Electrical length while designing a klofenstein taper
I am designing a klophenstein taper but I am stuck as to how to calculate the electrical length. My friend who has calculated the electrical length in another case has me confused.
The following are his specifications please help me figure out how he did it.
Frequency= 2 GHZ
total taper length = 77.8mm
Ee = 3.27 of the dielectric of the microstrip
27 step klofenstein impedance transformer
and the electrical length he calculated or used in his design was 12.5055
If you could tell me how to calculate the electrical length from the given information it would be very helpful.
Cheers in advance
Hello,
Can this be helpful to you: Klopfenstein Taper - Microwave Encyclopedia - Microwaves101.com ?
I know about this page but it does not help in this regard. Please could you help me out.
Given your physical length of 77.8 mm and effective dielectric constant of 3.27 (did you use FR4 with er = 4.4?), I would expect the electrical length to be in the range:
electrical length = 77.8mm*sqrt(3.27) = 141 mm (above the cut-off frequency).
This equals a delay of about 338 degrees at 2 GHz.
It will be somewhat more because of the path along the edge is somewhat longer than the actual length of the taper. Also the effective eps depends on trace width.
What units should be behind your quoted number?
12.5055 is in degrees... is this what you'll get?