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Wilkinson power divider

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mudrik

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dear all,

at the moment we build a broadband power divider.
The wilkinson type needs a resistor say 100 ohms.
what kind of resistor is it?
Is it easy to get it, maybe as samples from vendors

thanks and regards
 

Element_115

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Just make sure it is small as possible (Assuming Fo>1Ghz) and that
it can handle the power(~2-3 times the Average Output Power).

Cheers
 

BiH

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hi all,

I am doing a 2-section wilkinson power divider having impedances Z1=83.677 and Z2=59.755 respectively. Characteristic impedance of the system is 50 Ohms. The values of the impedances of each section are obtained using some exe application. Can someone help with the calculation of the resistor values. Is there any formula to get them???

thanks
 

enjunear

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hi all,

I am doing a 2-section wilkinson power divider having impedances Z1=83.677 and Z2=59.755 respectively. Characteristic impedance of the system is 50 Ohms. The values of the impedances of each section are obtained using some exe application. Can someone help with the calculation of the resistor values. Is there any formula to get them???

thanks

R2 = (2*Z1*Z2) / sqrt((Z1+Z2)*(Z2-Z1*cot^2(phi3)))
R1 = (2*R2*(Z1+Z2)) / (R2*Z1+Z2)-2*Z2)
phi3 = 90deg * (1- (1/sqrt(2))*((f2/f1 - 1) / (f2/f1 + 1)))
where f2/f1 is the bandwidth.

R1 is located between the output legs of the combiner, R2 is located 1/4-wave from the input.

For example: for f2/f1 = 4
R1 = ~165
R2 = ~138
Z1 = ~120
Z2 = ~143

The equations can be found in Stripline Circuit Design, by Harlan Howe, a book I'd highly recommend for any mcirostrip/stripline designer.

---------- Post added at 10:42 ---------- Previous post was at 10:28 ----------

dear all,

at the moment we build a broadband power divider.
The wilkinson type needs a resistor say 100 ohms.
what kind of resistor is it?
Is it easy to get it, maybe as samples from vendors

thanks and regards

Typically you'd use a thick/thin-film resistor (very low paracitics, looks more like a pure resistance). Keep it as short as possible (small fractions of a wavelength at Fo)... the more phase length it has, the worse your isolation will become.

From a theoretical standpoint, you want it to handle at a minimum 1x the average input power. You can either derate the power handling for temperature, or just go 2-3 times the average power and play it safe.

Depending on your power level, look at most any SMT film chip resistor manufacturer. Try Digikey, Mouser, Newark for a wide selection of parts for very cheap (shipping may cost more than the parts, so find the part you want, then request samples directly from the manufacturer).
 

btv_murthy

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you may use the THIN FILM RESISTOR.I don't know also ,how to find width and thickness of TFR.
 

enjunear

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you may use the THIN FILM RESISTOR.I don't know also ,how to find width and thickness of TFR.

The thickness of the material is determined by the shop that plate-up the PCB. They will put it down in thicknesses corresponding to whatever ohms-per-square (ohms/sq) you desire. Most people use 50, 100 or 25 ohms/sq. The length and width should be determined from the final resistor value you desire. R = Rs*L/W, where the TFR's resistance = Resistance of the sheet (50 ohms/sq) * Length/Width. E.g. for a 100 ohm resistor on 50 ohms/sq, your length will need to be 2x the width.
 

Galilee

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btv_murthy

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Dear Galilee sir,
what values for TFR length and width i need to substitute my circuit to get the S parameters S(3,2) values more than -24DB.Present value i am getting -7DB. I am expecting the S(3,2) value as more than -24db. can u help me how to get S(3,2) as more than -24 DB.
 

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  • 4 WY_WILKINSON.jpg
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btv_murthy

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Volker sir,

Here with I am attacing schematic and layout of 4 wy Wilkinson power divider, Previous you replied , as you replied there is something wrong with your extraction and layout. I am attacing both ,I couldn't find out where I have done mistake. Design values for 4 wy Wilkinson power divider are as follows

Z(characterstic impedence) = 50 ohm, f = 3GHz, H=1.6mm, T = 0.036, relative permitvity = 4.4, tangential loss =0.001

I am expecting s- parameter values for above design values as follows for both schematic EM simulation

S(1,1) S(2,1) S(3,1) S(3,2)

-34 DB -3.0412DB -3.0412DB, -34DB
Presentently, I am getting the following values for attaching layout and schematic

S(1,1) S(2,1) S(3,1) S(3,2)

-19.185DB, -3.4554DB, -3.4554DB, -7.129DB

Volker sir, please tell me how to get the expected results, please sir you try to make changes as you wish and attach the both schematic and layout for correct values obtained to you sir,Please try to solve this problem . If you have other schematic for above design values please send me sir, Sir I request you to make changes to my schematic and layout , send the expected values obtaind schematic and layout diagram sir.
I will be greatful to you sir.
 

