Whoever has experience on design microstrip coupler?

[Needbias]

whoever has experience on design microstrip 90-degree hybrid(not use lange coupler) for bandwidth of 4:1 or larger,I just want to know how to realize it?thx.

 

[Needbias]

Hi,vividsoft
4:1 means the ratio of highest freq and
lowest freq in the whole band

 

[odyseus]

You best and only bets are to use either

(1) Hybrid ring or rat-race or

(2) Branch line hybrid,

Both will give the required quadrature phase you are after and are normally used for balanced amp and mixers etc..

 

[Mazz]

Yeah odyseus
but with a branch line or a rat race you can achieve a 20% BW. The solution could be find in some articles with that structures modified. But this adds some difficulties in design. I think it is not a simple task.
Mazz

 

[Needbias]

I agree with Mazz's viewpoint.There has some article about how to make a 3-dB microstrip(not stripline) hybrid using modified ratrace
structure with one octove bandwidth but to realize it will have some difficulity.

 

[test140265]

You can use a double branch line hybrid, there are quite good books on the subject,
the bandwidth of the doubble branch line is greater than the 90 deg branch line hybrid so it should fit your needs, if you can not find litterature mail me and i will find it in a few days.

Regards

 

[Needbias]

Thx very much,plz mail to me.

 

[b4bb4ge]

What info do you have on a double branch line coupler will that change the phase and can you get -3db out of both still?

Thanks

 

[jallem]

I have seen a fractal rat race coupler where
the bandwidth is increased.