FMUSER RF Power Amplifier Voltage Test Bench ya AM Transmitter Power Amplifier (PA) ndi Buffer Amplifier Testing

RF Power Amplifier Board Testing | AM Commissioning Solution kuchokera ku FMUSER

 

Ma RF magetsi amplifiers ndi ma buffer amplifiers ndi mbali zofunika kwambiri za ma transmitters a AM ndipo nthawi zonse amatenga gawo lofunikira pakupanga koyambirira, kutumiza, ndi kukonza pambuyo pake.

 

Zigawo zoyambira izi zimathandizira kutumiza kolondola kwa ma siginecha a RF. Kutengera mulingo wamagetsi ndi mphamvu zomwe wolandila amafunikira kuti adziwe ndikuzindikira chizindikirocho, kuwonongeka kulikonse kumatha kusiya ma transmitter akusokoneza ma siginecha, kuchepetsa kugwiritsa ntchito mphamvu, ndi zina zambiri.

 

 

Pakukonzanso pambuyo pake ndikukonza zigawo zikuluzikulu za ma transmitters, zida zina zofunika zoyesera ndizofunikira. Yankho la FMUSER la RF muyeso limakuthandizani kutsimikizira kapangidwe kanu pogwiritsa ntchito muyeso wosayerekezeka wa RF.

 

Momwe ntchito

 

Amagwiritsidwa ntchito makamaka poyesa pomwe board amplifier yamagetsi ndi buffer amplifier board ya AM transmitter siyingatsimikizidwe ikakonzedwa.

 

 

Mawonekedwe

 

• Mphamvu ya benchi yoyeserera ndi AC220V, ndipo gululi lili ndi chosinthira mphamvu. Zomwe zimapangidwa mkati -5v, 40v, ndi 30v zimaperekedwa ndi magetsi osinthika omangidwa.
• Pali ma buffer test test Q9 yolumikizira kumtunda kwa benchi yoyeserera: J1 ndi J2, mayeso amphamvu amplifier zotulutsa Q9: J1 ndi J2, ndi chizindikiro chamagetsi amplifier (59C23). J1 ndi J2 amalumikizidwa ndi oscilloscope yophatikizika kawiri.
• Mbali yakumanzere ya kumunsi kwa benchi yoyeserera ndi malo oyesera a buffer amplification, ndipo kumanja ndi mayeso a board amplifier.

 

malangizo

 

• J1: Yesani chosinthira mphamvu
• S1: Mayeso a board a Amplifier ndi chosinthira chosankha cha buffer board
• S3 / S4: Kuyesa kwa board ya amplifier kumanzere ndi kumanja kuyatsa kapena kuzimitsa kusankha.

 

RF Power Amplifier: ndi chiyani komanso momwe imagwirira ntchito?

 

Pawayilesi, RF power amplifier (RF PA), kapena radio frequency power amplifier ndi chipangizo chamagetsi chodziwika bwino chomwe chimagwiritsidwa ntchito kukulitsa ndi kutulutsa zomwe zimalowetsedwa, zomwe nthawi zambiri zimawonetsedwa ngati magetsi kapena mphamvu, pomwe ntchito ya RF Power amplifier ndikukweza. zinthu zomwe "zimatengera" kumlingo wina ndi "kutumiza kudziko lakunja."

 

Zimagwira bwanji?

 

Nthawi zambiri, amplifier yamagetsi ya RF imapangidwa mu transmitter mu mawonekedwe a board board. Zachidziwikire, chowonjezera chamagetsi cha RF chingakhalenso chida chosiyana cholumikizidwa ndi chotulutsa champhamvu chotsika kudzera pa chingwe cha coaxial. Chifukwa cha malo ochepa, ngati mukufuna, olandiridwa Kusiya ndemanga ndipo ndidzasintha tsiku lina mtsogolo :).

 

Kufunika kwa amplifier ya RF ndiko kupeza mphamvu yokwanira yotulutsa RF. Izi ndichifukwa choti, choyamba, kumapeto kwa gawo lakutsogolo kwa chowulutsira, chizindikiro cha audio chikalowetsedwa kuchokera ku chipangizo chomvera kudzera pamzere wa data, chimasinthidwa kukhala chizindikiro chofooka kwambiri cha RF kudzera mukusintha, koma izi zofooka. zizindikiro sizokwanira kuti zigwirizane ndi kuwulutsa kwakukulu. Chifukwa chake, ma siginecha osinthidwa a RFwa amadutsa mumndandanda wamakulitsidwe (gawo la buffer, siteji yokulitsa yapakatikati, gawo lokulitsa mphamvu) kudzera pa RF magetsi amplifier mpaka atakulitsidwa kukhala mphamvu yokwanira kenako ndikudutsa pamaneti ofananira. Pomaliza, imatha kudyetsedwa ku mlongoti ndikutuluka.

