh (di 0) thc hin kh nng o min thi gian nh mt my hin sng) Hnh miu t bn trn biu din tn hiu c min thi gian v min tn s. Trong min thi gian, tt c cc thnh phn tn s ca tn hiu c ly tng li v hin th. Trong min tn s, nhng tn hiu phc tp c phn chia thnh nhng thnh phn tn s ca chng, v mc mi di tn s c hin th. Nhng php o min tn s c mt vi u im ring bit. Chng hn khi quan st mt tn hiu dng sin trn my hin sng,hay l tn hiu dng sin khng c mo dng sng hi. Nu quan st tn hiu trn my phn tch ph, hc vin c th thy rng tn hiu thc s c to ra bi nhiu tn s. Nhng g khng quan s|t c trn my hin sng s tr nn r rng hn trn my phn tch ph. Mt vi h thng vn ~ c nh hng min tn s. Chng hn nh nhiu h thng vin thng s dng c|i c gi l FDMA (Frequency Division Multiple Access) hoc FDM (Frequency Division Multiplexing). Trong nhng h thng ny, nhng ngi s dng kh|c nhau c gn cho nhng tn s khc nhau truyn hoc nhn tn hiu, in hnh l mng in thoi. Trm v tuyn cng s dng FDM, vi mi trm mt vng a l x|c nh s chim mt di tn ring bit.

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3. Nhng kiu phn tch khc nhau C 2 cch c bn thc hin php o trn min tn s: bin i Fourier v iu chnh qut. B phn tch Fourier

B phn tch Fourier thc hin vi php o tn hiu trn min thi gian, ri rc ha bng cch ly mu ri rc v{ sau thc hin c|c php to|n bin i tn hiu sang min tn s, sau hin th ph kt qu. Vi kh nng ph}n tch tn hiu thi gian thc, b phn tch Fourier c th ly mu tng chu k mt cch ngu nhin v{ qu| trnh qu| . N cng ci thin tc mt c|ch |ng k hn b phn tch qut truyn thng v c th o pha cng nh ln. Tuy vy, bt k m|y n{o cng c gii hn ca n, nht l v di tn s, nhy v di ng. B ph}n tch Fourier ang tr nn thng dng cng nh b chuyn i tng t - s (ADC) v cng ngh tin tin x l tn hiu s (DSP).

6

B phn tch qut

Loi thit b phn tch ph ph bin nht hin nay l{ m|y thu iu chnh qut. N l thit b c s dng rng ri, v l cng c vi cng dng y cho nhng php o trong min tn s. Cng c ng dng rng ri nht l my thu i tng. My to phch l mt my phi hp 2 sng tn s khc bit to thnh sng hiu tn. V c bn, nhng my phn tch ny qut qua nhng di tn s lin quan v hin th tt c cc thnh phn tn s hin ti. My phn tch iu chnh qut lm vic nh m|y thu thanh AM, a s s iu chnh v thay cho hin th th my thu s pht ra m thanh. Phng php b thu qut c kh nng thc hin nhng php o trn min tn s vi di ng ln v di tn s rng, do tin li cho nhng phn tch tn hiu trn min tn s trong nhiu ng dng, bao gm sn xut, bo dng cho nhng kt ni truyn thng sng ngn, ra a, dng c vin thng, h thng cp ti vi, v nhng dng c qung b, h thng truyn thng di ng, kim tra chn o|n h thng nhiu cm ng in t, kim tra thnh phn, v gim st tn hiu.7

Cc bi o thng thng

Nhng php o quan trng chung nht ca my phn tch ph l{: iu ch, mo v nhiu tn hiu. Vic o cht lng tn hiu iu ch l rt quan trng m bo chc rng h thng lm vic ng v{ thng tin c truyn i l{ chnh x|c. Hiu c ni dung ca ph tn hiu l{ iu rt quan trng, c bit l trong truyn thng vi bng thng b gii hn. Nhng bi th nghim nh mc iu ch, bin di bin, cht lng iu ch, bng thng chim dng l nhng v d v php o iu ch ph bin nht. Trong truyn thng, o bin dng mo c tnh quyt nh vi c thit b thu v thit b nhn. mo sng hi u ra ca thit b truyn c th gy nhiu vi nhng di truyn thng khc. B tin khuch i t chc trong mt b thu phi c lp vi tng quan bin iu phng nga tn hiu xuyn m. Nhng php o mo dng ni chung bao gm bin iu xuyn m, sng hi v pht tp nhiu. Trong thc t, nhiu l thng l tn hiu mong mun c o. Vi bt k mt mch tch cc hay mt thit b n{o cng ph|t ra nhiu. Nhng bi th8

