Apa, mawonekedwe anayi oyambira ma frequency ma wayilesi adzatanthauziridwa kuchokera kuzinthu zinayi: mawonekedwe a ma radio frequency, chizindikiro chaching'ono chofunidwa, chizindikiro chachikulu chosokoneza, ndi kusokoneza njira yoyandikana, ndi zinthu zofunika zomwe zimafunikira chidwi chapadera pakupanga kwa PCB.

Mawonekedwe awayilesi amtundu wa ma radio frequency circuit kayeseleledwe

Ma transmitter opanda zingwe ndi olandila amagawidwa m'magawo awiri: ma frequency frequency ndi ma radio frequency. Ma frequency ofunikira amaphatikiza kuchuluka kwa ma frequency a siginecha yolowera ya transmitter komanso kuchuluka kwa ma frequency a siginecha yotulutsa wolandila. Bandwidth ya ma frequency ofunikira amatsimikizira kuchuluka komwe deta imatha kuyenda mudongosolo. Mafupipafupi oyambira amagwiritsidwa ntchito kuti apititse patsogolo kudalirika kwa mtsinje wa deta ndikuchepetsa katundu woperekedwa ndi transmitter pa sing'anga yopatsirana pansi pa mlingo wapadera wotumizira deta. Chifukwa chake, chidziwitso chochuluka chaukadaulo wamakina chimafunikira popanga ma frequency oyambira pa PCB. Ma frequency a radio frequency a transmitter amatha kutembenuza ndikusinthanso siginecha ya baseband yokonzedwa kukhala kanjira yosankhidwa, ndikulowetsa chizindikirochi munjira yotumizira. M'malo mwake, ma frequency a radio frequency a wolandila amatha kupeza chizindikiro kuchokera pamayendedwe opatsira, ndikusintha ndikuchepetsa ma frequency mpaka ma frequency oyambira.
Transmitter ili ndi zolinga zazikulu ziwiri za mapangidwe a PCB: Choyamba ndikuti ayenera kufalitsa mphamvu inayake pomwe akugwiritsa ntchito mphamvu zochepa kwambiri. Chachiwiri ndi chakuti sangathe kusokoneza ntchito yachibadwa ya ma transceivers mumayendedwe oyandikana nawo. Ponena za wolandirayo, pali zolinga zazikulu zitatu za mapangidwe a PCB: choyamba, ayenera kubwezeretsa molondola zizindikiro zazing'ono; chachiwiri, ayenera kuchotsa zizindikiro zosokoneza kunja kwa njira yomwe akufuna; ndipo chomaliza, monga chotumizira, ayenera kudya mphamvu Zochepa kwambiri.

Chizindikiro chosokoneza chachikulu cha kayesedwe ka ma radio frequency circuit

Wolandirayo ayenera kukhala wosamala kwambiri ndi zizindikiro zing'onozing'ono, ngakhale pamene pali zizindikiro zazikulu zosokoneza (zopinga). Izi zimachitika poyesa kulandira chizindikiro chofooka kapena chakutali, ndipo chowulutsira champhamvu chapafupi chikuwulutsa munjira yoyandikana nayo. Chizindikiro chosokoneza chikhoza kukhala 60 mpaka 70 dB chokulirapo kuposa chizindikiro chomwe chikuyembekezeka, ndipo chikhoza kuphimbidwa ndi kuchuluka kwakukulu panthawi yomwe wolandirayo akulowetsa, kapena wolandira akhoza kupanga phokoso lambiri panthawi yolowera kuti aletse kulandira ma sigino abwino. . Ngati wolandirayo akuthamangitsidwa kudera lopanda mzere ndi gwero losokoneza panthawi yolowera, mavuto awiriwa adzachitika. Kuti mupewe mavutowa, kutsogolo kwa wolandila kuyenera kukhala kozungulira kwambiri.
Chifukwa chake, "linearity" ndichinthu chofunikiranso pakupanga kwa PCB kwa wolandila. Popeza wolandirayo ndi kagawo kakang'ono, kusagwirizana kumayesedwa poyesa "intermodulation distortion". Izi zimaphatikizapo kugwiritsa ntchito mafunde awiri a sine kapena mafunde a cosine okhala ndi ma frequency ofanana ndi omwe amakhala pakati pa bandi kuti ayendetse siginecha yolowera, kenako kuyeza zomwe zatuluka. Nthawi zambiri, SPICE ndi pulogalamu yofananira yowononga nthawi komanso yotsika mtengo, chifukwa imayenera kuchita mawerengero ambiri a loop kuti ipeze ma frequency ofunikira kuti imvetsetse kupotoza.

