	US 11,811,139 B2
	Gradient permittivity film
Jaewon Kim, Woodbury, MN (US); Stephen J. Etzkorn, Woodbury, MN (US); Ronald D. Jesme, Plymouth, MN (US); Dipankar Ghosh, Oakdale, MN (US); Mohsen Salehi, Woodbury, MN (US); Guanglei Du, Horseheads, NY (US); and John A. Wheatley, Stillwater, MN (US)
Assigned to 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
Appl. No. 17/043,432
Filed by 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
PCT Filed Apr. 4, 2019, PCT No. PCT/IB2019/052760 § 371(c)(1), (2) Date Sep. 29, 2020, PCT Pub. No. WO2019/193530, PCT Pub. Date Oct. 10, 2019.
Claims priority of provisional application 62/654,137, filed on Apr. 6, 2018.
Prior Publication US 2021/0021050 A1, Jan. 21, 2021
Int. Cl. H01Q 15/10 (2006.01); H01Q 1/32 (2006.01); H01Q 1/42 (2006.01)

CPC H01Q 15/10 (2013.01) [H01Q 1/3233 (2013.01); H01Q 1/3283 (2013.01); H01Q 1/422 (2013.01)]

19 Claims

1. A gradient permittivity film having a first major surface and an opposing second major surface, comprising: a plurality of layers each having a thickness; wherein at least one layer of the plurality of layers is a perforated layer characterized by an average border thickness surrounding each perforation and an average pitch between the centers of each perforation, and an air volume fraction averaged over the thickness of the perforated layer; wherein the perforated layer has a different air volume fraction from another of the plurality of layers by at least 0.05, and wherein each perforation has a perforation axis along the center of each perforation, and at least one perforation has a canting with respect to a thickness direction of the perforated layer, the canting defined by the perforation axis, and the perforation axis varies between two or more perforations along one or more non-thickness directions.