Generating Variable Inductances by Altering the Physical Characteristics of Inductors Connected in Parallel

Abstract

CMOS LC tank circuits and flux linkage between inductors can be used to distribute and propagate clock signals over the surface of a VLSI chip or μprocessor. The tank circuit offers an adiabatic behavior that recycles the energy between the reactive elements and minimizes losses in a conventional sense. The LC tank circuit contains a plurality of inductors coupled together in parallel. The area encompassed within each of these inductors can be altered causing the inductors coupled in parallel to have a variable self-inductance.

1 . A method of varying a self-inductance of inductors coupled in parallel by altering an area encompassed by each of the inductors that form the inductors coupled in parallel, comprising the steps of:
 forming a plurality of inductors on a substrate:   assigning a first inductor of the plurality of inductors to have a reference self-inductance;   connecting at least one additional inductor from the remaining plurality of inductors in parallel to the first inductor; thereby,
 forming the inductors coupled in parallel; 
   determining that the self-inductance of the inductors coupled in parallel is less than the reference self-inductance; and,   altering the area encompassed by each of the inductors coupled in parallel causing the self-inductance of the inductors coupled in parallel to vary; thereby,   varying the self-inductance of the inductors coupled in parallel by altering the area encompassed by each of the inductors that form the inductors coupled in parallel.   
     
     
         2 . The method of  claim 1 , wherein:
 the area encompassed by the inductors coupled in parallel is increased causing the self-inductance of the inductors coupled in parallel to increase.   
     
     
         3 . The method of  claim 1 , wherein:
 the area encompassed by the inductors coupled in parallel is decreased causing the self-inductance of the inductors coupled in parallel to decrease.   
     
     
         4 . The method of  claim 1 , further comprising the steps of:
 defining a first encompassed area as the area encompassed by the first inductor; and,   summing the encompassed areas of the inductors coupled in parallel to form a total encompassed area.   
     
     
         5 . The method of  claim 4 , wherein:
 the total encompassed area is greater than the first encompassed area.   
     
     
         6 . The method of  claim 4 , wherein:
 the total encompassed area is substantially equal to the first encompassed area.   
     
     
         7 . The method of  claim 4 , wherein:
 the total encompassed area is less than the first encompassed area.   
     
     
         8 . The method of  claim 1 , wherein:
 the self-inductance of the inductors coupled in parallel is greater than the reference self-inductance.   
     
     
         9 . The method of  claim 1 , wherein:
 the self-inductance of the inductors coupled in parallel is substantially equal to the reference self-inductance.   
     
     
         10 . The method of  claim 1 , wherein:
 the self-inductance of the inductors coupled in parallel is less than the reference self-inductance.   
     
     
         11 . The method of  claim 1 , further comprising the steps of:
 magnetically coupling at least two inductors of the inductors coupled in parallel to each other.   
     
     
         12 . The method of  claim 1 , wherein:
 the area encompassed by each of the inductors forming the inductors coupled in parallel is varied independently of one another.   
     
     
         13 . The method of  claim 1 , wherein:
 the area encompassed by each of the inductors forming the inductors coupled in parallel is increased uniformly.   
     
     
         14 . The method of  claim 1 , wherein:
 the area encompassed by each of the inductors forming the inductors coupled in parallel is decreased uniformly.   
     
     
         15 . The method of  claim 1 , wherein:
 each of the inductors forming the inductors coupled in parallel occupy different layout regions of the substrate.   
     
     
         16 . The method of  claim 15 , wherein:
 an extension leg is added to at least one inductor of the inductors coupled in parallel to physically separate the inductors coupled in parallel.   
     
     
         17 . The method of  claim 1 , wherein:
 at least two of the inductors from the inductors coupled in parallel occupy the same layout region of the substrate.   
     
     
         18 . The method of  claim 1 , wherein:
 the inductors are planar.   
     
     
         19 . The method of  claim 18 , wherein:
 the inductors coupled in parallel are patterned using at least one metal layer.   
     
     
         20 . An apparatus, comprising:
 a plurality of planar inductors formed on a substrate;   a first inductor of the plurality of planar inductors has a reference self-inductance;   a first encompassed area of the first inductor which is defined as a reference area;   at least one of the remaining plurality of planar inductors is coupled in parallel to the first inductor forming inductors coupled in parallel;   a self-inductance of the inductors coupled in parallel;   a total encompassed area formed by summing the encompassed area of each of the inductors in the inductors coupled in parallel;   the total encompassed area is equal to or greater than the reference area; and,   the self-inductance of the inductors coupled in parallel is less than the reference self-inductance.   
     
     
         21 . The apparatus of  claim 20 , wherein:
 at least two of the inductors coupled in parallel are magnetically coupled to each other.   
     
     
         22 . The apparatus of  claim 20 , wherein:
 at least two of the inductors selected from the inductors coupled in parallel occupy a common layout region of the substrate.   
     
     
         23 . The apparatus of  claim 20 , wherein:
 each the planar inductors selected from the inductors coupled in parallel have substantially the same encompassed areas.   
     
     
         24 . The apparatus of  claim 20 , wherein:
 each the planar inductors selected from the inductors coupled in parallel have different encompassed areas.   
     
     
         25 . The apparatus of  claim 20 , wherein:
 the planar inductors selected from the inductors coupled in parallel each occupy different layout regions of the substrate.   
     
     
         26 . The apparatus of  claim 25 , wherein:
 the planar inductors each have an extension leg to further separate the planar inductors from one another on the substrate.   
     
     
         27 . The apparatus of  claim 20 , wherein:
 the planar inductors in the inductors coupled in parallel have equal trace widths.   
     
     
         28 . The apparatus of  claim 20 , wherein:
 at least one the planar inductors in the inductors coupled in parallel has a different trace width than the remaining inductors selected from the inductors coupled in parallel.   
     
     
         29 . The apparatus of  claim 20 , wherein:
 the planar inductors are patterned using at least one metal layer formed in the substrate.   
     
     
         30 . A method of increasing a self-inductance of inductors coupled in parallel, comprising the steps of:
 forming a plurality of inductors on a substrate;   assigning a first inductor of the plurality of inductors to have a reference self-inductance;   coupling at least one of the remaining inductors of the plurality of inductors in parallel to the first inductor to form inductors coupled in parallel where the inductors coupled in parallel has a self-inductance that is less than the reference self-inductance; and,   increasing the area encompassed of the inductors coupled in parallel to increase the self-inductance of the inductors coupled in parallel with respect to the reference self-inductance; thereby,   increasing the self-inductance of inductors coupled in parallel.   
     
     
         31 . A method of increasing an encompassed area of a parallel-connected inductor network, comprising the steps of:
 establishing a plurality of inductors on a substrate;   assigning a first inductor of the plurality of inductors to have a reference self-inductance;   setting the encompassed area of the first inductor as a reference area;   connecting at least one of the plurality of inductors in parallel to the first inductor forming the parallel-connected inductor network;   increasing the area encompassed by the parallel-connected inductor network until a self-inductance of the parallel-connected inductor network equals the reference self-inductance; thereby,   increasing the encompassed area of the parallel-connected inductor network.   
     
     
         32 . An apparatus, comprising:
 a plurality of inductors on a substrate;   a first inductor of the plurality of inductors to have a reference self-inductance;   an encompassed area of the first inductor is set as a reference area; and;   at least one of the remaining plurality of inductors are coupled in parallel to the first inductor; wherein,
 the encompassed area of the parallel-connected inductors is increased causing an increase in the self-inductance of the parallel-connected inductors.