Passive Zvikamu muRF Circuits
Resistors, capacitors, Antennas. . . . Dzidza nezve passive zvikamu zvinoshandiswa muRF masisitimu.
RF masisitimu haana kunyanya kusiyana nemamwe marudzi emaseketi emagetsi. Iwo mimwe mitemo yefizikisi inoshanda, uye nekudaro izvo zvakakosha zvinoshandiswa muRF magadzirirwo anowanikwawo mumaseketi edhijitari uye yakaderera-frequency analog maseketi.
Nekudaro, dhizaini yeRF inosanganisira yakasarudzika seti yezvipingamupinyi uye zvinangwa, uye nekudaro hunhu uye mashandisirwo ezvikamu zvinoda kutariswa kwakanyanya kana isu tichishanda mumamiriro eRF. Zvakare, mamwe maseketi akasanganiswa anoita mashandiro akanyanya kunangana neRF masisitimu-haashandiswe mumaseketi akaderera-frequency uye anogona kusanzwisiswa zvakanaka nevaya vasina ruzivo rudiki neRF dhizaini maitiro.
Isu tinowanzo kurongedza zvikamu sezvinoshanda kana zvisingaite, uye nzira iyi inoshanda zvakaenzana munzvimbo yeRF. Nhau dzinokurukura zvinhu zvinongoitwa zvine hukama neRF maseketi, uye peji rinotevera rinovhara zvinoshanda.
Capacitors
Yakanaka capacitor yaizopa chaiyo yakafanana mashandiro eiyo 1 Hz chiratidzo uye 1 GHz chiratidzo. Asi zvikamu hazvina kumbove zvakanaka, uye zvisizvo zvecapacitor zvinogona kuve zvakakosha pamafafitera epamusoro.
"C" inoenderana neyakanaka capacitor inovigwa pakati pezvinhu zvakawanda zveparasitic. Tine kusagadzikana kusingagumi pakati pemahwendefa (RD), akateedzana kuramba (RS), akateedzana inductance (LS), uye parallel capacitance (CP) pakati pePCB pads nendege yepasi (tiri kufungidzira pamusoro-yegomo zvikamu; zvimwe pane izvi gare gare).
Kunyanya kukosha kusaita kana isu tichishanda neakakwira-frequency masiginecha ndeye inductance. Isu tinotarisira kuti iyo impedance ye capacitor ichaderera kusingaperi sezvo frequency inowedzera, asi kuvapo kweparasitic inductance kunokonzera iyo impedance kunyura pasi payo self-resonant frequency uye yobva yatanga kuwedzera:
Resistors, et al.
Kunyangwe zvinopikisa zvinogona kunetsa pamafafitera epamusoro, nekuti ane akateedzana inductance, parallel capacitance, uye yakajairika capacitance yakabatana nePCB pads.
Uye izvi zvinounza chinhu chakakosha: kana iwe uchishanda neakakwira ma frequency, parasitic circuit elements ari kwese kwese. Hazvina mhosva kuti chinhu chinopikisa chiri nyore kana chakanakira sei, chichiri kuda kuputirwa uye kutengeswa kuPCB, uye mhedzisiro yacho parasitics. Izvi zvinoshandawo kune chero chimwe chikamu: kana chakarongedzwa uye chakatengeswa kubhodhi, zvinhu zveparasitic zviripo.
Makristasi
Iwo musimboti weRF uri kushandisa masiginecha akakwira-frequency kuitira kuti ape ruzivo, asi tisati tanyengedza tinoda kugadzira. Semamwe marudzi emasekete, makristasi inzira yakakosha yekugadzira yakagadzikana frequency referensi.
Nekudaro, mudhijitari uye yakasanganiswa-chiratidzo dhizaini, kazhinji ndiyo nyaya yekuti masekete-akavakirwa sekristaro haadi iyo chaiyo iyo kristaro inogona kupa, uye nekudaro zviri nyore kuve vasina hanya nezve kusarudzwa kwekristaro. Iyo RF yedunhu, mukusiyana, inogona kunge iine yakasimba frequency zvinodiwa, uye izvi zvinoda kwete yekutanga frequency kurongeka chete asiwo frequency kugadzikana.
Iyo oscillation frequency yeyakajairwa crystal inonzwa nekusiyana kwetembiricha. Iyo inokonzeresa kusagadzikana kweiyo frequency inokonzeresa matambudziko eRF masisitimu, kunyanya masisitimu anozoratidzwa kune misiyano yakakura mukupisa kwemukati. Nokudaro, hurongwa hunogona kuda TCXO, kureva, tembiricha-inobhadhara crystal oscillator. Zvishandiso izvi zvinosanganisira kutenderera kunotsiva kusiyanisa kwekristaro frequency:
Antennas
Antenna chinhu chinongoitwa chinoshandiswa kushandura chiratidzo chemagetsi eRF kuita electromagnetic radiation (EMR), kana zvinopesana. Nezvimwe zvikamu uye maconductor tinoedza kuderedza mhedzisiro yeEMR, uye nema antennas tinoedza kukwidziridza chizvarwa kana kugamuchirwa kweEMR maererano nezvinodiwa zvekushandisa.
Antenna sainzi haisi nyore. Zvinhu zvakasiyana zvinopesvedzera maitiro ekusarudza kana kugadzira antenna iyo yakakwana kune imwe application. AAC ine zvinyorwa zviviri (tinya pano uye pano) izvo zvinopa yakanakisa sumo kune antenna pfungwa.
Mafambiro epamusoro anoperekedzwa neakasiyana dhizaini matambudziko, kunyangwe iyo antenna chikamu cheiyo sisitimu inogona kunyatsoita dambudziko sezvo frequency inowedzera, nekuti mafrequency epamusoro anobvumira kushandiswa kweantenna mapfupi. Mazuva ano zvakajairika kushandisa chero "chip antenna," iyo inotengeswa kuPCB seyakajairwa pamusoro-inokwira zvikamu, kana PCB antenna, iyo inogadzirwa nekubatanidza yakanyatso gadzirwa trace muPCB dhizaini.
Summary
Zvimwe zvikamu zvinongowanikwa muRF application, uye zvimwe zvinofanirwa kusarudzwa nekuitwa zvine hungwaru nekuda kwemaitiro avo asina kunaka epamusoro-frequency.
Passive components zvinoratidza nonideal frequency response semhedzisiro yeparasitic inductance uye capacitance.
RF zvikumbiro zvinogona kuda makristasi akanyatsojeka uye/kana akagadzikana kupfuura makristasi anowanzo shandiswa mumaseketi edhijitari.
Antennas zvinhu zvakakosha zvinofanirwa kusarudzwa zvinoenderana nehunhu uye zvinodiwa zveRF system.
Si Chuan Keenlion Microwave sarudzo yakakura mune narrowband uye Broadband masisitimu, inovhara ma frequency kubva 0.5 kusvika 50 GHz. Iwo akagadzirirwa kubata kubva pagumi kusvika pamakumi matatu ekuisa simba mu50-ohm transmission system. Microstrip kana stripline madhizaini anoshandiswa, uye akakwenenzverwa kuita zvakanaka.
Nguva yekutumira: Nov-03-2022