nghim nh h s nhiu m v t s tn hiu trn nhiu m l rt quan trng cho hiu sut vn hnh ca thit b. i vi tt c nhng php o ph}n tch ph, iu quan trng l phi hiu cch vn hnh ca my phn tch ph v nhng tnh nng ca my phn tch ph |p ng cho php o ring ca hc vin v nhng bi th nghim quy trnh k thut. iu ny s gip cho hc vin la chn ng m|y ph}n tch cho nhng ng dng ca mnh. 4. Cc thnh phn chnh trong my phn tch ph

Trn y l s cu to ca mt my phn tch ph

4.1. B lc trung tn (IF Filter) B lc IF l 1 b lc thng di, la chn thnh phn tn hiu mong mun sau b mixer v loi b cc thnh phn khc.

9

RBW iu chnh bng thng ca b lc trung tn, do iu chnh phn gii ca my phn tch ph. 4.2. B lc thng thp (Low pass filter (Preselector)) Loi b tn hiu tn s cao, tn hiu khng mong mun vo b mixer.

4.3. Detector B nhn dng ng bao Cc my phn tch ph hin i s dng cng ngh s ( ADC ) x l tn hiu do loi my ny c thm nhiu ch t|ch ng bao : Gm c: 1 i t, 1 in tr v 1 b lc thng thp

-

C tc dng bin i tn hiu qua b lc IF thnh tn hiu hin th hnh nh. i t c tc dng ch cho thnh phn 1 chiu i qua. Cn ch t RBW nh t|ch c 2 tn hiu gn nhau. phn gii ca b lc trung tn IF quyt nh thay i max ca b tch ng bao.

10

-

Envelop detector bm theo s thay i bin nh ca tn hiu qua b lc IF, nhng ko phi l gi tr tc thi(ko c thng tin v phase) => c th s dng nh 1 vn k. 1- Ch : Positive peak detector: thu v hin th gi tr nh ca tn hiu trong khung thi gian 1 chu k bt tn hiu ( trace) Ch ny rt thch hp cho tn hiu sin nhng qu nhy vi nhiu khi khng c tn hiu sin trong tn hiu vo. 2- Ch negative peak detector: tng t nh trn vi gi tr nh nht 3- Ch sample detection: chn v ghi gi tr ca mt im bt k trn tn hiu vo. Ch ny thch hp o gi| tr rms ca nhiu , hoc tn hiu ging nhiu; tuy nhin ch ny s b qua cc gi tr nh ca tn hiu dng xung hoc tn hiu gii hp khi RBW nh hn khong tn s gia cc im ly mu. 4- Ch normal detector mode: thch hp cho c tn hiu v nhiu. L ch kt hp ca ch (1) v (2) Ch ny cho php hin th tt c tn hiu nhiu v khc phc nhc im b qua gi tr nh ca ch sample detection

4.4. B lc video C tc dng lm gim nn nhiu, lm mt tn hiu hin th trn mn hnh L 1 b lc thng thp nm pha sau b lc IF, quyt inh bng thng ca tn hiu video s c lng t ho v hin th mc bin . Bng thng nh hn ca VBW so vi IF s lm cho b lc video ko theo kp s bin i nhanh ca tn hiu li ra IF, ct b v lm mt tn hiu hin th. Khi gim VBW, bin peak-to-peak ca nn nhiu gim i, s gim i n{y l 1 hm ca t s VBW:RBW ch tch sng positive peak, khi: +) VBW>RBW peak-to-peak nn nhiu gn nh ko i +) VBW lm gi t s S/N = > gim nhy ca my. Cc my phn tch ph c thng set att = 0 ti v tr ca DANL. Cc my phn tch mi c b vi x l c kh nng thay i IF gain tng ng vi gi tr u vo att, do mc tn hiu hin th trn mn hnh gi nguyn gi tr khi ta thay i att => iu ny dn n, khi ta tng gi tr att th nn nhiu cng tng theo (IF gain tng ln, khuych i mc nhiu) trong khi mc tn hiu vn gi nguyn => t s S/N b gim => t t s S/N tt nht ta set att = 0.

