METHOD OF FABRICATING A HEATED PLANAR ANTENNA
A planar antenna that provides a heating function is fabricated by printing a pattern of catalytic ink onto a surface of a web of flexible substrate. The printed pattern of catalytic ink defines an antenna pattern including a radiating element and a ground element. A conductive material is electrolessly plated onto the pattern of catalytic ink by transporting the web of flexible substrate through a reservoir of plating solution to form a corresponding pattern of conductive material. The electrolessly-plated ground element includes a conduction path between a first connection point and a second connection point, wherein the electrolessly-plated ground element is adapted to be connected to a power source to provide a voltage between the first connection point and the second connection point, thereby producing heat by providing a current through the ground element along the conduction path.
1 . A method for fabricating a planar antenna that provides a heating function, comprising:
printing a pattern of catalytic ink onto a surface of a web of flexible substrate, wherein the flexible substrate is non-opaque, and wherein the printed pattern of catalytic ink defines an antenna pattern including:
a radiating element; and
a ground element; and
electrolessly plating a conductive material onto the pattern of catalytic ink by transporting the web of flexible substrate through a reservoir of plating solution to form a pattern of conductive material corresponding to the pattern of catalytic ink;
wherein the electrolessly-plated ground element includes a conduction path between a first connection point and a second connection point; and
wherein the electrolessly-plated ground element is adapted to be connected to a power source to provide a voltage between the first connection point and the second connection point, thereby producing heat by providing a current through the ground element along the conduction path.
2 . The method of claim 1 , wherein the pattern of conductive material corresponding to the radiating element and the ground element is a metal mesh pattern of interconnected microwires.
3 . The method of claim 1 , wherein the conduction path is a serpentine path.
4 . The method of claim 1 , wherein the planar antenna is adapted to detect or transmit a radio frequency signal.
5 . The method of claim 1 , further including connecting the power source to the ground element at the first connection point and the second connection point.
6 . The method of claim 5 , wherein the power source is a DC power source.
7 . The method of claim 5 , wherein the power source is a pulse-width-modulated DC power source or a low-frequency AC power source.
8 . The method of claim 1 , wherein the pattern of conductive material has a resistance of no more than 1 ohm/sq.
9 . The method of claim 1 , wherein the pattern of catalytic ink is printed using a flexographic printing press or a gravure printing press.
10 . The method of claim 1 , wherein an average optical transparency in the pattern of conductive material is at least 50%.
11 . The method of claim 9 , further including incorporating the planar antenna into an automotive window, a building window, or a visor, and wherein the produced heat provides a defrosting or defogging function.
12 . The method of claim 9 , further including incorporating the planar antenna into a solar panel, and wherein the produced heat reduces the buildup of snow or ice on the solar panel.
13 . The method of claim 9 , further including printing a pattern of non-conductive ink onto the surface of the web of flexible substrate in a fill pattern including one or more non-conductive regions, wherein the pattern of non-conductive ink is printed in registration with the pattern of catalytic ink, and wherein the fill pattern is an inverse of the antenna pattern within a defined region of interest;
14 . The method of claim 13 , wherein the pattern of catalytic ink is printed using one or more print modules of a printing press and the pattern of non-conductive ink is printed using one or more additional print modules of the printing press, and wherein the printing press is a flexographic printing press or a gravure printing press.
15 . The method of claim 13 , wherein an average optical transparency in the non-conductive regions is at least 50%, and wherein the average optical transparency of the pattern of conductive material differs from the average optical transparency in the non-conductive regions by no more than 10%.
16 . A method for fabricating a planar antenna that provides a heating function, comprising:
printing a pattern of conductive ink onto a surface of a web of flexible substrate, wherein the flexible substrate is non-opaque, and wherein the printed pattern of conductive ink defines an antenna pattern including:
a radiating element; and
a ground element;
wherein the ground element includes a conduction path between a first connection point and a second connection point; and
wherein the ground element is adapted to be connected to a power source to provide a voltage between the first connection point and the second connection point, thereby producing heat by providing a current through the ground element along the conduction path.
17 . The method of claim 16 , wherein an average optical transparency in the pattern of conductive material is at least 50%.