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Design >> RF Design >> TSMC 0.18 components
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Message started by sandman on Dec 25^th, 2006, 1:34pm

Title: TSMC 0.18 components
Post by sandman on Dec 25^th, 2006, 1:34pm

Hi,

I'm implementing a RF front end at a very low level of power consumption. While I was working on a inductive-source degenerated LNA, I realised that I would require a large inductance (>15nH), given an TSMC 0.18 technology.

During my simulations to find L, R and Q of an inductor, I found that the inductor's L value peaks at a certain frequency. Thankfully, this frequency is also the one I'm working with. This L value is larger than it's value at low freq (say 1Hz) byt a factor of 2. (11nH@1Hz and 22nH@my_frequency_of_interest). I was wondering if this value/simulation result is a reliable one or if anyone has had a similar experience. The simulations were performed in ADS and Cadence.

Any help is appreciated.

Cheers,
Sandman.

Title: Re: TSMC 0.18 components
Post by ACWWong on Dec 27^th, 2006, 5:23am

Yes, inductance value for spirals does typically peak, but the peak usually occurs much past the peak Q frequency... so although you get higher L value your Q is much degraded so as to limit the effective impedance if resonanted. As a result I personally have never designed using the peak L value of a spiral inductor in my designs.
cheers
aw

Title: Re: TSMC 0.18 components
Post by sandman on Dec 28^th, 2006, 12:12pm

Thanks for your inputs, aw.