-

-

-

-

-

4.6. Noise Figure Cc thit b thu thng xc nh c tnh ca my thng qua Noise Figure (NF). Noise Figure c th c nh ngha l suy gim ca t s S/N khi tn hiu c truyn qua 1 thit b. Mc nhiu hin th trn my phn tch ph thay i theo RBW, nu mun xc nh NF ca my phn tch ph ta cn o cng sut nhiu bng thng 1Hz v13

cng sut nhiu thc t li vo 1Hz (vi nhit phng, mt ph cng sut nhiu l -174dBm => cng sut nhiu ti BW 1Hz l -174dBm) NF khng ph thuc vo RBW (tuy mc nhiu hin th trn my phn tch ph s thay i theo RBW) * Ch : NF c ngha lin quan mt thit ti sensitivity, do NF c lp vi RBW nn s c ngha v mt s dng cao hn nhy. NF cn cho ta bit nhy thc t ca my phn tnh ph.

5. Cch hot ng ca my phn tch ph

S nguyn l c bn ca my phn tch ph

Nh vy iu khin my phn tch ph nhng gi tr sau cn c cn nhc: 1- Bng thng phn gii ( RBW) 2- Thi gian qut ( Sweep time) 3- Suy hao u vo ( Input attenuator) 4- Bng thng video ( Video BW)

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PHN II: HNG DN S DNG PSA1. Quy trnh bt my Kim tra Kim tra phin bn ca firmware: Nhn System , More, Show System. Phin bn ca my v s serial s hin ln trn mn hnh.

Alignment Mi ln bt my phn tch ph ( MPTP) ln, my s t ng chy quy trnh hiu chnh trong. Mi MPTP s c c{i t ch t ng hiu chnh nu my chy lin tc hn 24 gi hoc nhit bn ngai thay i +/- 3oC Setup printer My PSA c th c ni vi my in. Cc chun lin lc vi m|y in c h tr l PCL3 v PCL5. ni my PSA vi my in cn c cp ni my in chun IEEE 1284. Phn ln model my in HP s c h tr bi PSA. Bng k chi tit v c|c model m|y in c h tr c trnh by ti liu E4440- Getting started guide (trang 19 ) Ni my in v setup 1. Tt c my in v PSA 2. Ni my in v PSA s dng cp ni my in chun IEEE 1284. Cng ni my in nm mt sau ca my PSA 3. Bt c 2 thit b ln 4. Trn mt trc ca my PSA nhn PRINT SETUP 5. Chn ngn ng ca my in (trong trng hp ny l Ting Anh) 6. Kim tra kt ni vi my in 7. Nhn phm PRINT trn mt trc ca PSA. Nu my in sn sng v kt ni vi PSA c thit lp ng th m|y in s hot ng bnh thng.15

Trong trng hp li Printer not responding tc l thit lp my in khng ng v ngi s dng cn kim tra li.

Cc quy nh an ton

1.1.1. Quy nh v vn chuyn v ni cp Mt s quy nh gip bo v m|y i vi tnh in : Trc khi ni c|p ng trc vi my phn tch ngi s dng phi ni li ng v v c|p kh tnh in. Ngi s dng my phi eo vng tay chng tnh in trc khi chm v{o li ng ca cp hoc tho bt c u cp no t my PSA Ni t m|y PSA chng tnh in Khi vn chuyn , ct gi cc ph kin trong ti chng tnh in trnh hng hc do tnh in

1.1.2. Quy nh v ngng an tan khi o Mc cng sut vo ti a: +30 dBm (1W) Mc cng sut nh ca tn hiu dng xung ti a: +50 dBm ( rng xung: < 10us , Chu k < 1% v{ suy hao u vo > 30 dB) in p DC: DC coupled < +/- 0.2 Vdc in |p AC: AC coupled +/- 100 Vdc

