Kana iyo analogi yedunhu (RF) uye yedhijitari yedunhu (microcontroller) ichishanda zvakanaka mumwe nemumwe, asi kana wangoisa maviri pabhodhi redunhu rimwe chete uye kushandisa simba rakafanana kuti rishande pamwe chete, hurongwa hwese hunogona kunge husina kugadzikana. Izvi zvinonyanya kuitika nekuti chiratidzo chedhijitari chinowanzo kutenderera pakati pepasi uye yakanaka magetsi ekupa (saizi 3 V), uye nguva yacho ipfupi, kazhinji ns level. Nekuda kweamplitude yakakura uye nguva diki yekuchinja, aya masaini edhijitari ane huwandu hukuru hwepamusoro-frequency zvikamu zvakasununguka kubva kune inochinja frequency. Muchikamu cheanalogi, chiratidzo kubva kune antenna tuning loop kuenda kune inogashira chikamu chewaya isina waya kazhinji isingasviki 1μV.
Kusagadzika kwakaringana kwemitsara inonzwisisika uye mitsara ine ruzha idambudziko rinogara richiitika. Sezvambotaurwa pamusoro apa, masaini edhijitari ane kusvetuka kwepamusoro uye ane nhamba huru ye-high-frequency harmonics. Kana iyo yedhijitari siginecha wiring paPCB iri padhuze neanonzwisisika analogi masaini, yakakwira-frequency harmonics inogona kubatanidzwa yapfuura. Manode anonzwa emidziyo yeRF anowanzo tenderera sefa yechikamu-yakakiyiwa loop (PLL), yekunze voltage inodzorwa oscillator (VCO) inductor, iyo crystal referensi chiratidzo uye antenna terminal, uye zvikamu izvi zvedunhu zvinofanirwa kurapwa. nokungwarira.
Sezvo iyo yekupinza / yekubuda siginecha ine kutenderera kweV akati wandei, maseketi edhijitari anowanzo gamuchirwa kune ruzha rwemagetsi emagetsi (pasi pe50 mV). Maseketi eAnalog anonzwa ruzha rwemagetsi ekupa ruzha, kunyanya kune burr voltages uye mamwe marefu frequency harmonics. Naizvozvo, tambo yemagetsi inofamba paPCB board ine RF (kana mamwe analogi) maseketi anofanirwa kungwarira kupfuura waya pane yakajairwa dhijitari redunhu bhodhi, uye otomatiki nzira inofanirwa kudzivirirwa. Izvo zvinofanirwa kucherechedzwa kuti microcontroller (kana imwe dhijitari yedunhu) inongoerekana yayamwa mune yakawanda yazvino kwenguva pfupi panguva yega yega yemukati wachi kutenderera, nekuda kweiyo CMOS dhizaini dhizaini yemazuva ano microcontrollers.
Iyo RF yedunhu bhodhi inofanirwa kugara iine yepasi mutsara layer yakabatana kune yakaipa electrode yemagetsi emagetsi, ayo anogona kuburitsa zvimwe zvinoshamisa kana zvikasabatwa nemazvo. Izvi zvinogona kuomera mugadziri wedhijitari wedhijitari kuti anzwisise, nekuti mazhinji edhijitari maseketi anoshanda nemazvo kunyangwe pasina dhizaini. MuRF bhendi, kunyangwe waya pfupi inoita senge inductor. Zvikaverengerwa, iyo inductance pamm kureba ingangoita 1 nH, uye inductive reactance ye10 mm PCB mutsetse pa434 MHz ingangoita 27 Ω. Kana mutsara wepasi usingashandisi, mitsetse yakawanda yepasi ichave yakareba uye dunhu harizovimbisi maitiro ekugadzira.
Izvi zvinowanzo furatirwa mumaseketi ane redhiyo frequency nezvimwe zvikamu. Pamusoro peiyo RF chikamu, kazhinji pane mamwe analog maseketi pabhodhi. Semuenzaniso, akawanda ma microcontrollers ane analog-to-digital converters (ADCs) akavakirwa-mukati-mune analog-to-digital converters (ADCs) kuyera mapikisi eanalog pamwe nebhatiri voltage kana mamwe maparameter. Kana iyo RF transmitter's antenna iri padyo (kana pa) iyi PCB, iyo yakaburitswa yakakwirira-frequency siginecha inogona kusvika kune analog yekupinda yeADC. Usakanganwa kuti chero mutsara wedunhu unogona kutumira kana kugamuchira masaini eRF senge antenna. Kana iyo ADC yekuisa isina kunyatsogadziriswa, iyo RF siginecha inogona kuzvifadza muESD diode yekuisa kuADC, zvichikonzera ADC kutsauka.
