Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

TRL calibration optimal line length

Status
Not open for further replies.
M

modjii

Newbie level 1
Joined
May 17, 2016
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
13
Hi
i am trying to design a fixture for TRL calibration, my working frequency range is 55 to 65 GHz.
i khnow on my pcb i should design different micrrostrip line as a standard line.
and as i know the electrical length of the line should be greater than 20 degrees of lowest frequency of measurement and not more than 160 degrees of the highest frequency.
my substrate has 3.54 permittivity with thickness of 0.508 mm, effective permitivity is 3.28. (50 ohm impedance)
i want to know how many standard line should i have, and what is my lower frequency is it 1 GHz or i should take 50?
should i take the geometric mean between the two; sqrt(55*65)=59.79 GHz and calculate the line length or ?
thx
 

you need to have three lines, thru reflect and delay.

yes, you need to design the line for centre frequency.
 

Lets look it in this way:
The delay is wrt through line std. Through line length is considered to be of zero length ,with both reference planes overlapped.
Now the delay lines must provide phase delay in the range of 30 deg to 150 deg wrt through line.
So,if through line is of lambda/4 length,delay lines must be lenghthier .
One delay line must cover a BW 5:1,i.e. if frequency range to be covered is 1-10 Ghz,then two lines are required 1st will cover 1-5GHz 2nd line will cover 5-10GHz.
So,if line is designed to be 90 deg for center frequency,then it will provide 30 deg delay for lowest and 150 deg for the highest frequency.
In your case one delay line is enough.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top