Half Wave Dipole - Lecture Notes | Antenna Design | EE 522, Study notes of Electrical and Electronics Engineering

Download Half Wave Dipole - Lecture Notes | Antenna Design | EE 522 and more Study notes Electrical and Electronics Engineering in PDF only on Docsity! EE522 NOTES (3) e Half-wave Dipole: Formation: SL ee ~, . * —t~_ x fr 2. “SoREE) \/ \ MO i ‘\ - tp Tieeers racrScew pec, | Lurifh open eo —_— | L@) = Sin BCA-1a1) Length: / 2L λ= Current: ( ') sin[ ( | ' |)] 4m I z I z λβ= − Location: z=0 Orientation: ẑ z L Far-field Potential: / 2 ˆ ' / 2 ˆ( ) sin ( | ' |) ' 4 4 j r L j r r mL e A r e zI z dz r β βµ λβ π − ⋅ −  = −  ∫ ˆ ˆ ˆ ˆsin cos sin sin cos ˆ ˆ ˆ ˆ' ' ' ' ' (Current on z-axis only). ˆ ' cos r x y z r xx yy zz zz r r θ φ θ φ θ θ = + + = + + = ⋅ = Radiation field: 2 cos[( / 2)cos ]ˆ( ) 4 sin j r mj I eE r r βωµ π θθ πβ θ − = Radiation pattern: cos[( / 2)cos ] ( ) sin Fθ π θθ θ = Input impedance (infinitely thin wire): 73 42.5 ( )AZ j= + Ω : L=Half wavelength 70 0 ( )AZ j= + Ω : Resonance (slightly less than / 2λ ) le) = Jn Saf’ [z-!2]) L Dipole of Length L i { Pastera cheeractercaen Reamwidth 4 Dire auity tT L ineréards Ti SUL 4 wher L» , Tue main lobes CveT Geng) ( Pain Lobe splits fer Large L) Phy ical Waker Drecation Te ! WL ip Caverentes on dip e a are ty phase PLAWE mage vertical avert: Fo Z[e et zoh Lmage Cunrent , ee i wiceen _ Current : - stiles at teh Lage Gorrete ; Fi=-€1.4 oe 2e=-h q GGneRaL case; SouReE at eh; Lena ge At deh, © 7.2) a(5-7-4