Lctu 31 Wi Antnnas n this lctu yu will lan: Gnatin f aiatin by al wi antnnas Sht ipl antnnas Half-wav ipl antnnas Th-half-wav ipl antnnas Small wi lp antnnas magntic ipl antnnas ECE 303 Fall 006 Fahan Rana Cnll Univsity Cnt F Wi Antnna Cnsi th fllwing wi antnna f via a tansmis lin: ( = ˆ δ ( δ ( y Z A A = k ( v ˆ = ˆ ( ( ˆ ˆ k ˆ. = ˆ k k cs ( ( f n is intst in aiatin fa-fils nly, thn assum:, << ECE 303 Fall 006 Fahan Rana Cnll Univsity k ˆ Fa-fil appimatin - als call th Faunh appimatin ( cs( φ + yˆ ( ( φ ˆ cs( Rcall that: ˆ = ˆ + 1
Cnt F Sht Dipl Wi Antnna - Sht ipl wi antnna f via a tansmis lin: Sht ipl << Z ( = ˆ δ ( δ ( y / -/ Mak an assumptin f th cunt istibutin n th antnna a tiangula istibutin ( A k k cs = ˆ ˆ k ( Wh: = ( ECE 303 Fall 006 Fahan Rana Cnll Univsity Sinc: < << k = ˆ A Htian-ipl-lik slutin = = Cnt F Sht Dipl Wi Antnna - Sht ipl wi antnna f via a tansmis lin: Sht ipl << / ( = ˆ δ ( δ ( y Z ( Th aiatin fm a sht ipl lks lik that fm a Htian ipl cpt E H k = ˆ η ( k k k = ˆ φ ( -/ * S(, t = R ( ( that is plac by ECE 303 Fall 006 Fahan Rana Cnll Univsity 1 { } η k = ˆ ( Pa = S(, t. ˆ ( φ 0 0 η = k 1
Cnt F Sht Dipl Wi Antnna - Sht ipl wi antnna f via a tansmis lin: Sht ipl << / ( = ˆ δ ( δ ( y Z ( Antnna Gain: F a sht ipl th gain is: S(, t. ˆ 3 G(, φ = = Pa Antnna Raiatin Pattn: G(, φ p, = = G ( φ ma ( ( -/ (, φ = 0 p 0 180 30 150 60 90 10 ECE 303 Fall 006 Fahan Rana Cnll Univsity Cnt F Half-Wav Dipl Wi Antnna - Half-wav ipl antnna f via a tansmis lin: Half-wav ipl = A Mak an assumptin f th cunt istibutin n th antnna a usial istibutin Z ( = ˆ δ ( δ ( y ˆ k k cs ( = 4 4 ˆ k cs 4 = ˆ k k / -/ k cs ( k cs cs( ( = cs( k ECE 303 Fall 006 Fahan Rana Cnll Univsity 3
Cnt F Half-Wav Dipl Wi Antnna - Half-wav ipl wi antnna f via a tansmis lin: Half-wav ipl = / Z ( = ˆ δ ( δ ( y ( = cs( k -/ = ˆ A k This implis: η ˆ = k k cs cs( ( cs cs( ( ˆ = φ k cs cs( ( ECE 303 Fall 006 Fahan Rana Cnll Univsity Cnt F Half-Wav Dipl Wi Antnna - Half-wav ipl wi antnna f via a tansmis lin: Half-wav ipl = (, φ = 0 p 0 Htian ipl 30 60 Z = ˆ δ ( δ ( y 10 Half-wav ipl This ttal pw aiat is: 150 180 Pa = S(, t.ˆ ( φ 0 0 cs cs( G(, φ 1.64 cs cs( η ( = ( φ 0 0 ( 1.η cs ( cs p(, φ = P R = a 73 Ω ( a ECE 303 Fall 006 Fahan Rana Cnll Univsity 90 4
Cnt F Th-Half-Wav Dipl Wi Antnna - Th-half-wav ipl = 3 / Mak an assumptin f th cunt istibutin n th antnna a usial istibutin Z ( = ˆ δ ( δ ( y ( = cs( k -/ A k cs ( = ˆ k ˆ k = ˆ k 3 4 cs 3 4 3 cs k k cs ( k cs( ( ECE 303 Fall 006 Fahan Rana Cnll Univsity Cnt F Th-Half-Wav Dipl Wi Antnna - 3 = / (, φ = 0 p 0 30 60 ( = cs( k 90 η ˆ = ˆ = φ -/ k k 3 cs 3 cs cs( ( cs( ( p (, φ 180 3 cs 150 10 cs( ( ECE 303 Fall 006 Fahan Rana Cnll Univsity 5
