spiral inductor

what is the difference between spiral inductor of larger inner radius and smaller inner radius ?
which one has better performance of them ?
any reference paper ??

thanks

Parameters that are affected by different radius of inductor (for same inductance value):
-DC resistance of the inductor
-Capacitance between the inductor turns
-Q-factor (due to substrate loss)
-Series Resonant Frequency (due to different capacitive loss)

Here are a few topologies that can help:
-Variable inner radius (used for wideband chokes)
-Variable trace width (Q-enhancement)

Probably you could find some useful information here:

MODELING OF SPIRAL INDUCTORS AND TRANSFORMERS
Ms Thesis, KANSAS STATE UNIVERSITY

http://www.eece.ksu.edu/vlsi/spiralmod/thesis.pdf