Chizindikiro chaching'ono choyembekezeredwa mu RF circuit simulation

Wolandirayo ayenera kukhala watcheru kwambiri kuti azindikire zizindikiro zazing'ono zolowetsa. Nthawi zambiri, mphamvu yolowera ya wolandila imatha kukhala yaying'ono ngati 1 μV. Kutengeka kwa wolandila kumachepetsedwa ndi phokoso lopangidwa ndi gawo lake lolowera. Chifukwa chake, phokoso ndilofunikira kwambiri pamapangidwe a PCB a wolandila. Kuphatikiza apo, kuthekera kodziwiratu phokoso ndi zida zofananira ndikofunikira. Chithunzi 1 ndi wolandila superheterodyne. Chizindikiro cholandilidwa chimasefedwa poyamba, ndiyeno chizindikiro cholowera chimakulitsidwa ndi amplifier ya phokoso lotsika (LNA). Kenako gwiritsani ntchito oscillator yam'deralo (LO) kusakaniza ndi chizindikirochi kuti musinthe chizindikirochi kukhala ma frequency apakati (IF). Phokoso la gawo lakutsogolo limatengera LNA, chosakanizira ndi LO. Ngakhale kusanthula kwa phokoso la SPICE kungapeze phokoso la LNA, ndilopanda ntchito kwa osakaniza ndi LO, chifukwa phokoso lazitsulozi lidzakhudzidwa kwambiri ndi chizindikiro chachikulu cha LO.
Chizindikiro cholowera chaching'ono chimafuna kuti wolandirayo akhale ndi ntchito yayikulu yokulitsa, ndipo nthawi zambiri amafuna kupindula kwa 120 dB. Ndi kupindula kwakukulu kotere, chizindikiro chilichonse chophatikizidwa kuchokera kumapeto kwa zotuluka mpaka kumapeto kolowera kungayambitse mavuto. Chifukwa chofunikira chogwiritsira ntchito zomangamanga za superheterodyne receiver ndikuti zimatha kugawira phindu m'mafupipafupi angapo kuti achepetse mwayi wogwirizanitsa. Izi zimapanganso kuti mafupipafupi a LO oyambirira amasiyana ndi mafupipafupi a chizindikiro cholowetsamo, chomwe chingalepheretse zizindikiro zazikulu zosokoneza "kuipitsidwa" ku zizindikiro zazing'ono zolowetsa.
Pazifukwa zosiyanasiyana, muzinthu zina zoyankhulirana zopanda zingwe, kutembenuka kwachindunji kapena zomangamanga za homodyne zingalowe m'malo mwa superheterodyne zomangamanga. Pamapangidwe awa, chizindikiro cholowetsa cha RF chimasinthidwa mwachindunji kukhala pafupipafupi pagawo limodzi. Chifukwa chake, zopindulitsa zambiri zimakhala pafupipafupi, ndipo kuchuluka kwa LO ndi chizindikiro cholowera ndi chimodzimodzi. Pankhaniyi, chikoka cha kaphatikizidwe kakang'ono chiyenera kumveka, ndipo chitsanzo chatsatanetsatane cha "njira yosokera" chiyenera kukhazikitsidwa, monga: kugwirizanitsa kupyolera mu gawo lapansi, mapepala a phukusi, ndi mawaya ogwirizanitsa (Bondwire) pakati pa kugwirizana, ndi kugwirizana kupyolera mu chingwe chamagetsi.

Kusokoneza kwa tchanelo koyandikana mumayendedwe a wailesi pafupipafupi

Kupotoza kumagwiranso ntchito yofunika kwambiri pa transmitter. Zopanda mzere wopangidwa ndi transmitter mu gawo lotulutsa zimatha kufalitsa bandwidth ya siginecha yopatsirana mumayendedwe oyandikana. Chodabwitsa ichi chimatchedwa "spectral regrowth". Chizindikiro chisanafike pamagetsi amplifier ya transmitter (PA), bandwidth yake ndi yochepa; koma "kusokoneza intermodulation" mu PA kudzachititsa bandwidth kuwonjezeka kachiwiri. Ngati bandwidth ikuchulukirachulukira, wotumizirayo sangathe kukwaniritsa zofunikira zamphamvu zamakina ake oyandikana nawo. Mukatumiza ma siginecha osinthidwa ndi digito, kwenikweni, SPICE singagwiritsidwe ntchito kulosera za kukula kwa sipekitiramu. Chifukwa kutumiza kwa zizindikiro pafupifupi 1,000 (chizindikiro) kuyenera kutsatiridwa kuti tipeze mawonekedwe oyimira, ndipo mafunde onyamula ma frequency apamwamba ayenera kuphatikizidwa, zomwe zipangitsa kuti kusanthula kwakanthawi kwa SPICE kusakhale kothandiza.