Hm Ma Dipl Antnnas A 1-5 GH hm-ma ipl antnna f Wilss LAN with a c-aial SMA RF f Buipl TM A 16 ft ipl f 1-50 MH ai ECE 303 Fall 006 Fahan Rana Cnll Univsity Raas f Upp Atmsph Rsach 49.9 MH inchnt scatt aa at th Pu Obsvaty Th aa has an aay f 18,43 half-wav ipls!! ECE 303 Fall 006 Fahan Rana Cnll Univsity 6
Antnnas f Mbil Cnsum Pucts A PCMCA ca antnna with tw css sht ipls shwn with th cv mv (f -5 GH A sht ipl antnna intgat with a lw nis amplifi n a PC ba f mbil civs (4-8 GH Raial stub tuns f impanc matching ECE 303 Fall 006 Fahan Rana Cnll Univsity Small Wi Lp Antnna A Magntic Dipl Raiat Cnsi a small lp f wi caying tim-vaying cunt: Small lp a << / ( A k = v y k ˆ ( ˆ. A φ = aφ 0 a s φ Nt that: ˆ φ = ˆ ( φ + yˆ cs( φ = ˆ a cs φ + yˆ a φ This givs: A A ( cs( φ + yˆ ( ( φ ˆ cs( ˆ = ˆ + a ( k = [ ˆ ( φ + yˆ cs( φ ] 0 k a ( [ cs( φ cs( φ + ( φ ( φ ] a φ ( k [ ˆ ( φ + yˆ cs( φ ] 0 [ 1+ k a ( [ cs( φ cs( φ + ( φ ( φ ]] φ ECE 303 Fall 006 Fahan Rana Cnll Univsity 7
Small Wi Lp Antnna - a << / a s φ y A Ttal pw aiat is: k ˆ φ ( k a η k a ˆ φ k ( ( k a k ( ˆ ( Fils a pptinal t th puct f th cunt an th aa f th lp η p(, φ = 0 0 4 P 30 a = k a 1 P Raiatin sistanc is: R a = = η ( k a 4 a 6 60 90 Raiatin pattn is: p ( φ (, φ G, = = G ma ( 180 150 10 ECE 303 Fall 006 Fahan Rana Cnll Univsity N-tun Small Wi Lp Antnna Cnsi a small lp f wi caying tim-vaying cunt: a << / N-tuns a η Ttal pw aiat is: P = ( k a y A k ˆ φ ( k N a η k N a ˆ φ k ( ( k N a k ( ˆ ( Fils a pptinal t th puct f th cunt an th aa f th lp 4 a N 1 P Ra = = η N k a 6 Raiatin sistanc is: 4 Raiatin pattn is: p ( φ (, φ G, = = G ma ( t is asi t btain lag aiatin sistancs with small lp antnnas (cntaining many tuns than with sht ipl antnnas f th sam si ECE 303 Fall 006 Fahan Rana Cnll Univsity 8
Elctic Dipl Raiats Vs Magntic Dipl Raiats << / q(t (t -q(t a (t a << / Enf (, t q( t = [ ˆ cs( + ˆ ( ] 3 ε Th lctic na-fil lks lik that f an lctic ipl Th magntic na-fil lks lik that f a magntic ipl H nf (, t ( t a = [ ˆ cs( + ˆ ( ] 3 k k = ˆ η ( k k ( = ˆ φ ( η k a k = ˆ φ ( k a k ( = ˆ ( ECE 303 Fall 006 Fahan Rana Cnll Univsity Wi Lp Antnnas in Cnsum Pucts A m lp antnna f 1-30 MH patin A 30 inch hm ma multipl tun lp antnna A 10 cm lp antnna with a f ECE 303 Fall 006 Fahan Rana Cnll Univsity 9
Wi Lp Antnnas in Mical Dvics - A flibl ban-ai chip f wilss EEG (Elctncphalgaphy masumnts at.4 GH with a lp antnna A flibl ban-ai chip f wilss EMG (Elctmygaphy masumnts at 433 MH with a lp antnna ECE 303 Fall 006 Fahan Rana Cnll Univsity Wi Lp Antnnas f Evyby - A ptabl lp antnna f 5-10 MH patin n smby s van A hm ma lp antnna in smby s backya Min is bigg says this guy! ECE 303 Fall 006 Fahan Rana Cnll Univsity 10