Microstrip Transmission Line Width

Hello,

Could anyone assist in telling me how to find the width of a microstrip transmission line?
I know there are formulas and some calculators online but they all seem to require some initial width anyway.

Thanks!

4 variables, 3 known + solve.
http://www.microwaves101.com/calcula...ine-calculator

Microstrip line usually related with impedance. Also some parameters like substrate height, frequency and dielectric constant. I suggest using following.
http://www.emtalk.com/mscalc.php
for more accurate u can use
http://www1.sphere.ne.jp/i-lab/ilab/tool/ms_line_e.htm

many closed form formulas..depends on which characteristic impedance you are trying to implement

Impedance is chiefly dependent on track width to gap ratio and dielectric constant,D.

• Thinner boards allow smaller tracks at the same ratio and impedance.
• D tends to have a 10% minimum tolerance.
• Track widths have an etch-back tolerance equal to thickness of copper.
• Impedance testing by TDR method is done at fab shop on test coupons at additional expense for better results and D codes adjusted in Gerber file.
• Slight variations exist due to dielectric constant reducing with rising f , conductor skin effects and gap to wavelength ratio at EHF.

You can use this links to design or synthesis microstrip transmission lines, all links use closed-form expressions.

http://www1.sphere.ne.jp/i-lab/ilab/tool/ms_line_e.htm

http://www.eeweb.com/toolbox/microstrip-impedance

http://chemandy.com/calculators/micr...-hartley27.htm

http://www.finetune.co.jp/~lyuka/technote/ustrip/

good luck.



also you can use Line-Calc option in ADS software!

hamid did you verify all calculators give the same results?

SunnySkyguy it is assumed we want to synthesis a 50-ohm microstrip transmission line,
consider er = 4.4, h (height) = 1.6 mm, freq = 1000 MHz, and t (thickness of trace) = 0.001 mu m.

result by http://www1.sphere.ne.jp/i-lab/ilab/tool/ms_line_e.htm
W = 3.045654296875 mm

http://www.eeweb.com/toolbox/microstrip-impedance gave me Z0 = 50.1 ohm

http://chemandy.com/calculators/micr...-hartley27.htm gave me Z0 = 50.22 ohm

Result for http://www.finetune.co.jp/~lyuka/technote/ustrip/
W = 3.0508791326846296

there is a good agreement between all results.