Wideband Power Splitter/Combiner

[mogwai]

Hello all

I'm looking for design ideas for a wideband power splitter (preferably 90deg phase shift)...

The frequency range of operation is about 500-2000 MHz...

Minicircuits sells the so-called "Super wide bandwidth power splitters (ZN2PD2-50, ZN4PD1-50)" and has an application note pointing out that:

These power splitters use micro strip construction and are manufactured on low loss microwave
substrate. These use traditional Wilkinson topology. A number of sections are cascaded to achieve wide band performance

(from **broken link removed**)

Any ideas about this "cascaded" wilkinson topology?

Thanks in advance

cheers!
mogwai.

 

[flatulent]

They start with a splitter with two 70 ohm quarter wave lines joined at one point. This makes the three ports.

The next step in complexity is to replace each of the two 70 ohm quarter wave lines with several each quarter wave lines in tandem with intermediate values of impedance. Read up on impedance matching with multiple quarter wave lines to get the individual values.

There are some variations with resistors across each stage of the sequence of quarter wave lines as well as the usual one across the two output ports.

 

[radiohead]

Look for "Microwave Engineering" from Pozar. This covers the topic

 

[lguancho]

Hi. Take a look at chapter 7 "Microstrip Devices" in the following book" Networks and Devices using Planar Transmission Lines" (by DiPaolo, Franco).




There is a 2 section power divider design. 8)

 

[pewang]

I have another older paper discuss this topic beside this one.it's pitty that I only have a hard copy for that classic paper so only this one is uploaded.

 

[mogwai]

Many thanks to you all for helping me !!!
This info has been very "enlightening" :lol:

cheers!
mogwai.

 

[drwho78]

Has anyone implemented the equations in the "A General Design Formula of Multi-Section Power Divider" in a computer program?

Thanks,
DrWho78

 

[DJ]

I did years ago.

D.J

 

[flyhigh]

Hi,

just a tip for multisection Willkinson. You should take great care to

1. keep sections decoupled
2. model any discontinuity (bends Ts etc) with great care
3. keep the resistors to standard values
4. chose the substrate so that lines are geometrically much longer than resistor dimensions.

If you have many sections all those has little but multiplied influence to final performance. If you don't take these into account, you might end up with serious mismach and no isolation at all!

Regards

flyhigh

 

[drwho78]

I did years ago.

D.J

I am looking a program to perform the calculations for me such as the trace width and resistor values.

Thanks,

DrWho78

 

[DJ]

There are many books (POZAR for example) that show the mathematical expression for more than one wilkinson splitter. I will look tomorrow to find one for you.

D.J

 

[flyhigh]

Hi,

sorry for bothering you again, multisection "by the book" design requires resistors of non-standard value, it has to be optimized for real world resistor values. Of course, design from the book can serve you as a first (and very good) starting point. Than you can use some simulator to optimize your lines.

flyhigh

 

[Lupin]

Hi everyone,

I´m in troubles with a 0-180 degrees hybrid component from 6 to 18 GHz...a stripline configuration coul be appreciated..
Please can anyone give me support?

Best regards
Lupin