2. Giao din mt trc v mt sau Nt bm mt trc: Center Freq: Chn tn s trung tm Span: iu chnh di tn s. Gi tr t 10.000 Hz ti 10.000 MHz ( phn gii 1Hz) , ty thuc vo gi tr Res BW. Scale/ Div, Ref Position, Scale Coupling : ch c tc dng trong ch hin th dng sng IQ ( IQ waveform)16

Menu: MEASURE Spectrum (Min tn s): o nhng gi tr trong min tn s Gin ph vi li semi-log v gin dng sng I/Q vi li tuyn tnh Waveform (Min thi gian): o nhng gi tr trong min thi gian: Gin ng bao tn hiu vi li semi log v d liu v tn hiu. Gin dng sng I/Q v d liu thng k CCDF: o d liu thng k v cng sut: ng CCDF bn phi mn hnh Cng sut trung bnh v d liu thng k v cng sut bn tri mn hnh Menu: Meas Control Restart: lp li qu| trnh o ( gi nguyn thit lp trn my) Measure: chuyn ch gia Single v Cont Pause: Dng quy trnh o cho n khi ngi s dng tip tc o

17

2.1.1. Gii thch cc nt bm mt trc my: 1. Nt tt bt 2. Frequency channel: t tn s trung tm ca thit b theo n v Hz, kHz, MHz, Ghz. 3. Mode thay i tnh nng o ca my phn tch ph 4. Mode setup thit lp tt c cc thng s lin quan ti c|c php o trong ch 5. MEASURE v{o menu o thng s tn hiu 6. Meas setup vo menu cha cc thng s o cho b{i o hin hnh 7. Restart : lp li b{i o 8. Data entry: B{n phm dng nhp thit lp , thng s v cc gi tr 9. Phm chn menu mm18

10. Return : thot ra menu hin hnh v quay li menu ngi s dng truy cp gn nht. 2.1.2. Cu trc Menu: Cu trc tan b Menu nm trong USER GUIDE ca thit b E4440 ( trang 253 264) Thng bo li ca my Trong qu trnh s dng my thng bo li c lu ca s lu li ( Nhn System, Show Errors) * Nhng li thng thng gm c: 340 Calibration failed

Thit b yu cu c hiu chnh li. ( Nhn System, Alignments, Align All Now) 222 Data out of range Mt bin hp l c chuyn n b phn trong my tuy nhin bin ny khng th c x l do gi tr ca bin nm ngai di gi tr c nh ngha trong thit b. Hu qu l kt qu o hin trn mn hnh s b gii hn. 129 Meas Uncal

Kt qu o khi m|y cha t hiu chun , thng th li ny c nguyn nhn t vic qut RBW di hp qu nhanh. Kim tra thi gian qut, di o v{ thit lp bng thng hoc nhn phm Auto Couple. Danh sch li y ca my PSA Functional test and message error (trang 33 100)

19

3. Cc bi o thng hay s dng o chim dng ph tn ( Occupied Bandwidth OBW) Quy trnh o: Nhn Meas, Occupied BW chim dng ph tn ly tch phn cng sut ca di tn c hin th v{ t marrker v tr m gia 2 marker s cha mt s % cng sut ca di tn. Gi tr n{y c mc nh l 99% cng sut ca di tn. i vi trng hp mc nh marker s c t sao cho 99% cng sut ca ph tn s nm trong 2 marker v 1 % cng sut ca ph tn s nm ngai marker. Ngi s dng phi thit lp nhng gi tr sau: tn s trung tm, mc tham chiu v khong tch knh.

Hnh minh ha giao din o mc chim dng ph tn

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PHN III: HNG DN S DNG MXA1. c im mt trc

TT

Tn phm

Miu t Nm bn tri bng nt iu khin, c chc nng

1

Menu

x|c nh nhng chc nng hin hnh ca tng phm. Nhm nt ny s dng c{i t cc thng s

2

Analyzer Setup

s dng cho vic thc hin c|c php o trong Mode v Measurement hin hnh. Nhm nt ny chn Mode, v Measurement bn

3

Measurement

trong cc ch . Nhm nt n{y cng c s dng iu khin vic khi to cng nh tn sut ca c|c php o.