 

Pa ntchito yolandila, gawo la transceiver kapena transmitter-receiver litha kukhala ndi chosinthira chamkati kapena chakunja / cholandila (T/R). Ntchito ya T/R switch ndikusintha mlongoti kupita ku transmitter kapena wolandila ngati pakufunika.

 

Kodi Basic Structure ya RF Power Amplifier ndi chiyani?

 

Zizindikiro zazikulu zaukadaulo zama RF amplifiers ndi mphamvu zotulutsa komanso kuchita bwino. Momwe mungasinthire mphamvu zotulutsa ndikuchita bwino ndiye maziko a zolinga zamapangidwe a RF amplifiers.

 

RF power amplifier imakhala ndi ma frequency ogwiritsira ntchito, ndipo ma frequency osankhidwa omwe amasankhidwa ayenera kukhala mkati mwa ma frequency ake. Pamagwiritsidwe pafupipafupi a 150 megahertz (MHz), amplifier yamagetsi ya RF yapakati pa 145 mpaka 155 MHz ingakhale yoyenera. RF power amplifier yokhala ndi ma frequency osiyanasiyana a 165 mpaka 175 MHz sidzatha kugwira ntchito pa 150 MHz.

 

Nthawi zambiri, mu RF magetsi amplifier, ma frequency oyambira kapena ma harmonic amatha kusankhidwa ndi LC resonant circuit kuti akwaniritse kukulitsa kosasokoneza. Kuphatikiza pa izi, zigawo za harmonic zomwe zimatuluka ziyenera kukhala zazing'ono momwe zingathere kuti zisasokonezedwe ndi njira zina.

 

Mabwalo amagetsi amagetsi a RF amatha kugwiritsa ntchito ma transistors kapena mabwalo ophatikizika kuti apange kukulitsa. Pamapangidwe amagetsi amagetsi a RF, cholinga chake ndikukhala ndi matalikidwe okwanira kuti apange mphamvu yotulutsa yomwe mukufuna, ndikuloleza kusagwirizana kwakanthawi komanso kakang'ono pakati pa chowulutsira ndi mlongoti wodyetsa ndi mlongoti womwewo. Kulepheretsa kwa chodyetsa mlongoti ndi mlongoti womwewo nthawi zambiri ndi 50 ohms.

 

Momwemo, kuphatikiza kwa mlongoti ndi mzere wa chakudya kudzawonetsa kutsekereza kokhazikika pama frequency ogwiritsira ntchito.

Chifukwa chiyani RF Power Amplifier ndiyofunikira?

 

Monga gawo lalikulu la makina otumizira, kufunikira kwa amplifier yamagetsi a RF kumawonekera. Tonse tikudziwa kuti wofalitsa waukadaulo nthawi zambiri amakhala ndi magawo awa:

 

