Radio Frequency (RF) and Infrared (IR) Transparent Resistive Heaters

Abstract

Resistive heating systems are described that have alternating, concentric positive and negative electric leads coated by a thin resistive heating layer. The resistive heating system, especially when the coating is a CNT coating, exhibits excellent transmittance in the L, S, C, X, and/or Ku bands. The resistive heating system is well-suited for a radome, and the invention includes a transmitter system and/or receiver system, especially for radio or infrared transmissions. The invention also provides a polarizable resistive heating system having a comb-like structure of alternated or interdigitated positive and negative leads.

Description

Claims

1. A resistive heater system, comprising: a substrate; a resistive heating element disposed on the substrate comprising a plurality of alternating, concentric positive and negative electric leads coated by a resistive heating layer.

2. The radome comprising the resistive heater system of claim 1.

3. The resistive heater system of claim 1 comprising a radio or infrared transmitter or receiver or transceiver at least partly housed within the resistive heater system.

4. The resistive heater system of claim 1 wherein the resistive heating element comprises a CNT resistive heating layer.

5. The resistive heater system of claim 4 wherein the CNT resistive heating layer has a thickness in the range of 15 to 200 nm and a resistance of 100 to 400 ohm/sq.

6. The resistive heater system of claim 1 wherein the resistive heating element is at least 70% transparent in the wavelength range of one or any combination of 1 to 4 GHz, or 1 to 10 GHz, or 2 to 18 GHz, or from 4 to 16 GHz, or in the L Band, S Band, C Band, X Band, and/or Ku Band.

7. The resistive heater system of claim 5 wherein the resistive heating element is at least 70% transparent in the wavelength range of one or any combination of 1 to 4 GHz, or 1 to 10 GHz, or 2 to 18 GHz, or from 4 to 16 GHz, or in the L Band, S Band, C Band, X Band, and/or Ku Band.

8. The resistive heater system of claim 7 wherein resistive heater system maintains at least 70% transparency while constant current is passed through the system to generate heat sufficient to melt a 3 mm thick ice layer from the surface of the system in an ambient atmosphere maintained at -20° C.

9. The resistive heater system of claim 6 wherein resistive heater system maintains at least 80% transparency in the wavelength range of 4 to 16 GHz while constant current is passed through the system to generate heat sufficient to melt a 3 mm thick ice layer from the surface of the system in an ambient atmosphere maintained at -20° C.

10. The resistive heater system of claim 1 comprising at least 3 concentric positive leads alternating with at least 3 concentric negative leads.

11. The resistive heater system of claim 10 wherein the at least 3 concentric positive leads share a common first lead and wherein the at least 3 concentric negative leads share a common second lead.

12. A resistive heater system comprising: a substrate; a resistive heating element disposed on the substrate comprising alternating positive and negative electric leads coated by a CNT resistive heating layer having a thickness in the range of 15 to 200 nm, and a resistance of 100 to 400 ohm/sq.

13. The resistive heater system of claim 12 wherein the CNT resistive heating layer has a thickness in the range of 15 to 100 nm.

14. The resistive heater system of claim 12 wherein the resistive heating element is at least 70% transparent in the wavelength range of one or any combination of 1 to 4 GHz, or 1 to 10 GHz, or 2 to 18 GHz, or from 4 to 16 GHz, or in the L Band, S Band, C Band, X Band, and/or Ku Band.

15. The resistive heater system of claim 14 wherein resistive heater system maintains at least 70% transparency while constant current is passed through the system to generate heat sufficient to melt a 3 mm thick ice layer from the surface of the system in an ambient atmosphere maintained at -20° C.

16. The resistive heater system of claim 14 wherein resistive heater system maintains at least 70% transparency while constant current is passed through the system to generate heat sufficient to melt a 3 mm thick ice layer from the surface of the system in an ambient atmosphere maintained at -20° C.

17. The resistive heater system of claim 14 wherein resistive heater system maintains at least 70% transparency while constant current is passed through the system to generate heat sufficient to melt a 3 mm thick ice layer from the surface of the system in an ambient atmosphere maintained at -20° C.

18. The resistive heater system of claim 12 comprising at least 3 positive leads that share a common first lead and at least 3 negative leads that share a common second lead.

19. A polarizable resistive heater system, comprising: a substrate; a resistive heating element disposed on the substrate comprising a comb-like structure of positive and negative electric leads coated by a resistive heating layer; wherein the comb-like structure comprises a series of at least 3 positive electric leads alternated (or interdigitated) with at least 3 negative electric leads.

20. The polarizable resistive heater system of claim 19 wherein the positive leads share a common first lead and the negative leads share a common second lead.