In this paper, we are dealing with a L-band power combiner method using the Wilkinson bridge.. This is a modem power combination technique in the microwave technology.. The design and si
Trang 1VNU Journal o f Science, Mathematics - Physics 25 (2009) 185-189
Research, design and fabrication o f a high-power combiner
using W ilkinson bridge o f L-band
Dang Thi Thanh Thuy' *, Vu Tuan Anh^, Vu Duy Thong^,
Bach Gia Duong^
Faculty o f Physics, College o f Science, Vietnam National University Hanoi
’Research Center Electronics and Telecommunication, College o f Technology, VNU
D epartm ent o f Science a nd Technology, Ministry o f Defense, Hanoi, Vietnam
Received 24 June 2009
A bstract In this paper, we are dealing with a L-band power combiner method using the Wilkinson bridge This is a modem power combination technique in the microwave technology The design and simuỉink o f the basic power moduls and Wilkinson bridge were performed using the ADS soflware We have researched, designed and fabricated the power combination from the basic 200W moduls The experimental results showed that power combination method using the Wilkinson bridge may be applicable in the L-band transmission
Keyword: Microware, Wilkinson, power combination
Ỉ Introductiun
The a ssem b le o f the L-band h igh-pow er am plifier is usually difficult, therefore the search for the pow er com b in atio n m e th o d s is important T he po w er com bination m ethod using the W ilkinson bridge IS one o f m e th o d s that have been taken into account W e have studied and aplied this method ibr c o m b in in g p o w e r from the basic modules W ilkinson p o w e r divider w as proposed by E J Wilkinson [ 1 ], as a m e th o d o f distributing po w er to attain equiphase and equiam plitude condition
2 T heories
The W ilk in so n p o w e r d ivider can use as com biner or divider It is a simple po w er divider cannot sim ultaneously h ave all the properties o f lossless, reciprocal, an d m atched Hence, the W ilkinson pow er divider w as developed Here, an isolation resistor is placed b etw ee n the output ports to help achieve the properties D issipation o f energy occurs only in isolation resistor w hen signal enters the network from an y o u tp u t port H ow ever, it should not affect W ilkinson netw ork efficiency Besides, this isolation resistor p ro v id es perfect isolation to protect output ports at the operating frequency
Correcsponding author E-mail: dangthuyhn@gmail.com
185
Trang 2186 D T Thuy ei cil / VNU Journal o f Science Mathematics - Physics 25 (2009) ỈS5-Ỉ89
Generallv, W ilkinson p o w e r d iv id e r can have anv n u m b e r o f output ports A basic three por
W ilkinson pow er d iv id er o f p o rt characteristic im pedance Zo is schem atically show n in F igure I
Fig 1 Schematic diagram of aWilkinson power divider [1]
This IS a such n e tw o rk that th e lossless and resistive T -junction p o w e r dividers have no isolation
b e tw e e n th e o u tp u ts o f p o rt 2 an d p o rt 3, and the lo s s le s s d iv id e r IS n o t m a tc h e d at all p o rts, and the
resistive pow er divider is lossy T h e W ilkinson pow er divider has all ports m a tc h e d and has isolation betw een output ports, b u t is lossy [1] T h e W ilkinson po w er divider is a 3-port device w ith a scattering matrix of:
- J
- j l ề
0 0
( 1 )
Note this device IS m a tc h e d at p o rt 1 ( S n = 0), and we find that m agnitude o f colum n 1 is:
o i l ’ S 2 1 ' 0 3 1 “ 1
Ih u s , ju s l like the lossless d iv id e r the incident pow er on port 1 IS evenly and cííicicn ily divided betw een the outputs o f po rt 2 an d port 3 But now look closer at the scattering matrix W c also note that the ports 2 and 3 o f this d e v ic e are matched It looks a lot like a lossless 3dB divider, only with an additional resistor b e tw e e n p o rts 2 an d 3
(2)
3 Design W ilkin son p o w e r d iv id e r
W e simulate the W ilk in s o n b rig d c by A DS solfware (figure 2a), the frequency o f transmission signal is 1030 M H z, w e retrieve the S-matrix param eter m agnitudes depicted in F igure 2b, 2c The
1030 M H z frequency w as s tu d ie d b ecause this frequency will application in our the next rescach for design and fabrication o f a tra n s m itte r system for the phase identification code
Trang 3D T Thuy el al / \'NIJ Journal o f Science, Maihemaiics - Physics 25 (2009) Ỉ 85-189 87
COfN*-é ể i
•CT5T5
Ũ
- 1 0 -
-20-
• 30-
-40 50 •
- í
-n r — n l e f T
m i
s TifrrC
Su0st='MSucr Sut»t=*MSubr z = 5 0 0 h m W=1 53303 rm { Q w = 2 9 6 3 2 3 0 rrm
WTo:_AO.S L=40 3207rT ĩn{ạ
1 T n -i
L=10frm{-t) 1
0—
Ĩwm1
2=50 Ohrr
TL1
Subsr^W SuCl*
V^^2 9632XrTm
L=lQfmi{-t}
SuDsp'fcejcr WM53rm
W 3 = 2 9 6 3 ittti
R1 ftiiOOOfvn
'A \
Ĩ1 1 3
Subst^-MSdbt'
V^lS33C3fTTTi{1}
L 41 5207fiTn(ị
‘.I ?i T112 Sutet^^-MSubl'
W=r2 9 6 3 2 3 0 m
L=10rrm{-t}
I
Terr T«rrM
^*ấI»=3
z=500m
(a)Tlie Wilkinson by ADS solfware
.m2
■freq=1 030GHz
,dB(S(2,2))=-39 305
m1
;freq=1 030GHz ỜB(S(2.1))=-3 011
ml
t y
0 2 0 4 0 6 1 0 1 2 1 4 1 6 1 8
( b ) S
freq, GHz
parameter mamiitude
freq GHz
(c) s parameter magnitude
FMg 2 T h e s e m u l i n k results.
