Hi all,
Quote:Are you sure about that? That looks like quite an old paper. If I remember correctly, several of Prof. Razavi's later 60 GHz works used inductors. Anyway, to be safe, t-lines may be a better choice.
Quote:thanks for your reply but I have read that spiral inductors become too complex at higher freqs( 40ghz and above ) and their models for no longer are accurate
yes you are quite right...
Quote:your EM modeling will probably need to be much more accurate for spiral inductors
One problem which applies to both spiral inductors and t-lines is you need to make sure to properly define where the inductor starts and ends. Otherwise the parasitic inductance could be on the same order of magnitude as the designed inductance. For spiral inductors, coupling to nearby metals and other inductors may be stronger, meaning that you will need to do some kind of multi-port EM simulation to include all major structures. Equally important is the return path...
Quote:Another consideration is the return path which should be much better defined for a transmission line than inductors.
It is important to have a well-defined return path to prevent unwanted interaction between different stages in the circuit.
regards,
Aaron