# Two-Stage Wilkinson Power Combiner - RF Cafe Forums

The original RF Cafe Forums were shut down in late 2012 due to maintenance issues. Original posts:

guest
Post subject: two-stage Wilkinson Power Combiner Posted: Thu Apr 14, 2005 11:34 am
I'm trying to build a power combiner at 75 Ohms and at the frequency range of 950-2025 MHz. I thought I would use a simple Wilkinson power combiner but since my bandwidth is so large I don't think that will perform well. I did some investgating and found out that by adding a second set of quarter-wave sections to the Wilkinson power combiner that you increase the bandwidth. However, I do not know the equations to calculate the impedances of all the quarter-wave lines or the two resistors. Can anyone give me those equations or point me to a sight or book that has them?

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Guest
Post subject: Posted: Thu Apr 14, 2005 3:57 pm
Hello,

The general equation for quarter wavelength transformer is the geometric average of the 2 impedances that you want to match: sqrt (Z1*Z2).
You can choose the impedances you want to and then calculate the transformer's impedance.

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Guest
Post subject: Posted: Fri Apr 15, 2005 9:21 am
Quarter wave transformer will only give 20% at best although there are designs for wide band transformers but it will be rather large. You can design a wideband wilkinson power divider. As far as the equations, I think that it may be on the RFcafe site, not sure of the link, bu tmaybe Kirt knows. Also, try google. I have a paper ( somewhere) , If I find it I will post the equations. Kirt is there a way to post a paper in PDF format on the site?

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Guest
Post subject: Posted: Fri Apr 15, 2005 9:32 am
There is a paper on it. Seymour B. Cohn, " A Class of Broadband Three-Port TEM Mode Hybrids", IEEE Transactions, MTT-16 NO 2 , Feb 1968. If I knew how to post the paper I would.

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Guest
Post subject: Posted: Sun Apr 17, 2005 9:34 am
Anonymous wrote:
There is a paper on it. Seymour B. Cohn, " A Class of Broadband Three-Port TEM Mode Hybrids", IEEE Transactions, MTT-16 NO 2 , Feb 1968. If I knew how to post the paper I would.

Hi!
I am another person who read your reply. I am interested in the subject of Wilkinson power diwider. Can you e-mail me the paper. My e-mail address is: m_samii@noavar.com.

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Guest
Post subject: Posted: Tue Jul 19, 2005 4:38 am
Guest wrote:
Anonymous wrote:
There is a paper on it. Seymour B. Cohn, " A Class of Broadband Three-Port TEM Mode Hybrids", IEEE Transactions, MTT-16 NO 2 , Feb 1968. If I knew how to post the paper I would.

Hi!
I am another person who read your reply. I am interested in the subject of Wilkinson power diwider. Can you e-mail me the paper. My e-mail address is: m_samii@noavar.com.

Hi
I am another person who intersted to have this paper too,can any of u send that to me
my email is prober_a@yahoo.com

Posted  11/12/2012

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