1. Chigoba cholimba: nthawi zambiri chimapangidwa ndi aluminium alloy, mtengo wake ndi wapamwamba.
2. Bolodi lolowera mawu: lomwe limagwiritsidwa ntchito makamaka kupeza ma signature kuchokera kugwero la mawu, ndikulumikiza chowulutsira ndi gwero la mawu ndi chingwe chomvera (monga XLR, 3.45MM, ndi zina). Bolodi yolowetsa mawu nthawi zambiri imayikidwa pagawo lakumbuyo la chowulutsira ndipo imakhala yofanana ndi makona anayi okhala ndi chiyerekezo cha pafupifupi 4: 1.
3. Magetsi: Amagwiritsidwa ntchito popereka mphamvu. Mayiko osiyanasiyana ali ndi magetsi osiyanasiyana, monga 110V, 220V, etc. M'malo ena akuluakulu a wailesi, magetsi omwe amagwiritsidwa ntchito ndi 3 Phase 4 Wire System (380V / 50Hz) malinga ndi muyezo. Ndi malo opangira mafakitale malinga ndi muyezo, womwe ndi wosiyana ndi muyezo wamagetsi wamba.
4. Gulu lowongolera ndi modulator: nthawi zambiri imakhala pamalo owoneka bwino kwambiri kutsogolo kwa ma transmitter, opangidwa ndi gulu loyikirapo ndi makiyi ena ogwira ntchito (knob, makiyi owongolera, skrini yowonetsera, ndi zina), zomwe zimagwiritsidwa ntchito makamaka kutembenuza siginecha yolumikizira mawu. mu chizindikiro cha RF (kukomoka kwambiri).
5. RF mphamvu amplifier: nthawi zambiri amatanthauza gulu la amplifier lamagetsi, lomwe limagwiritsidwa ntchito makamaka kukulitsa kuyika kofooka kwa siginecha ya RF kuchokera pagawo losinthira. Imakhala ndi PCB ndi ma etchings angapo ovuta (monga mizere yolowera ya RF, tchipisi ta amplifier mphamvu, zosefera, ndi zina), ndipo Imalumikizidwa ndi kachitidwe ka antenna feeder kudzera pa mawonekedwe a RF.
6. Magetsi ndi zimakupiza: Zomwe zimapangidwira zimapangidwa ndi wopanga ma transmitter, omwe amagwiritsidwa ntchito kwambiri popangira magetsi komanso kutulutsa kutentha.

 

Pakati pawo, RF mphamvu amplifier ndiye pachimake, okwera mtengo kwambiri, komanso gawo lotentha kwambiri la transmitter, lomwe limatsimikiziridwa makamaka ndi momwe limagwirira ntchito: kutulutsa kwa RF mphamvu amplifier kumalumikizidwa ndi mlongoti wakunja.

 

Ma antennas ambiri amatha kuwongoleredwa kuti akaphatikizidwa ndi chodyetsa, apereke njira yabwino kwambiri yolumikizirana ndi ma transmitter. Kufananitsa koyimitsa kumeneku kumafunika kuti mphamvu zambiri zisamutsidwe kuchokera pa transmitter kupita ku mlongoti. Ma Antennas ali ndi mawonekedwe osiyana pang'ono pama frequency. Kuyesa kofunikira ndikuwonetsetsa kuti mphamvu zowonekera kuchokera ku mlongoti kupita ku chodyetsa ndi kubwerera ku chotumizira ndizochepa mokwanira. Kusokoneza kwa impedance kukakwera kwambiri, mphamvu ya RF yotumizidwa ku mlongoti imatha kubwereranso ku transmitter, ndikupanga kuchuluka kwa mafunde amphamvu (SWR), kupangitsa kuti mphamvu yotumizira ikhalebe mu amplifier yamagetsi ya RF, kuchititsa kutentha kwambiri komanso kuwonongeka kwamphamvu. zigawo.

 

Ngati amplifier ikhoza kukhala ndi ntchito yabwino, ndiye kuti ikhoza kuthandizira kwambiri, yomwe imasonyeza "mtengo" wake, koma ngati pali mavuto ena ndi amplifier, ndiye kuti pambuyo poyambira kugwira ntchito kapena kugwira ntchito kwa nthawi, sikokwanira. motalikira Perekani "chothandizira" chilichonse, koma pangakhale "zododometsa" zosayembekezereka. "Zowopsa" zotere ndizowopsa kudziko lakunja kapena chokulitsa chomwe.

 

Buffer amplifier: ndi chiyani komanso momwe imagwirira ntchito?

 

Ma buffer amplifiers amagwiritsidwa ntchito mu ma transmitters a AM.

 

Transmitter ya AM imakhala ndi siteji ya oscillator, siteji ya buffer ndi yochulukitsa, siteji yoyendetsa, ndi gawo la modulator, pomwe oscillator wamkulu amathandizira buffer amplifier, ndikutsatiridwa ndi siteji ya buffer.

 

Gawo pafupi ndi oscillator limatchedwa buffer kapena buffer amplifier (nthawi zina amangotchedwa buffer) - amatchedwa chifukwa amapatula oscillator ku chokulitsa mphamvu.

 

Malinga ndi Wikipedia, amplifier ya buffer ndi amplifier yomwe imapereka kutembenuka kwamagetsi kuchokera kudera lina kupita ku lina kuti ateteze gwero la siginecha kuchokera kumagetsi aliwonse (kapena magetsi, a buffer) omwe katunduyo angatulutse.

