Click here to go to our page on skin depth
Click here to go to our page on the exact calculation of metal loss for coax
This is going to seem hodgepodge for a while. For now we will dump whatever info we can that has to do with wires used as transmission lines onto this page, then sort it out later. How about some contributions from the audience?
Wire over ground
We have a calculator that calculates impedance for this structure, click here!
Twin wires
Coming soon!
Twisted pair
Coming soon!
RF resistance of a wire
Until we get around to presenting the formulae, here is an approximation you can find on another web site (thanks to Dr. S!)
Resistive loss of a wirebond
We modified the coax spreadsheet (available in the download area) to calculate the metal loss of 1-mil diameter bond over frequency (does not include mismatch loss or radiation). It is very low, the plot is in dB/mm, a typical X-band bond is 1mm. The calculation also shows that at DC, 1-mil gold wire has 20 ohms resistance/meter, which
goes up with frequency.
The loss might actually be lower if you took into account that the impedance is transformed by the bondpads to something less than fifty ohms.
