ANT0104 Ultra Wideband Omnidirectional Ententa

Don aunawa mai amfani na ma'aunin D na hanyar sadarwa ta eriya, mun ayyana shi daga girman kewayon hasken eriya.

Kai tsaye D shine rabon matsakaicin yawan ƙarfin da aka haskaka P(θ,φ) zuwa matsakaicin ƙimar P(θ,φ)av akan wani yanki a yankin nesa, kuma rabo ne mara girma wanda ya fi ko yayi daidai da 1. Tsarin lissafi kamar haka:

Bugu da ƙari, ana iya ƙididdige jagorancin D ta hanyar dabarar da ke ƙasa:

D = 4 PI / Ω _A

A aikace, ana amfani da lissafin logarithmic na D sau da yawa don wakiltar ribar alkiblar eriya:

D = log 10⁡ d

Ana iya fassara D kai tsaye da ke sama a matsayin rabon kewayon ƙwallo (4π rad²) kewayon ω _A. Misali, idan eriya tana haskakawa ne kawai zuwa sararin sama mai faɗi kuma kewayon ƙwallonta shine ω _A=2π rad², to kai tsaye ita ce:

Idan aka ɗauki logarithm na ɓangarorin biyu na lissafin da ke sama, za a iya samun ribar alkiblar eriya dangane da isotropy. Ya kamata a lura cewa wannan ribar za ta iya nuna hasken tsarin alkiblar eriya ne kawai, a cikin naúrar dBi, tunda ba a ɗauki ingancin watsawa a matsayin mafi kyawun riba ba. Sakamakon lissafi sune kamar haka:

Aji 3.01: : dBi d = log 10⁡ abu 2

Raka'o'in samun antenna sune dBi da dBd, inda:

DBi: shine ribar da aka samu ta hanyar hasken eriya dangane da tushen ma'aunin, saboda tushen ma'aunin yana da ω _A=4π kuma ribar shugabanci shine 0dB;

DBd: shine ribar hasken eriya idan aka kwatanta da eriyar dipole ta rabin-wave;

Tsarin juyawa tsakanin dBi da dBd shine:

Aji na 2.15: : dBi 0 kayan DBD