 

M'malo mwake, mbali ya transmitter, amplifier ya buffer imagwiritsidwa ntchito kupatulira oscillator yayikulu ku magawo ena a transmitter, popanda chotchingira, pomwe amplifier yamagetsi isintha, imabwereranso ku oscillator ndikupangitsa kuti isinthe pafupipafupi. ndipo ngati oscillation Ngati transmitter isintha pafupipafupi, wolandila amataya kulumikizana ndi chotumizira ndikulandila zidziwitso zosakwanira.

 

Zimagwira bwanji?

 

Oscillator yayikulu mu transmitter ya AM imapanga ma frequency okhazikika a sub-harmonic carrier. The crystal oscillator imagwiritsidwa ntchito popanga oscillation yokhazikika iyi ya subharmonic. Pambuyo pake, mafupipafupi amawonjezeka kufika pamtengo wofunidwa pogwiritsa ntchito jenereta ya harmonic. Mafupipafupi onyamula ayenera kukhala okhazikika. Kusintha kulikonse kwafupipafupi kumeneku kungayambitse kusokoneza kwa malo ena otumizira mauthenga. Zotsatira zake, wolandirayo amavomereza mapulogalamu kuchokera ku ma transmitters angapo.

 

Ma amplifiers osinthidwa omwe amapereka kulowetsedwa kwakukulu pamafupipafupi a oscillator ndi ma buffer amplifiers. Zimathandiza kupewa kusintha kulikonse kwa katundu wamakono. Chifukwa cha kulowetsedwa kwake kwakukulu pamafupipafupi ogwiritsira ntchito oscillator wamkulu, zosintha sizimakhudza oscillator wamkulu. Chifukwa chake, amplifier amplifier amalekanitsa oscillator wamkulu kuchokera kumagawo ena kuti zotsatira zotsitsa zisasinthe ma frequency a oscillator wamkulu.

 

RF Power Amplifier Test Bench: Zomwe zili ndi momwe zimagwirira ntchito

 

Mawu oti "benchi yoyesera" amagwiritsa ntchito chilankhulo chofotokozera za Hardware pamapangidwe adijito kufotokoza khodi yoyeserera yomwe imayambitsa DUT ndikuyesa mayeso.

 

Mayeso Bench

 

Benchi yoyesera kapena benchi yoyeserera ndi malo omwe amagwiritsidwa ntchito kutsimikizira kulondola kapena kuchita bwino kwa kapangidwe kapena chitsanzo.

 

Mawuwa adachokera pakuyesa zida zamagetsi, pomwe mainjiniya amakhala pa benchi ya labu, kukhala ndi zida zoyezera ndi zowongolera monga ma oscilloscopes, ma multimeter, zitsulo zolumikizira, zodulira mawaya, ndi zina zambiri, ndikutsimikizira pamanja kulondola kwa chipangizocho. (DUT).

 

Pankhani ya mapulogalamu kapena firmware kapena hardware engineering, benchi yoyesera ndi malo omwe mankhwala omwe akupangidwa amayesedwa mothandizidwa ndi mapulogalamu ndi zida za hardware. Nthawi zina, pulogalamuyo ingafunike zosintha zazing'ono kuti zigwire ntchito ndi testbench, koma kukopera mosamalitsa kumatsimikizira kuti zosintha zitha kuthetsedwa mosavuta ndipo palibe nsikidzi zomwe zimayambitsidwa.

 

Tanthauzo lina la "bedi loyesera" ndi malo akutali, olamulidwa, ofanana kwambiri ndi malo opangira zinthu, koma osabisala kapena kuwonekera kwa anthu, makasitomala, ndi zina zotero. Choncho ndizotetezeka kusintha ngati palibe wogwiritsa ntchito mapeto.

 

RF Chipangizo Choyesedwa (DUT)

 

Chida chomwe chikuyesedwa (DUT) ndi chipangizo chomwe chayesedwa kuti chidziwe momwe chimagwirira ntchito komanso luso lake. DUT ikhoza kukhalanso gawo la gawo lalikulu kapena gawo lotchedwa unit under test (UUT). Yang'anani ku DUT kuti muwone zolakwika kuti chipangizocho chikugwira ntchito bwino. Mayesowa adapangidwa kuti aletse zida zowonongeka kuti zifike pamsika, zomwe zingachepetsenso ndalama zopangira.