4

Marker

Markers (|nh du) thng c s dng trong c|c php o, dng o c|c c tnh im/ on21

ca d liu bn trong di o d liu hin hnh. Nhm nt n{y iu khin nhng chc nng m rng hn ca h thng nh: Thng tin cu hnh m|y v{ c{i t 5 Utility vo/ ra C{i t my in v in Qun l tp tin, lu v gi li Thit lp trc thit b 6 Probe Power Ngun cung cp cho c|c u o tn s cao bn ngoi v cc ph kin. c s dng nghe bt k m thanh no u ra S dng nt n{y xa nhng c tnh trc khi 8 Back Space thng tin c nhp v{o. N cng c s dng nh nt Back trong phn Help v Explorer windows. 9 Delete c s dng xa tp tin hoc thc hin nhng nhim v cn xa khc. Cng USB chun 2.0, loi A. c s dng kt 10 USB Connectors ni vi cc thit b ngoi vi nh chut, bn phm, DVD hoc cng. Nu bn ang trong ch iu khin t xa, nt Local s c tc dng: 11 Local/ Cancel/ (Esc) Tr li chc nng iu khin thit b khi ang xa v iu khin cc b (mt trc) Bt hin th (nu m{n hnh c tt bi22

7

Headphones Output

iu khin t xa) c s dng xa cc li (n ln u s quay tr li ch iu khin cc b v khi n ln th 2 s xa cc dng bo li) Nu bn vn cha n nhm nt ny hoc Enter, nt Cancel s thot ra khi cc chc nng c la chn hin h{nh m{ khng l{m thay i gi tr. Nt Esc hot ng ging nh trn bn phm ca my tnh: Thot ra khi nhng hp thoi Windows Xa li Hy b vic in Thot ra khi qu trnh hot ng Kt ni vi u vo l tn hiu bn ngoi. Phi 12 RF Input m bo rng tng cng sut ca tt c cc tn hiu u vo ca my phn tch khng vc qu + 30 dBm (1 W) Nhp vo 1 gi tr s ring cho chc nng hin 13 Numeric hnh. Mc cn nhp s xut hin pha trn cng bn tri ca mn hnh hin th, trong vng cc thng tin php o. Nt Enter hon thnh vic nhp d liu vo. 14 Enter and Arrow Nt Arrow: Tng hoc gim gi tr ca php o hin hnh

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Di chuyn cc phn cn h tr Di chuyn, thc hin la chn bn trong hp thoi Windows Di chuyn bn trong biu mu c s dng cho vic c{i t c|c php o i chuyn bn trong cc bng

Ghi ch: Nt Arrow khng th s dng dch chuyn con tr quanh mn hnh. Nt Alt hot ng ging nh trn bn phm my 15 Menu/ (Alt) tnh, c dng thay i im iu khin trong trnh n Windows Nt Ctrl hot ng ging nh trn bn phm my 16 Ctrl tnh, c s dng di chuyn nhng ng dng Windows hoc chn nhiu mc trong danh sch. 17 Select/ Space 18 Tab c s dng la chn. c s dng dch chuyn gia cc trng d liu trong hp thoi Windows Tng hoc gim gi tr ca chc nng hot ng hin hnh. Thot ra khi trnh n chnh v quay tr li trnh n trc. S dng phng to ton mn hnh v khi n 21 Full Screen thm 1 ln na s khi phc li trng thi hin th bnh thng.

19 Knob

20 Return

24

22 Help

Khi ng vic tr gip theo hon cnh i vi Mode hin hnh. S dng tng, gim m lng ca loa hoc tt m. Nhm nt ny la chn gia nhng hin th 1

23 Speaker Control

24 Window Control

hoc nhiu ca s. C th phng to ca s hin h{nh hin th y d liu hoc thay i ca s c chn hin hnh. c s dng bt m|y ph}n tch. n xanh

25 Power Standby/ On

hin th ngun ~ c bt, n v{ng hin th ch ch.