Zvose zvinobatanidza kune pasi pasi zvinofanira kunge zvakapfupika sezvinobvira, uye pasi kuburikidza-gomba rinofanira kuiswa (kana kuti pedyo zvikuru) padhi yechikamu. Usambobvumira masaini maviri epasi kuti agoverane ivhu kuburikidza-gomba, izvo zvinogona kukonzera crosstalk pakati pemapadhi maviri nekuda kwekupfuura-gomba yekubatanidza impedance. Iyo decoupling capacitor inofanira kuiswa pedyo nepini sezvinobvira, uye capacitor decoupling inofanira kushandiswa papini imwe neimwe inoda kubatanidzwa. Uchishandisa emhando yepamusoro ceramic capacitors, iyo dielectric mhando ndeye "NPO", "X7R" inoshandawo nemazvo mumazhinji maapplication. Iyo yakakosha kukosha kweiyo yakasarudzwa capacitance inofanira kunge yakaita kuti nhepfenyuro yayo resonance yakaenzana neyechiratidzo frequency.
Semuenzaniso, pa434 MHz, iyo SMD-yakaiswa 100 pF capacitor ichashanda zvakanaka, panguva iyi frequency, iyo capacitive reactance ye capacitor inenge 4 Ω, uye inductive reactance yegomba iri mumhando imwechete. Iyo capacitor uye gomba munhevedzano inoumba notch sefa yeiyo frequency yechiratidzo, ichiibvumira kuti inyatso kubatanidzwa. Pa868 MHz, 33 p F capacitors isarudzo yakanaka. Pamusoro peiyo RF yakadhirowewa diki kukosha capacitor, yakakura kukosha capacitor inofanirawo kuiswa patambo yemagetsi kuti ibvise yakaderera frequency, inogona kusarudza 2.2 μF ceramic kana 10μF tantalum capacitor.
Nyeredzi wiring inyanzvi inozivikanwa mune analog wedunhu dhizaini. Nyeredzi wiring - Imwe neimwe module iri pabhodhi ine yayo tambo yemagetsi kubva kune yakajairwa magetsi emagetsi poindi. Muchiitiko ichi, nyeredzi wiring zvinoreva kuti dhijitari neRF zvikamu zvedunhu zvinofanirwa kunge zvine tambo dzemagetsi, uye idzi tambo dzemagetsi dzinofanirwa kubatanidzwa zvakasiyana pedyo neIC. Uku kuparadzaniswa nenhamba
Nzira inoshanda yechikamu uye magetsi ekupa ruzha kubva kuRF chikamu. Kana ma modules ane ruzha rwakanyanya akaiswa pabhodhi rimwe chete, iyo inductor (magnetic bead) kana diki kuramba (10 Ω) inogona kubatanidzwa mumutsara pakati petambo yemagetsi uye module, uye tantalum capacitor inosvika gumi μF. inofanirwa kushandiswa semagetsi ekupa decoupling yemamodule aya. Ma modules akadaro RS 232 madhiraivha kana kushandura magetsi ekugadzirisa magetsi.
Kuti uderedze kupindira kubva kune ruzha module uye yakapoteredza analog chikamu, marongerwo ega ega module module pabhodhi yakakosha. Sensitive modules (RF zvikamu uye antennas) anofanirwa kugara achichengetwa kure nemamodule ane ruzha (microcontrollers uye RS 232 madhiraivha) kudzivirira kukanganiswa. Sezvambotaurwa pamusoro, masaini eRF anogona kukonzera kukanganisa kune mamwe anonzwisa analog sedunhu modules seADCs kana atumirwa. Matambudziko mazhinji anoitika mumabhendi epasi anoshanda (akadai se27 MHz) pamwe neakakwira simba rekubuda mazinga. Iyo yakanaka dhizaini dhizaini yekumisikidza mapoinzi ane hunyoro neRF decoupling capacitor (100p F) yakabatana pasi.
Kana uri kushandisa tambo kubatanidza RF board kune yekunze dhijitari wedunhu, shandisa dzakamonyoroka-matambo tambo. Imwe neimwe tambo yechiratidzo inofanirwa kupetwa netambo yeGND (DIN/ GND, DOUT/ GND, CS/ GND, PWR _ UP/ GND). Rangarira kubatanidza iyo RF yedunhu bhodhi uye dhijitari application yedunhu bhodhi neGND tambo yeyakamonyoroka-pairi tambo, uye kureba kwetambo kunofanirwa kuve kupfupi sezvinobvira. Iyo wiring inopa simba RF bhodhi inofanirwawo kumonyaniswa-neGND (VDD/ GND).