Base on W ilkinson brigde niclhods, wc propose a com bination m e th o d s from the m edium pow er mociul and the small po w er m odul (Figure 3)
2()()W
Fig 3 The power combining use Wilkinson brigde
4 E xp erim en ts result
We have designed and fabricated the 200W am plifier m o d u le s fro m th e sm aller ones T he basic modules w ere designed by using the microtrip technology [4], w h ic h are small and portable (figure 4a) After sim ulink m odelling, the W ilkinson bridge w as designed u s in g th e m odern accurate circuit imprint technology [2,3](figure 4b)
Trang 488 D T Thỉiy et a! / Ỉ'NU Journal o f Science, Mathematics - PhysiCs 25 (2009} ỉiS5~ỈS9
Fig 4 T h e 2 0 0 W p o w e r a m p li fie r (a) T h e W ilk in s o n bridize (b).
From the basic am plifier m o d u ls and Wilkinson bridge divider w e have fabricated the h iuh-pow cr com bination circuit as illustrated in figures
hig 5 i he integration 0Í the Ircquency combinanon circuit
The am plifier m odules w e re carefully chccked to assure the com patibility so that the risk o f malfuction after the integration is minimal Obscr\Mim the w orking o f the 20 0 W a m p lin c r by
the network analyzer (Rolde &L S c h w a rz ESPi, 9 K llz -3 G llz , lest receiver), we r c \c a le d tliat the ban d
width was quite w ide and the a m p lify in g coefficient has achieved the high v alue w ithin tlic trequencN ranee 9 0 5 M H z -1 0 6 0 M lỈ7 (F'ig 6a)[4] The signal at 1030 M H z w as inputcd iiilo tlie am plifying module and observed on the sp c c tru m analvzcr (A dvanlcsl R3765CG (300 K lIz-3 8 G H z)), the result showed that at 1030 M l l z the a n ip lify in g cocfUcicnt read ied high value, tlie input am plitude w as set
a t-lO d B and the output one w a s a b o v e 16dB The adjustm ent o f current regim e m av increase the
am plifying coefficient even m ore We have also investigated tlie S il factor o f the pow er divider Wilkinson on network a n a ly /x r, the result was relatively sim ilar to that o f the sim ulink model Aftcrthal we have m easured the characteristics o f the pow er c o m b in er using the W inkinson bridge The input am plitude from the g e n e ra to r was set at -lOdB and w as directed to the am plifier module before the divider This pow er a m p lifie r was com posed from the three m odules having the p ow er IW, 45W and 200W T he output a m p litu d e reached 29dB The signal w as then transm itted to the divider, the two outputs also reached 2 6 d B and were synchronized The outputs w ere inputed to the 200W amplifier modules T hese m o d u le s w ere set to work in the A B regim e with am plifying
Trang 5D T Thuy et al / \ ’NU Journal o f Science, Mathematics - Physics 25 (2009) 185-189 189
coefficient G = 2 7 aiid the output am plitude reached 53dB A fterthat w e utilized the W ilkinson bridge
to com bine the tw o output signals T he final am plitude w as 56dB w h e n m easured with the W att M eter Model 4 3 - S ^ 2 8 6 0 7 0
1 1 ,
'C T Í0 C 8 :0;C 5i ;
Fiu 6 ( a ) T h e f r e q u e n c y ch arac teristics; (b ) S p e c t r u m at 1 0 3 0 M H z
5 C o n clusion
\Vc have d esigned, successfully fcibricated and tested th e p o w e r com bination unit using the Wilkinson bridge, i'he expcrimtMital results dem onstrated the efficiency o f this m ethod in
m anuiacluring the larger m odules from the smaller ones and w e anticipa te to applicate this method for
ilie o i i l pn t p o w e r in n e a r f u t u r e
Ackncm n lc g m c n t riie results o f this w ork belong to the research project K C 01.12/06-10 from State Prouranis on Scientific Research o f Vietnam O ne o f these a u th o rs w ould like to thank the support tVom llie research proJcct Ọ T 09-13, V ietnam National University, Hanoi
References
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[4] 3ang I hi Thanh Thuy, !*ham Van Thanh, Nguyen Anh Tuan, Bach Gia D uon g, Research, Design And Fabrication O f
1 he 45W And I hc 2{)()W, I,-Band Power Amplifier Using The M odem Microstrip Technology For Application In The
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