Tapered Transmission line match

[jadnounyah]

So I am trying to design a tapered match for a 200 ohm load to a 50 ohm characteristic impedance, and I am supposed to start with quarterwave lines and later reduce the lengths. Now the concept I am aware of the using the same length but different impedances for the tappered match, I was hoping I could be introduced to resources for both varied lengths and impedances for the taper sections for matching. I am using ADS for the design by the way( if it helps anything).

 

[D.A.(Tony)Stewart]

What specs? f , BW

 

[FvM]

I was hoping I could be introduced to resources for both varied lengths and impedances for the taper sections for matching.

To achieve what?

 

[vfone]

Before achieving particular specs, think what kind of topology of tapered match to use.
Abrupt width changes, will increase the radiation loses of the structure. The type of tapering reduce the discontinuity effects.

 

[D.A.(Tony)Stewart]

The max/min f will have some effect of your choices. I wonder if a 2:1 transformer with a much higher SRF would be best for a wide spectrum.

What are your specs?

 

[volker@muehlhaus]

and later reduce the lengths

You mean something like the Klopfenstein taper?

Microwaves101 | Klopfenstein Taper

Microwaves101 | Klopfenstein Taper

www.microwaves101.com

A Transmission Line Taper of Improved Design

The theory of the design of optimal cascaded transformer arrangements can be extended to the design of continuous transmission-line tapers. Convenient relationships have been obtained from which the characteristic impedance contour for an optimal transmission-line taper can be found. The...

ieeexplore.ieee.org

 

[jadnounyah]

What specs? f , BW

the frequency of operation is 3 GHz and, I want the lower bandwidth of operation to be from to be 1 GHz, since tapered matching produces a wide bandwidth which would eventually cover the center frequency of interest. I looked up linear, exponential and klopfenstein tapers but they all seem to have a fixed length and varying impedances for their segments for the match, but I am working on a project and the requirement is the vary the length of the line along the sections.

--- Updated Feb 7, 2024 ---

To achieve what?

to achieve resistive matching, at wide bandwidth matching with center frequency of 3 GHz using any tapering matching technique that affords me the freedom to vary both the impedance and length of the transmission lines along the sections of the tape during matching. The load is 200 ohm to a 50 ohm line. Thank you

--- Updated Feb 7, 2024 ---

Before achieving particular specs, think what kind of topology of tapered match to use.
Abrupt width changes, will increase the radiation loses of the structure. The type of tapering reduce the discontinuity effects.

So far I've come into contact with the middle one, the multi section transformer design, I plan on changing the width (impedance) of the transmission lines uniformly across the various sections to obtain a match so I think I would avoid that increase the radiation loss. I've said the specs I know of in the replies too.

--- Updated Feb 7, 2024 ---

The max/min f will have some effect of your choices. I wonder if a 2:1 transformer with a much higher SRF would be best for a wide spectrum.

What are your specs?

Oh well I have already done the coaxial transformer match, now I'm focusing on the multi section transformer using the taper technique. The center frequency is 3 GHz and I would like a min bandwidth of 2 GHz considering the function of tapers in broadband matching networks. The rest of the specs can be found in the replies. Thank you.

--- Updated Feb 7, 2024 ---

You mean something like the Klopfenstein taper?

Microwaves101 | Klopfenstein Taper

Microwaves101 | Klopfenstein Taper

www.microwaves101.com

A Transmission Line Taper of Improved Design

The theory of the design of optimal cascaded transformer arrangements can be extended to the design of continuous transmission-line tapers. Convenient relationships have been obtained from which the characteristic impedance contour for an optimal transmission-line taper can be found. The...

ieeexplore.ieee.org

yes please something like that, I haven't yet read Klopfenstein's paper but from the theory I've garnered from some books I've read, it seems( speculation) that it is possible for fixed lengths of the sections whiles the width(impedance) of the sections can be varied. But per what I am looking for, the klopfenstein taper won't hold out for me. That's why I am looking for other suggestions on what I actually aim to do even with my specs for the design( it's in the replies)

 

[D.A.(Tony)Stewart]

7.5: Tapered Matching Transformers

eng.libretexts.org

Before you choose a design define your expectations for matching where one has MPT yet with minimal losses and equal ripple in the passband. Can you define this?

 

[jadnounyah]

7.5: Tapered Matching Transformers

eng.libretexts.org

Before you choose a design define your expectations for matching where one has MPT yet with minimal losses and equal ripple in the passband. Can you define this?

Yhyh I have checked this out but i can define the minimum return over which bandwidth I want to obtain after matching. Is that enough? I have read the book itself on the match though.

 

[biff44]

in many cases, a tapered line will give your virtually the same response as a series of quarter wave transmission line impedance transformers.
and there are plenty of papers out there that tell you the optimal impedance of each section. Look up the book by Matthei, Young, and Jones.

tapers are really only useful in things like waveguides, where machining the quarter wave sections gets tricky due to sharp edges/parasitic reactances.