What's the name of these 'trapezoidal metal' strip??

[hskw_ha]

Hello, threader
I'm studying on RF, MMIC such things...

I found very unfamiliar metal strip line which looks like a trapezoid (Blue arrow in the picture)
I can't found any hint about this metal shape on RF bible/textbook

Does anyone could answer to me what it is?

This picture is presented on academic IEEE paper
"Accurate Offset Line Design of Doherty Amplifier With Compensation of Peaking Amplifier Phase Variation"
IEEE Trans. MTT Vol. 64 No. 10, Oct. 2016

 

[volker@muehlhaus]

I think these are alternative routing paths, which can be enabled with copper strips, if the original line is cut away. Purpose: make the line length longer or shorter when tweaking the prototype layout.

 

[biff44]

^exactly. they are ling length adjusters.

the signal splits into two paths, and for some reason you might need to phase balance the two outputs. is it an I/Q mixer, for instance, and you adjust the line lengths to achieve unwanted sideband supression?