Could anyone please provide a link explaining dc resistance of a microstrip line?
Thanks in advance
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I found this paper useful.
A.R. Djordevic and T. K. Sarkar, "Closed-form formulas for frequency dependent resistance and inductance per unit length of microstrip and strip transmission lines," IEEE Trans. Microwave Theory Tech., vol. 42, pp. 241-248, Feb. 1994
But is the dc resistance almost zero or little under all conditions
While exact solution of frequency dependant resistance is a really difficult problem of theoretical electrical engineering, DC resistance is rather a beginners exercise. Simply consider conductor cross section, length and resistivity.
There, an ideal DC voltage source (= perfect RF short) was used and of course, you can use a lambda/4 transmission line to transform that ideal RF short into a narrowband RF open ciruit. This would not be the equivalent of the resistor circuit, but an alternative solution to feed DC to an RF line. **broken link removed**
In my experience, trace width is 0.5mm, and length is about 40mm, current is about 0.5A, the voltage droped from 5V to 4.8V, so the DC resistance is 0.2V/0.5A/40mm=0.01 ohm/mm @0.5mm width. In my test, there is only DC on the trace, no RF signal.