26 Input 27 28 29 Input Input Input

Cng vo cho knh khi ch vi sai. Cng v{o cho u vi sai Cng v{o cho u khi ch vi sai Cng v{o cho u khi khng ch n hoc vi sai. Cng ra cho vic hiu chun c|c u vo , , , v{ c|c u o c s dng vi u vo ny. khi khng ch n hoc

30 Cal Out

25

2. Ghi ch v hin th

TT

Phm chc nng

Miu t Thanh hin th c|c php o biu din nhng c{i t php o chung nht v thng tin. Mt v{i php o b gii hn nn d liu c kim tra cho. Hin th Pass/ Fail s hin th pha di bn tri thanh hin th php o.

1

Tt c cc phm trong phn Analyzer Setup mt trc

2

Chc nng ch ng (thanh hin th php o) khi chc nng ch ng hin hnh26

c t 1 gi tr, n s hin th }y. 3 Mode Biu ng - hin th tn ca ng dng c chn v ang chy. Tn php o hin th thng tin tiu 4 Meas View/ Display, Display, Title cho php o hin hnh hoc tiu m ngi s dng to ra thc hin php o. Bng c{i t hin th thng tin h thng: Trng thi u ra/ u vo hin th LXI xanh khi LAN c kt ni. RLTS hin th Remote, Listen, Talk, SRQ. 5 Local v System, I/O Config Tr kh|ng u vo v b ghp. Trng thi hiu chnh bin La chn tham chiu ngoi C{i t chng trnh con hiu chnh ngoi t ng 6 7 Marker System, Control Panel Trace/ Detector, Clear Write (W) Trace Average (A) Max Hold (M) Min Hold (m) 8 Trace/ Detector, More, Detector,27

Kch hot tn s, bin v gi tr hm marker. Bng c{i t hin th ngy v thi gian.

Thng tin v b d v ghi d liu.

Average (A) Normal (N) Peak (P) Sample (S) Negative Peak (P) 9 Phm mm Nh~n phm thay i da trn nt n hin hnh. Hin th thng tin, thng bo cnh bo v li. Nhng c{i t php o cho d liu hin h{nh c hin th trong vng c vch chia.

10

System, Show, Error

11

Phm trong phn Analyzer Setup ca mt trc

28

3. c im mt sau

TT 1

Tn u vo tham chiu ngoi

Miu t u vo cho tn hiu tham chiu tn s ngoi: 1 50 MHz Kt ni GPIB (General Purpose Interface

2

GPIB

Bus) c s dng i vi trng hp thc hin phn tch t xa. Cng USB 2.0, loi B. USB TMC (Test and measurement class) kt ni ti b iu khin

3

Kt ni USB

PC ngo{i iu khin thit b v dnh cho vic chuyn i d liu vi kt ni trn 480 Mbps. Chun USB 2.0, loi A. Kt ni vi thit b

4

C|c u kt ni USB

ngoi vi nh chut, bn phm, my in, DVD, cng.

5

Mn hnh

Cho php nhng kt ni ca mn hnh VGA ngoi.29

6 7 8 9

LAN u vo ngun cng di ng Knh truyn s

Giao din TCP/ IP c s dng cho vic vn hnh phn tch t xa. Kt ni vi ngun xoay chiu. Theo chun. Dnh ring cho vic s dng sau ny.

10 u ra tng t u ra trigger c s dng ng b ha 11 u ra trigger 2 nhng dng c th nghim khc vi my phn tch u ra trigger c s dng ng b ha 12 u ra trigger 1 nhng dng c th nghim khc vi my phn tch 13 Sync 14 u vo trigger 2 Dnh ring cho vic s dng sau ny. Thc hin kch hot ngoi ca nhng php o. Thc hin kch hot ngoi ca nhng php o. S dng vi ngun nhiu 346A, 346B v 346C Agilent. S dng vi ngun nhiu N4000A, N4001A, N4002A. u ra ca my phn tch vi tn hiu tham 18 u ra 10 MHz chiu ngoi tn s 10 MHz. Thng c s dng kha tham chiu tn s ca nhng30

15 u vo trigger 1 B iu khin ngun nhiu + 28 V

16

17 Ngun nhiu nhm SNS

dng c th nghim kh|c n my phn tch. 19 u ra iu chnh chn trc 20 u ra Aux IF Dnh ring cho vic s dng sau ny.