 

Chida chomwe chikuyesedwa (DUT), chomwe chimatchedwanso kuti chida choyesedwa (EUT) ndi chipangizo chomwe chikuyesedwa (UUT), ndi chowunika chopangidwa chomwe chimayesedwa chikapangidwa koyamba kapena pambuyo pake m'moyo wake monga gawo la kuyesa kosalekeza. ndi calibration. Izi zitha kuphatikiza kuyezetsa pambuyo pokonza kuti muwone ngati malondawo akugwirizana ndi zomwe zidakhazikitsidwa.

 

M'mayeso a semiconductor, chipangizo chomwe chikuyesedwa ndi chofera pawafa kapena gawo lomaliza la phukusi. Pogwiritsa ntchito njira yolumikizira, gwirizanitsani zigawo ndi zida zoyesera zokha kapena zamanja. Zida zoyesera ndiye zimapatsa mphamvu gawolo, zimapereka zidziwitso zokondoweza, ndikuyesa ndikuwunika kutulutsa kwa zida. Mwanjira imeneyi, woyesa amawona ngati chipangizocho chikuyesedwa chikukwaniritsa zofunikira za chipangizocho.

 

Nthawi zambiri, RF DUT ikhoza kukhala mawonekedwe ozungulira ndi kuphatikiza kulikonse ndi kuchuluka kwa analogi ndi zigawo za RF, ma transistors, resistors, capacitors, ndi zina zotero, zoyenera kuyerekeza ndi Agilent Circuit Envelope Simulator. Mabwalo ovuta kwambiri a RF atenga nthawi yochulukirapo kuti ayesere ndikuwononga kukumbukira kwambiri.

 

Nthawi yoyerekeza ya Testbench ndi zofunikira pakukumbukira zitha kuganiziridwa ngati kuphatikiza kwa miyeso yoyezera benchmark ndi zofunikira za RF dera losavuta kuphatikiza ndi zofunikira zoyeserera za RF DUT zachidwi.

 

RF DUT yolumikizidwa ku benchi yoyesera opanda zingwe nthawi zambiri imatha kugwiritsidwa ntchito limodzi ndi benchi yoyesera kuti ipange miyeso yokhazikika pokhazikitsa magawo a benchi yoyeserera. Zokonda zoyezera zokhazikika zilipo pamtundu wa RF DUT:

 

• Chizindikiro cholowetsa (RF) chokhala ndi ma frequency frequency carrier carrier ndichofunikira. Kutulutsa kwa benchi yoyeserera ya RF sipanga siginecha ya RF yomwe ma frequency a RF chonyamulira amasiyana ndi nthawi. Komabe, benchi yoyesera imathandizira chizindikiro chotulutsa chomwe chili ndi gawo la RF chonyamulira komanso kusinthasintha kwafupipafupi, komwe kumatha kuyimiridwa ndi kusintha koyenera kwa ma envulopu a I ndi Q pafupipafupi chonyamulira cha RF.
• Chizindikiro chotulutsa chokhala ndi ma frequency a RF chonyamulira chimapangidwa. Chizindikiro cholowetsa benchi yoyeserera sichiyenera kukhala ndi ma frequency onyamula omwe ma frequency amasiyana pakapita nthawi. Komabe, benchi yoyesera imathandizira ma siginecha omwe ali ndi phokoso la gawo la chonyamulira cha RF kapena kusintha kwa nthawi kwa Doppler kwa chonyamulira cha RF. Zosokoneza zazizindikirozi zikuyembekezeka kuyimiridwa ndi kusintha kwa ma envulopu a I ndi Q pafupipafupi pafupipafupi RF chonyamulira.
• Chizindikiro cholowera kuchokera ku jenereta ya siginecha yokhala ndi 50-ohm source resistance ndiyofunika.
• Chizindikiro cholowera chopanda magalasi amafunikira.
• Pangani chizindikiro chotulutsa chomwe chimafuna chopinga chakunja cha 50 ohms.
• Amapanga chizindikiro chotulutsa popanda spectral mirroring.
• Dalirani pa benchi yoyesera kuti muyesere zofananira za bandpass chizindikiro cha RF DUT chotulutsa chizindikiro.

 

Zoyambira za AM Transmitter Zomwe Muyenera Kudziwa

 

Chotumizira chomwe chimatulutsa chizindikiro cha AM chimatchedwa AM transmitter. Ma transmitterswa amagwiritsidwa ntchito mumayendedwe apakati (MW) ndi ma frequency afupiafupi (SW) akuwulutsa kwa AM. Gulu la MW lili ndi ma frequency pakati pa 550 kHz ndi 1650 kHz ndipo gulu la SW lili ndi ma frequency kuchokera ku 3 MHz mpaka 30 MHz.