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  • wilkinson layout.png
    wilkinson layout.png
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btv_murthy

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Volker sir,
Here with I am attacing schematic and layout of 4 wy Wilkinson power divider, Previous you replied , as you replied there is something wrong with your extraction and layout. I am attacing both ,I couldn't find out where I have done mistake. Design values for 4 wy Wilkinson power divider are as follows
Z(characterstic impedence) = 50 ohm, f = 3GHz, H=1.6mm, T = 0.036, relative permitvity = 4.4, tangential loss =0.001
I am expecting s- parameter values for above design values as follows for both schematic EM simulation
S(1,1) S(2,1) S(3,1) S(3,2)
-34 DB -3.0412DB -3.0412DB, -34DB
Presentently, I am getting the following values for attaching layout and schematic
S(1,1) S(2,1) S(3,1) S(3,2)
-19.185DB, -3.4554DB, -3.4554DB, -7.129DB
Volker sir, please tell me how to get the expected results, please sir you try to make changes as you wish and attach the both schematic and layout for correct values obtained to you sir,Please try to solve this problem If you have other schematic for above design values please send me sir, Sir I request you to make changes to my schematic and layout , send the expected values obtaind schematic and layout diagram sir.
I will be greatful to you sir.
 

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  • wilkinson layout.png
    wilkinson layout.png
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  • 4 WY_WILKINSON.jpg
    4 WY_WILKINSON.jpg
    116.3 KB · Views: 32

V

volker_muehlhaus

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as you replied there is something wrong with your extraction and layout. I am attacing both ,I couldn't find out where I have done mistake.

As already posted multiple times: If you have set Rs=100 Ohm, your "long" resistor with length/width = ~10 will have ~1kOhm resistance, instead of the 100 ohm that we want.
 

btv_murthy

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Volker Sir,
Sir I got the expected results for 4 way wilkinson power divder, I followed as you said. I am very greatful to you sir, you helped more sir.I am realy very greatful to you sir.What ever you told that formula,I used that formula and did some settings changes of EM Extraction. By the *** grace you guided through the email, I am realy thankful to you sir. I am Ph.D student in one INDIAN university.If I need further help, I will contact you sir.

With regards
B.T. VENKATESH MURTHY,
Ph.D scholar,
ASST PROFESSOR,
SCHOOL OF ELECTRONICS ENGINEERING,
VIT UNIVERSITY,
VELLORE,
TAMILNADU(STATE),
INDIA.
MOBILE NUMBERS:+919741568963.
+919626382158.
EMAIL ID: btv_murthy@rediffmail.com
 

btv_murthy

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How to find the radius of curvature for MCURVE for the 180 hybrid coupler

Dear volker Sir,

You hepled me earlier lot, I have one more problem sir,
I don't know,how to find the value of RADIUS OF CURVATURE value of MCURVE of Hybrid coupler. Presently I am getting the S-PARAMETER values for the 180 deg HYBRID COUPLER as follows for both schematic and EM simulation.

for schmatic simulation S(1,1), S(2,1), S(3,1), S(4,1) for EM SIMULATION S(1,1), S(2,1), S(3,1), S(4,1)

-6.3478DB, -5.2062DB, -10.707DB, -6.7046DB 6.3478DB, -5.2062DB, -6.7046DB, -10.707DB
I am expecting the following values.

for schmatic simulation S(1,1), S(2,1), S(3,1), S(4,1) for EM SIMULATION S(1,1), S(2,1), S(3,1), S(4,1)

-34 DB, -3.001DB, -3.001DB , -34DB -34 DB, -3.001DB, -3.001DB , -34DB

I am here wtih attaching the schematic ,layout and related document. Please help me any body to resolve this problem.
 

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  • Hybrid coupler.jpg
    Hybrid coupler.jpg
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  • Hybrid coupler layout.jpg
    Hybrid coupler layout.jpg
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  • 10-180 HYBRID COUPLER.doc
    198 KB · Views: 14

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