The Oven{{0}Controlled Crystal Oscillator (OCXO) ke mofuta oa kristale oscillator e khonang ho fumana botsitso bo phahameng{{1}ka nako e telele{2}}ka theknoloji ea ho laola mocheso. Molao-motheo oa eona oa mantlha o kenyelletsa ho aha kristale ka har'a kamore ea onto e laoloang ka mocheso, moo lipotoloho tsa ho futhumatsa le mocheso li bolokang mocheso o sa feleng oa kristale. Sena se fokotsa haholo phello ea phapang ea mocheso ho maqhubu.
Melemo ea mantlha ea li-OCXO tse Fatšeng-Baamoheli ba Satellite ba Thehiloeng:
1. High Frequency Stability:
Boemo bo Hlokehang: Matshwao a satellite (mohlala, puisano, disathelaete tsa ho tsamaya) hangata a sebedisa{2}}dibapalami tsa maqhubu a hodimo (mohlala, L-lehlopha, C-lehlopha). Baamoheli ba hloka{8}}phetoho le ho theoleloa ho hokahaneng ho ntša data, ho hloka botsitso bo phahameng haholo ho tsoa ho oscillator ea lehae.
Molemo oa OCXO: Li-OCXO li boloka mocheso oa kristale ka har'a ± 0.1℃ka phaposi ea ontong. Botsitso bo tloaelehileng bo tloha ho ±1×10⁻⁹ ho isa ±1×10⁻¹¹ (ho hoholeha ha letsatsi le letsatsi), ho feta hōle li-crystal oscillator tse tloaelehileng (XOs) kapa mocheso{6}}li-compensated crystal oscillator (TCXOs). Botsitso bona bo fokotsa haholo Sekhahla sa Phoso ea Bit (BER) nakong ea tlhahiso ea matšoao.
2. Lerata le Tlase:
Boemo ba Kopo: Lipontšo tsa satellite hangata li sebelisa mekhoa e phahameng ea ho feto-fetoha ha data (mohlala, QPSK, 16APSK). Lerata le feteletseng la mohato le etsa hore setšoantšo sa linaleli se be lerootho, se eketsa BER.
Karolo ea OCXO: Li-OCXO hangata li bonts'a lerata la mohato ka tlase ho -150 dBc/Hz ho 1 kHz offset. Sena se tiisa bohloeki ba ponahalo ea lets'oao la oscillator ea lehae, ho ntlafatsa ho nepahala ha demodulation.
3. Ho hanana le ho Fetoha ha Mocheso:
Phephetso ea Tikoloho: Ba amohelang fatše ba ka ba boemong bo fapaneng ba mocheso o feteletseng (mohlala, -40 degrees ho isa ho +70℃), e leng se bakang ho hoholeha ha li-oscillator tse tloaelehileng ka lebaka la phello ea mocheso.
Mokhoa oa Oven: Sefuthumatsi se ka hare se boloka kristale ka mafolofolo mochesong o sa fetoheng (mohlala, +75℃). Esita le nakong ea liphetoho tse matla tsa mocheso ka ntle, frequency drift e hatelloa ho ea likarolong ho ea ka tekanyo ea bilione (ppb), e netefatsang{4}}boemo bohle ba boemo ba leholimo.
4. Matšeliso a Doppler Shift:
Satellite Dynamics: Lisathalaete tsa Low Earth Orbit (LEO) (mohlala, Starlink, GPS) li hlahisa liphetoho tsa maqhubu a Doppler (hangata ±10 kHz ho isa ±100 kHz) ka lebaka la-motsamao o phahameng. Baamoheli ba tlameha ho latela liphetoho tsena khafetsa ka nako-ea sebele.
Ts'ehetso ea OCXO: Oache ea litšupiso e tsitsitseng haholo ho tsoa ho OCXO e fana ka motheo bakeng sa Phase-Locked Loop (PLL), ho netefatsa hore oscillator ea lehae e khona ho lekola liforomo tsa maqhubu ka potlako le ka nepo, ho thibela tahlehelo ea matšoao.
5. Puseletso ea Nako e Telele- ea Botsofali:
Nako e Telele-Botsitso ba Nako: Li-OCXO hangata li na le sekhahla sa ho tsofala sa <±0.1 ppm, ha se bapisoa le ±2 ppm/selemo kapa ho feta bakeng sa li-oscillator tse tloaelehileng. Sena se bohlokoa haholo bakeng sa liteishene tsa sathelaete tsa fatše tse hlokang-ts'ebetso e tsoelang pele ea nako e telele (mohlala,{7}}khokahanyo e tebileng ea sepakapaka), ho fokotsa ho lekanya le ho lokisa khafetsa.
6. Mekhahlelo e Tloaelehileng ea Maqhubu:
Li-OCXO tse sebelisoang hangata ho li-receiver tsa sathelaete li sebetsa haholo-holo ka har'a mekhahlelo e latelang ea maqhubu:
10 MHz: E sebetsa e le maqhubu a litšupiso a bohlokoa, a sebelisoang haholo ho hlahisa-maqhubu a maqhubu a holimo a oscillator ea sebakeng seo (ka ho atisa PLL) kapa ka ho toba e le oache e sebetsang ea baseband.