4. Thit lp v ch khi s dng my Thit lp kt ni vi my in My MXA s dng h iu h{nh Microsoft Windows XP do kt ni vi my in ngi s dng cn copy driver ca my in vo h thng ( cn ch bo v h iu hnh khi virus ) v kt ni my in qua chun USB tiu chun. Ch v an tan khi s dng my MXA 4.1.1. Ngng tn hiu vo an tan: Cng sut vo trung bnh ln nht: + 30 dBm ( 1W) in p DC ln nht: +/- 0.2 Vdc in p AC ln nht: +/- 70 Vdc 4.1.2. Bo tr my MXA: C|c u ni ca cp RF cn c lau sch bng cn ( ngun cp cho MXA phi c ngt trc khi lau chi) Sau khi lau chi bng cn cn my ni tho|ng cn bay hi han tan trc khi bt my ln v s dng. Bn trong my MXA c 01 pin LiThi trn bng mch CPU. Trong trng hp pin ny ht hn s dng, ngi s dng khng c t thay th bng pin khc m phi a my MXA quay li trung tm bo tr c thay th loi pin thch hp c Agilent cung cp. 4.1.3. Bo v my khi tnh in: Trc khi ni c|p ng trc vi my phn tch ngi s dng phi ni li ng v v c|p kh tnh in.

31

Ngi s dng my phi eo vng tay chng tnh in trc khi chm v{o li ng ca cp hoc tho bt c u cp no t my PSA Ni t m|y PSA chng tnh in Khi vn chuyn , ct gi cc ph kin trong ti chng tnh in trnh hng hc do tnh in

32

5. Cc bi o thng dng Php o tc iu ch ca tn hiu AM (Modulation rate) B1: Kt ni ngun tn hiu RF n u vo b phn tch RF

B2: Chn ch Chn Mode my phn tch ph. B3: Thit lp my phn tch n Mode Preset.

B4: Thit lp tn s trung tm, di o, ph}n gii bng thng v{ thi gian qut n FREQ Channel, Center Freq, 300, MHz. n SPAN X Scale, Span, 500, kHz. n BW, Res BW, 30, kHz. n Sweep/ Control, Sweep Time, 20, ms.

B5: Thay i t l Y thnh tuyn tnh n AMPTD Y Scale, Scale Type (Lin) B6: nh v nh tn hiu n AMPTD Y Scale, Ref Level (vn nm xoay mt trc)

B7: Thit lp my phn tch im gc 0 thc hin php o trn min thi gian n SPAN X Scale, Zero Span n Sweep/ Control, Sweep Time, 5, ms

B8: S dng b trigger hnh nh n nh vic theo di33

-

n Trigger, Video

B9: o tc AM s dng delta markers n Peak Search, Marker Delta, Next Right hoc Next Left.

Lu : Cn m bo delta markers trn c t nhng nh gn k. Tn s hoc tc iu ch s l: AM rate = = 1 kHz

B phn tch tn hiu cng thc hin hiu chun tc ny bng cch thay i marker hin th thi gian nghch o. n Marker, Properties, X Axis Scale, Inverse Time.

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o chim dng ph tn Xa ht cc thit lp t trc : Nhn Mode Preset Chn tiu chun tn hiu Mode setup: Nhn Mode setup, Radio Std, 3GPP W-CDMA, 3GPP W-CDMA , Device t tn s trung tm : Nhn Freq Channel Nhn Meas, Occupied BW

Kt qu trn mn hnh s tng t hnh sau:

35

o tn s Ch t ng: Kt ni my MXA vi ngun tn hiu. Nhn Auto Tune trn mt trc ca my. Nhn Marker trn mt trc ca my , Nhn Peak Search trn menu mm. Trong trng hp tn hiu u vo c bit r ( tn s, cng sut ) MXA c th c iu khin bng tay t di bin : t di tn s: tn s GHz ) t di o : Tm tn hiu bng marker: Nhn SPAN, chn gi tr thch hp , chn n v thch hp Nhn Peak search. Nhn AMPTD Y Scale , chn bin thch hp , chn n v ( dBm) Nhn Freq Channel, Center Freq, chn thch hp, chn n v ( Hz, MHz ,

36