 

Mitundu iwiri ya ma transmitters a AM omwe amagwiritsidwa ntchito kutengera mphamvu yotumizira ndi:

 

1. mkulu
2. mlingo wotsika

 

Ma transmitters apamwamba amagwiritsa ntchito kusinthasintha kwapamwamba, ndipo otsika kwambiri amagwiritsa ntchito kusinthasintha kwapamwamba. Kusankha pakati pa ma module awiriwa kumadalira mphamvu yotumizira ya AM transmitter. M'ma transmitters omwe mphamvu zawo zotumizira zitha kukhala pa dongosolo la kilowatts, kusinthasintha kwapamwamba kumagwiritsidwa ntchito. M'ma transmitter amphamvu otsika omwe amangofuna ma watts ochepa a mphamvu zotumizira, kusinthasintha kwapang'onopang'ono kumagwiritsidwa ntchito.

 

Ma transmitter apamwamba komanso otsika

 

Chithunzi chomwe chili pansipa chikuwonetsa chojambula cha block chapamwamba komanso chotsika kwambiri. Kusiyana kwakukulu pakati pa ma transmitters awiriwa ndikukulitsa mphamvu kwa chonyamulira ndi ma siginecha osinthidwa.

 

Chithunzi (a) chikuwonetsa chojambula chamtundu wapamwamba wa AM transmitter.

 

Chithunzi (a) chajambulidwa kuti chitumize mawu. Pakutumiza kwapamwamba, mphamvu ya chonyamulira ndi ma siginecha osinthika imakulitsidwa isanagwiritsidwe ntchito pagawo la modulator, monga momwe tawonetsera pa Chithunzi (a). Pakusinthika kwapang'onopang'ono, mphamvu ya ma siginecha awiri olowera pagawo la modulator simakulitsidwa. Mphamvu yotumizira yofunikira imapezeka pagawo lomaliza la chopatsira, Class C mphamvu amplifier.

 

Magawo a Chithunzi (a) ndi:

 

1. Carrier Oscillator
2. Buffer Amplifier
3. Frequency Multiplier
4. Amplifier Wamphamvu
5. Audio Chain
6. Modulated Class C Power Amplifier
7. Carrier Oscillator

 

Chonyamulira oscillator chimapanga chizindikiro chonyamulira mumayendedwe a wailesi. Mafupipafupi a chonyamulira amakhala okwera nthawi zonse. Popeza ndizovuta kupanga ma frequency apamwamba ndi kukhazikika kwafupipafupi, ma oscillator onyamula amapanga ma submultiples ndi ma frequency omwe amafunidwa. sub-octave iyi imachulukitsidwa ndi gawo lochulukitsa kuti mupeze ma frequency omwe mukufuna. Komanso, crystal oscillator ingagwiritsidwe ntchito panthawiyi kuti ipange chonyamulira chotsika kwambiri chokhala ndi kukhazikika kwafupipafupi. The pafupipafupi multiplier siteji ndiye kumawonjezera chonyamulira pafupipafupi mtengo wake ankafuna.

 

Buffer Amp

 

Cholinga cha buffer amplifier ndi pawiri. Izo poyamba zimagwirizana ndi linanena bungwe impedance wa chonyamulira oscillator ndi athandizira impedance wa pafupipafupi multiplier, gawo lotsatira la chonyamulira oscillator. Kenako amalekanitsa chonyamulira oscillator ndi pafupipafupi multiplier.

 

Izi ndizofunikira kuti chochulukitsa chisakoke mafunde akulu kuchokera ku chonyamulira oscillator. Izi zikachitika, mafupipafupi a oscillator chonyamulira sadzakhala okhazikika.

 

Frequency Multiplier

 

Kuchulukitsa kwapang'onopang'ono kwa chizindikiro chonyamulira chomwe chimapangidwa ndi chonyamulira oscillator tsopano chimagwiritsidwa ntchito kuchulukitsa pafupipafupi kudzera pa buffer amplifier. Gawoli limadziwikanso kuti jenereta ya harmonic. Kuchulukitsa pafupipafupi kumapanga ma harmonics apamwamba a frequency oscillator carrier. Ma frequency multiplier ndi njira yosinthira yomwe imayitanira kufupipafupi komwe kumafunika kufalikira.