100 MHz: E loketse-ho sebetsa ka lebelo le holimo la matshwao a dijithale (mohlala, ADC/DAC sampling clock) kapa ho khanna RF front{4}}ka ho toba.
Maqhubu a mang a Khethehileng: joalo ka 10.230 MHz, 20 MHz, 25 MHz, 50 MHz, joalo-joalo, e hlophisitsoeng ho latela litlhoko tsa sistimi.
Motheo oa Khetho ea Maqhubu:
(1) Satellite Signal Band & Down{1}}Litlhoko tsa Phetoho:
Li-satellite receiver li theohile-fetola{1}}maqhubu a phahameng-ka mohlala, L, C, Ku-band) hore e be Maqhubu a Hare (IF). Li-OCXO li sebelisoa hangata maemong ana:
Mohloli oa Litšupiso oa Local Oscillator (LO):
Mohlala: Bakeng sa ho amohela mats'oao a L-(1{3}}2 GHz), 10 MHz OCXO e ka sebetsa joalo ka tšupiso ea PLL, e atisang ho hlahisa LO (mohlala, 1 GHz).
Mohlala: C-baamoheli ba sehlopha (4-8 GHz) ba ka sebelisa 100 MHz OCXO, PLL e kopanya lets'oao le phahameng la LO.
Ts'ebetso e tobileng ea IF:
Mohlala: Haeba IF e le 70 MHz kapa 140 MHz, OCXO e ka fana ka lebelo la oache ka kotloloho ho khanna ADCs/DAC kapa li-demodulator chips.
(2) Mehaho ea Sisteme le Litlhaloso tse Tloaelehileng:
Baamoheli ba GNSS (GPS/BeiDou):
Mohlala: Li-chips tsa Baseband hangata li hloka maqhubu a litšupiso joalo ka 16.368 MHz (GPS L1) kapa 10.23 MHz (oache ea mantlha ea GPS), ka li-PLL tsa kahare tse hlahisang maqhubu a hlokahalang.
Mohlala:{0}}Baamoheli ba nepahetseng haholo (mohlala, RTK) ba ka sebelisa 10 MHz OCXO ka kotloloho e le litšupiso tsa kantle ho matlafatsa botsitso ba oache.
Satellite TV (DVB-S2/S2X):
Mohlala: Leqhubu la Local Oscillator (LO) ho LNB (Low-Noise Block downconverter) hangata ke 9.75 GHz kapa 10.6 GHz (Ku-band), empa oache ea eona hangata e tsoa ho 10 MHz OCXO e khannang PLL.
Liteishene tsa Lefatše tsa Puisano ea Satellite (VSAT):
Mohlala: E ipapisitse le maemo a khokahano ea ITU-T G.813, oache e kholo hangata e sebelisa 10 MHz kapa 20 MHz (E1 interface clock) OCXO.
(3) Litlhokahalo tsa Ts'ebetso ea Lets'oao la Dijithale:
ADC/DAC Sampling Clock:
Mohlala: Haeba moamoheli a sebelisa 100 MSPS (Mega Samples Per Second) ADC, 100 MHz OCXO e ka hlokoa ho fana ka oache ea sampole ka kotloloho, ho fokotsa jitter.
FPGA/ASIC Baseband Processing:
Mohlala: Khokahano ea data e ts'oanang ea li-chips tsa baseband e ka hloka lioache tse lumellanang ho 25 MHz, 50 MHz, kapa 125 MHz.
Mehlala e Tloaelehileng ea Tšebeliso:
(1) GPS Receiver:
Maqhubu a OCXO: 10 MHz (Reference Reference)
Mosebetsi: E hlahisa 1575.42 MHz (L1 band) lets'oao la oscillator ea lehae ka PLL mme e fana ka nako e nepahetseng ho baseband.
(2) LEO Satellite Communication Terminal (mohlala, Starlink):
Maqhubu a OCXO: 100 MHz
Mosebetsi: E khannela-li-ADC tsa lebelo (mohlala, 1 GSPS) le-li-PLL tse ngata, tse nolofalletsang ho fumanwa le ho latedisa matshwao a Ku-band (12-18 GHz).
Hangjing e fana ka thomello e potlakileng (libeke tse 1 ~ 2) tsa lihlahisoa tse tloaelehileng ka har'a liphutheloana tse fapaneng, hammoho le li-OCXO tse etselitsoeng ho fihlela litlhoko tse ikhethang tsa bareki.
Ikopanye le Barekisi ba Hangjing kapa Baenjiniere ba Tekheniki bakeng sa Lintlha!
Kakaretso:
Ka mokhoa o ikhethang oa botsitso le lerata le tlase, Oven{{0}Li-Crystal Oscillator tse Laoloang li sebetsa e le mohloli oa mantlha oa li-satellite{1}tse li amohelang. Li loketse ka ho khetheha bakeng sa maemo a phahameng-a matla, a tlase a Signal-ho-Noise Ratio (SNR). Leha ho na le mefokolo ea tšebeliso ea matla le boholo, li-OCXO e ntse e le khetho ea bohlokoa maemong a bohlokoa joalo ka ho sesa, puisano le ho lemoha hole.