1.What bụ Antenna?
Dị ka anyị niile maara, e nwere ụdị niile nke wngwaọrụ nzikọrịta ozi na-enweghị irena ndụ anyị, dị ka drone video downlink,wireless njikọ maka robot, dijitalụ ntupu usorona usoro mgbasa ozi redio ndị a na-eji ebili mmiri redio na-ebufe ozi dị ka vidiyo, olu na data.Antenna bụ ngwaọrụ eji enye ọkụ na ịnata ebili mmiri redio.
2.Antenna bandwit
Mgbe oge ọrụ nke antenna na-agbanwe, ogo mgbanwe nke paramita eletrik dị mkpa nke antenna dị n'ime oke ekwenyere.Ogologo oge a na-anabata n'oge a bụ obosara eriri eriri antenna, nke a na-akpọkarị bandwit.Antenna ọ bụla nwere ụfọdụ bandwit na-arụ ọrụ, ọ nweghịkwa mmetụta kwekọrọ na mpụga eriri ugboro a.
bandwit zuru oke: ABW=fmax - fmin
bandwidth ikwu: FBW=(fmax - fmin)/f0×100%
f0=1/2 (fmax + fmin) bụ ugboro etiti
Mgbe antenna na-arụ ọrụ na etiti etiti, oke ebili mmiri na-eguzo bụ nke kacha nta na arụmọrụ kachasị elu.
Ya mere, a na-egosipụtakarị usoro bandwidth ikwu dị ka: FBW=2(fmax-fmin)/(fmax+ fmin)
N'ihi na bandwidi antenna bụ nsonso ugboro na-arụ ọrụ ebe otu ma ọ bụ ụfọdụ paramita arụmọrụ eletriki nke antenna na-emezu ihe achọrọ, enwere ike iji ihe eletrik dị iche iche tụọ obosara bandwit.Dịka ọmụmaatụ, obosara bandwit nke kwekọrọ na obosara lobe 3dB (obosara lobe na-ezo aka na akụkụ dị n'etiti isi ihe abụọ ebe ike radieshon na-ebelata site na 3dB, ya bụ, njupụta ike na-ebelata site na ọkara, n'akụkụ abụọ nke ntụziaka radieshon kacha elu. nke isi lobe), na obosara bandwit ugboro ebe oke ebili mmiri guzoro na-ezute ụfọdụ ihe achọrọ.N'ime ha, nke a na-ejikarị bụ bandwit nke a na-atụle site na oke ebili mmiri na-eguzo.
3.The mmekọrịta n'etiti arụ ọrụ ugboro na antenna size
N'otu usoro ahụ, ọsọ mgbasa nke ebili mmiri electromagnetic doro anya (nha nha ọsọ nke ọkụ n'ime oghere, dekọrọ dị ka c≈3×108m/s).Dị ka c = λf si kwuo, enwere ike ịhụ na ogologo ebili mmiri na-agbanwe agbanwe na ugboro ole, na abụọ bụ nanị njikọ kwekọrọ.
Ogologo antenna ahụ dabara kpọmkwem na ogologo ikuku yana n'ụzọ na-agbanwe agbanwe na ugboro ole.Ya bụ, ka ọ na-adịwanye elu, ka ogologo wavele dị mkpụmkpụ, na mkpụmkpụ nke antenna nwere ike ime.N'ezie, ogologo nke antenna anaghị adịkarị ka otu wavelength, mana ọ na-abụkarị 1/4 wavelength ma ọ bụ 1/2 wavelength (n'ozuzu ogologo ogologo ogologo nke kwekọrọ na ugboro ọrụ etiti na-eji).N'ihi na mgbe ogologo nke onye nduzi bụ ọnụọgụ ọnụọgụ nke 1/4 wavelength, onye nduzi na-egosipụta njirimara resonance na ugboro nke ogologo wavelength ahụ.Mgbe ogologo nke onye nduzi bụ 1/4 wavelength, ọ nwere usoro resonance àgwà, na mgbe onye nduzi ogologo bụ 1/2 wavelength, ọ nwere yiri resonance àgwà.N'ọnọdụ resonance a, antenna na-enwusi ike na nnyefe na nnabata nnabata dị elu.Ọ bụ ezie na radieshon nke oscillator karịrị 1/2 nke wavelength, radieshon ga-aga n'ihu na-emewanyewanye, ma mgbochi-phase radieshon nke ngafe akụkụ ga-arụpụta a ịkagbu mmetụta, ya mere, n'ozuzu radieshon mmetụta na-emebi.Ya mere, antennas nkịtị na-eji nkeji ogologo oscillator nke 1/4 wavelength ma ọ bụ 1/2 wavelength.N'ime ha, antenna 1/4-wavelength na-ejikarị ụwa eme ihe dị ka enyo kama iji antenna ọkara-efegharị.
1/4 antenna wavelength nwere ike nweta oke ebili mmiri dị mma na mmetụta ojiji site na ịhazi nhazi ahụ, n'otu oge ahụ, ọ nwere ike chekwaa oghere nrụnye.Agbanyeghị, antennas nke ogologo a na-enwekarị uru dị ala ma enweghị ike igbo mkpa ụfọdụ ọnọdụ mgbasa ozi dị elu.N'okwu a, a na-ejikarị antenna 1/2-wavelength eme ihe.
Na mgbakwunye, egosipụtara na tiori na omume na usoro 5/8 wavelength (ogologo a dị nso na 1/2 wavelength mana ọ nwere radieshon siri ike karịa 1/2 wavelength) ma ọ bụ 5/8 wavelength loading shortening n'usoro (enwere E nwekwara ike ịmepụta ma ọ bụ họrọ eriri mkpuchi na ọkara nke ịdị anya site na elu nke antenna) iji nweta antenna uru dị ọnụ ahịa na nke dị elu.
Enwere ike ịhụ na mgbe anyị maara ugboro ole nke antenna na-arụ ọrụ, anyị nwere ike gbakọọ ogologo waveleng nke kwekọrọ, wee jikọta ya na usoro ntanetị nnyefe, ọnọdụ oghere ntinye na ihe ndị chọrọ nnyefe, anyị nwere ike mara ogologo oge kwesịrị ekwesị nke antenna achọrọ. .
Oge nzipu: Ọktoba 13-2023
