[SOLVED] Suspended Stripline Divider /Combiner deisgn

[shashy.br]

Hi all,

I need to design a Suspended strip line hybrid Divider and Combiner for 8 to 10GHz ,

Please let me know if any literature on the design is available.!

please let me know is any other method of combining is recommended for the X band.

 

[G4BCH]

I assume you just need a simple equal power in phase combiner.
Google for Wilkinson combiner and suspended substrate transmission line. There should be plenty of information to help you.
Avago ApccCAD can be used to help you work out the dimensions for the transmission lines. Depending on the performance you need you may need to optimise the design with an EM simulatior to account for discontinuities.
Peter

 

[shashy.br]

Hi G4BCH,

Thanks for replying

I need a Hybrid Divider and Combiner !!!

I tried searching the Internet for the 10GHz suspended strip line Hybrid Combiner and Dividers but i couldn't find any helpful article.

 

[G4BCH]

A hybrid splitter/combiner means that the device is 'lossless' and provides some isolation between the ports i.e. not just 3 resistors. It can be equal power or unequal power, in phase, out of phase or quadrature phase. So you question is too vague to be answered easily.
A wilkinson combiner is a hybrid combiner that in its simplest form is an equal power in phase combiner. The most common form.
goto https://www.microwaves101.com/ there are number of cacluators there that will help you out in designing a number of microwave circuits and sytems.
Don't be too specific on your searches you will be very lucky to find a ready made design for what you want. The inforamtion and tools are there to find out how do it for yourself. I would start by searching for wilkinson combiner then when you have a basic design progress to suspended subrate to get the dimensions you will need.
If you need a quadratrure combiner then a 'rat race' combiner or lange coulpler is what you need.

Peter

 

[tony_lth]

At X-band, microstrip can work finely and is easier. Why do you select suspended substrate?

 

[shashy.br]

G4BCH,

Thank you for the link.

tony_lth,

I designed a Hybrid power combiner using Micro strip approach, i am looking for other options for power combining .

Please let me know if the X band power combiner can be done using Suspended strip line , or is there any issue while designing the same ?

 

[G4BCH]

Suspended subrate is mechanically more difficult to impliment, needing upper and lower grounds and connection to them at the interface.
It will have lower loss ther being less or no solid dielectric. This may be important for high power applications.
Unless you have small groundplane spacing the trackwidths get rather large.
If there is no real need to use suspended subrate, like Tony-lth I would stick with microstrip.

Peter

 

[shashy.br]

Mr Peter,

do you mean that the Strip line configuration will have a lower loss compared to the Micro strip configuration,

My application is a High power application and i am going to generate the output of 300 Watts using power amplifiers.

Even a slight difference in the losses encountered will be of great help.

 

[G4BCH]

300 watts at X band is serious power and not something to be undertaken lightly.
If you are having to ask about how to design something as simple as a hybrid combiner you are going to need far more assistance than than any one here will be able to give you in designing an amplifier like that. A successful design requires a lot of experience in microwave design, power supply design and thermal management. You will need to ask someone loacally to help you out.
At that power level you be combining a number, probably 4 amplifiers, and it may be better to do this in waveguide.

Peter

 

[shashy.br]

Mr Peter,

Thanks for the Insight !!!

I will look for the wave guide solutions also.

 

[biff44]

suspended stripline, with air above and below, has no means for removing heat from the PCB. I suspect the thing would melt at 300 watts CW!

A stripline coupler might handle the power. Waveguide will definitely handle it.

 

[shashy.br]

Hello,

I am going ahead with a wave guide combiner solution for saving time,

thank you all for sharing your knowledge.