 

Mphamvu Amp

 

Mphamvu ya chizindikiro chonyamulira imakwezedwa mu gawo la amplifier mphamvu. Ichi ndi chofunikira chofunikira pa ma transmitter apamwamba kwambiri. Ma amplifiers a Class C amapereka mphamvu zamagetsi zamakono zamtundu wonyamulira pazotulutsa zawo.

Audio Chain

 

Chizindikiro cha audio chomwe chiyenera kuperekedwa chimachokera ku maikolofoni monga momwe tawonetsera pa Chithunzi (a). Makina opangira ma audio amakulitsa mphamvu ya siginecha iyi. Kukulitsa uku ndikofunikira kuti muyendetse ma audio amplifiers. Kenako, chokulitsa mphamvu cha Gulu A kapena Gulu B chimakulitsa mphamvu yamawu.

 

Modulated Class C Amplifier

 

Ili ndiye gawo lotulutsa la chopatsira. Chizindikiro cha audio chosinthidwa ndi chizindikiro chonyamulira chimagwiritsidwa ntchito pagawo losinthikali pambuyo pakukulitsa mphamvu. Kusinthasintha kumachitika panthawiyi. Amplifier ya Class C imakulitsanso mphamvu ya siginecha ya AM ku mphamvu yotumiziranso. Chizindikirochi pamapeto pake chimaperekedwa ku mlongoti, womwe umatulutsa chizindikiro kumalo otumizira.

 

Chithunzi (b): Chojambula cha Block cha Low-Level AM Transmitter Block

 

Chotsitsa chotsika cha AM chomwe chikuwonetsedwa mu Chithunzi (b) chikufanana ndi chotengera chapamwamba kupatula kuti mphamvu ya chonyamulira ndi ma audio simakulitsidwa. Zizindikiro ziwirizi zimagwiritsidwa ntchito molunjika ku Class C mphamvu amplifier.

 

Kusinthasintha kumachitika panthawiyi, ndipo mphamvu ya siginecha yosinthidwa imakulitsidwa kumlingo wofunikira wotumizira. Kenako mlongoti wotumizira umatumiza chizindikiro.

 

Kulumikizana kwa gawo lotulutsa ndi mlongoti

 

Gawo lotulutsa lamagetsi amplifier la kalasi C limadyetsa siginecha ku mlongoti wotumizira. Kusamutsa mphamvu yayikulu kuchokera pagawo lotulutsa kupita ku mlongoti, zopinga za magawo awiriwa ziyenera kufanana. Kwa izi, netiweki yofananira ndiyofunika. Kufanana kwapakati pa ziwirizi kuyenera kukhala koyenera pama frequency onse. Popeza kufananitsa pama frequency osiyanasiyana ndikofunikira, ma inductors ndi ma capacitor omwe amapereka zopinga zosiyanasiyana pama frequency osiyanasiyana amagwiritsidwa ntchito pamaneti wofananira.

 

Netiweki yofananira iyenera kupangidwa pogwiritsa ntchito zida izi. Monga momwe chithunzi (c) chili pansipa.

 

Chithunzi (c): Dual Pi yofananira network

 

Netiweki yofananira yomwe imagwiritsidwa ntchito polumikiza gawo lotulutsa ma transmitter ndipo mlongoti umatchedwa dual π network. Netiweki ikuwonetsedwa mu Chithunzi (c). Zili ndi ma inductors awiri L1 ndi L2 ndi ma capacitors awiri C1 ndi C2. Makhalidwe a zigawozi amasankhidwa kuti kulowetsedwa kwa intaneti pakati pa 1 ndi 1 '. Chithunzi (c) chikuwonetsedwa kuti chifanane ndi kusokoneza kwa gawo lotulutsa ma transmitter. Kuphatikiza apo, kusokoneza kwa netiweki kumafanana ndi kusokoneza kwa mlongoti.

 

Netiweki yofananira iwiri π imasefanso ma frequency osafunikira omwe amawonekera kumapeto kwa gawo lomaliza la transmitter. Kutulutsa mphamvu kwa amplifier ya Class C modulated kumatha kukhala ndi ma harmonics osafunika kwambiri, monga ma harmonics achiwiri ndi achitatu. Kuyankha pafupipafupi kwa netiweki yofananira kumayikidwa kuti kukana kwathunthu ma harmonics osafunikirawa ndipo chizindikiro chokhacho chomwe chimafunidwa chimaphatikizidwa ndi mlongoti.