Need good tutorial/design example on broadband mutistage impedance matching.

A request to all you gurus on this newsgroup. I am looking for a good tutorial, preferably with a design example, on multi-stage broadband impedance matching. Any pointers would be very helpful. Thanks in advance.

Reply to
dakupoto
Loading thread data ...

Books I like: Wes Hayward - Introduction to Radio Frequency Design or Experimental Methods in RF Design.

piglet

Reply to
piglet

As a general rule the broader the impedance match the more components that you need to use. I don't know if you're doing all lumped or loved and distr ibuted or all distributed but nevertheless the concept Remains the Same. If you have a reasonable idea of the source impedance and the load impedance of the two amplifiers you ought to be able to play around with a RF program and empirically get there

Reply to
bulegoge

formatting link

Reply to
makolber

I don't think Chris Bowick handles really broadband matching, unless you think an octave or two is broadband, that is.

If anyone can do significantly better than 3 decades, speak up! I want to talk to you!

Jeroen Belleman

Reply to
Jeroen Belleman
3 decades? A typical amplifier has 60 db gain variation across 3 decades so the only thing that works is feedback. So I am speaking up...learn feedback. Like all of these posts, there is no general answer to a specific problem.
Reply to
bulegoge

Well, transformers. And amplifiers, if you don't require passive solutions.

Broadband impedance matching isn't quite the same as the narrowband case. The circuit needs to be right, by default. Either the circuit is designed around system impedance in the first place, or transformers are used to match it. You can fudge the band edges (both HF and LF), using RLC impedance matching -- filtering -- but only by about an octave.

A principle that applies to the narrowband case as well -- that is, using higher order networks (giving tighter band skirts) to extend bandwidth modestly.

Tim

--
Seven Transistor Labs, LLC 
Electrical Engineering Consultation and Contract Design 
 Click to see the full signature
Reply to
Tim Williams

+1 on "Introduction to Radio Frequency Design" it's a one-stop-shopping book
Reply to
bitrex

It's a little more math-heavy than some other introductory textbooks though so it doesn't hurt to brush up on a bit of calculus/linear algebra before heading in

Reply to
bitrex

I have both and wholeheartedly recommend them.

Reply to
John S

I have his RF Design book and I find it invaluable.

Reply to
John S

Sure. I have it too and it's very nice, but not for broadband matching.

Jeroen Belleman

Reply to
Jeroen Belleman

Not relevant.

I routinely use transmission line transformers to effect impedance matching over three decades of frequency between to real impedance levels. Sometimes, in specific cases, I can stretch that a bit. My record is six decades in a 25 to

100 ohm transformer. (Those are the easiest, usually, but not if you want 6 decades!) I've lost that ability with the demise of the required amorphous metal magnetic cores. Sigh.

Jeroen Belleman

Reply to
Jeroen Belleman

When I am matching 50 ohms to 50 ohms I can match 100 decades with a 50 ohm load cable.

Reply to
bulegoge

Do tell. Even if your cable were good to 100 GHz, 100 decades below that is a good 10**71 times the age of the universe.

Cheers

Phil Hobbs

Reply to
pcdhobbs

You're both posers. I can match 377 ohms to 377 ohms over a 8.0795098 x

10^60 range. :-)

Tim

--
Seven Transistor Labs, LLC 
Electrical Engineering Consultation and Contract Design 
 Click to see the full signature
Reply to
Tim Williams

I was starting at dc and going up. Now i guess your point is that there really isnt dc if you dont wait forever, so point taken.

Reply to
bulegoge

Well, I did impedance-match a 200-THz antenna over about a 40-THz bandwidth, so I win for absolute bandwidth if not fractional. ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
 Click to see the full signature
Reply to
Phil Hobbs

As long as you're not counting optical 'impedance matching'..ie AR coatings.

George H.

Reply to
George Herold

Such a buzzkill. ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
 Click to see the full signature
Reply to
Phil Hobbs

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.