Method for the manufacture of a spatially varying dielectric material, articles made by the method, and uses thereof
A stereolithography method of manufacture of a polymer structure having a spatially gradient dielectric constant, including: providing a volume of a liquid, radiation-curable composition; irradiating a portion of the liquid, radiation-curable composition with activating radiation in a pattern to form a layer of the polymer structure; contacting the layer with the liquid, radiation-curable composition; irradiating the liquid, radiation-curable composition with activating radiation in a pattern to form a second layer on the first layer; and repeating the contacting and irradiating to form the polymer structure, wherein the polymer structure comprises a plurality of unit cells wherein each unit cell is integrally connected with an adjacent unit cell, each unit cell is defined by a plurality of trusses formed by the irradiation, wherein the trusses are integrally connected with each other at their respective ends, and the trusses of each unit cell are dimensioned to provide the spatially gradient dielectric constant.
1. A polymer structure having a spatially gradient dielectric constant, the polymer structure comprising:
a unified body of dielectric material comprising an open-lattice cell structure comprising a plurality of unit cells, wherein each unit cell is integrally connected with an adjacent one of the unit cells;
wherein an average dielectric constant of the unified body of dielectric material varies from a portion of the body to another portion of the body; and
wherein the spatially gradient dielectric constant of the polymer structure has endpoints in a range from 20 to greater than 1, measured at 10 GHz, 23° C., and 50% relative humidity.
2. The polymer structure of claim 1 , wherein the average dielectric constant of the unified body of dielectric material decreases in a direction from an internal portion of the body to an outer portion of the body.
3. The polymer structure of claim 1 , wherein the average dielectric constant of the unified body of dielectric material varies periodically from a first portion of the body to a second portion of the body.
4. The polymer structure of claim 1 , wherein the spatially gradient dielectric constant of the unified body of dielectric material is from 10 to greater than 1, measured at 10 GHz, 23° C., and 50% relative humidity.
5. The polymer structure of claim 1 , wherein the spatially gradient dielectric constant of the unified body of dielectric material is from 5 to greater than 1, measured at 10 GHz, 23° C., and 50% relative humidity.
6. The polymer structure of claim 1 , further comprising at least one electrical conductor disposed in contact with the unified body of dielectric material.
7. The polymer structure of claim 1 , wherein each of the unit cells has size of less than 30% of a wavelength of an electromagnetic wave in which the polymer structure is operable.
8. The polymer structure of claim 1 , wherein the spatially gradient dielectric constant comprises a step gradient.
9. The polymer structure of claim 1 , wherein the spatially gradient dielectric constant comprises a continuous gradient.
10. An electronic device comprising the polymer structure of claim 1 , wherein the unified body of dielectric material forms at least part of an impedance-matching layer, a dielectric waveguide, a lens, a reflect array, an antenna matching structure, a superstrate, a coupler, a divider, or a dielectric antenna.
11. The electronic device of claim 10 , wherein the unified body of dielectric material is a first dielectric portion, 1DP, of the electronic device, and further comprising a second dielectric portion, 2DP, wherein:
the 1DP has a proximal end and a distal end;
the 2DP has a proximal end and a distal end; and
the proximal end of the 2DP is disposed proximate the distal end of the 1DP.
12. The electronic device of claim 11 , further comprising an electrical ground plane surface upon which the 1DP is disposed.
13. The electronic device of claim 11 , wherein a height H 2 of the 2DP is greater than a height H 1 of the 1DP.
14. The polymer structure of claim 1 , wherein density of the polymer structure is varied to provide the spatially gradient dielectric constant having endpoints in a range from 20 to greater than 1, measured at 10 GHz, 23° C., and 50% relative humidity.