1. An antenna comprising:
an elongated waveguide having a multi-layer substrate, a major axis, a minor axis, a top surface, a bottom surface, an excitation end, and a load end, the waveguide
propagating radio frequency waves along the major axis;
one or more scattering features disposed on the top surface of or within the waveguide, the scattering features extending from the load end to the excitation end, and operating with the waveguide in a leaky propagation mode to receive energy within a radio frequency band, wherein the waveguide and the scattering features collectively causes frequency-dependent shifts in beam direction; and
a wavelength correction element that provides linear delay to energy incident upon the waveguide to correct for the frequency-dependent shifts in beam direction caused by the waveguide and the scattering features;
wherein the waveguide correction element introduces the delay to energy incident upon the antenna, with the delay increasing from the load end to the excitation end.
2. The antenna of claim 1 wherein the waveguide is a dielectric of a material selected from the group consisting of Si3N4, SiO2, MgF2, and TiO2.
3. The antenna of claim 1 wherein the waveguide is a two dimensional slab and the scattering features are arranged in a two dimensional array.
4. The antenna of claim 1 wherein the wavelength correction element is a correcting wedge-shaped layer disposed above the waveguide.
5. The antenna of claim 4 wherein the correcting wedge introduces delay to energy incident upon the antenna, with the delay increasing from the load end to the excitation end.
6. The antenna of claim 1 wherein a low dielectric constant width gap is disposed between the correcting wedge and the waveguide.
7. The antenna of claim 1 wherein the correction element is a material layer that tapers from a thin section to a thick section.
8. The antenna of claim 7 wherein the thick section is located near the load end.
9. The antenna of claim 1 wherein the correction element is formed of a material having a higher dielectric constant than the waveguide.
10. The antenna of claim 1 wherein a low dielectric constant width layer is disposed between the correction element and the waveguide.
11. The antenna of claim 1 wherein the excitation end is coupled to a common feed and adaptable delay power divider.
12. The antenna of claim 1 further comprising two or more subarrays of leaky mode waveguides wherein the excitation end is coupled to two or more feeds, each feed corresponding to one of the subarrays, and each feed also coupled to a corresponding transmit andor receive module.
13. The antenna of claim 1 further comprising two or more subarrays of leaky mode waveguides with surface features, each such waveguide fed through a respective phase shifter.
14. The antenna of claim 13 wherein the apparatus provides single beam steering.
15. The antenna of claim 1 wherein the scattering features are a slot-fed radiating element.
16. The antenna of claim 1 wherein the multi-layer substrate comprises configurable gaps between selected ones of the layers.
17. The antenna of claim 1 wherein a spacing between selected layers in the multi-layer substrate varies according to a chirp relationship.
18. The antenna of claim 17 wherein each layer is further composed of a low dielectric and a high dielectric sublayer.
19. The antenna of claim 1 wherein the frequency-dependent shifts in beam direction \u03b8 are defined by
cos \u03b8=\u03b2(line)\u03b2\u2212(\u03bbm)s
where \u03b2(line) is a leaky mode propagation constant of the waveguide, \u03b2 the free space propagation constant, m is an order of the beam, s is a spacing between the scattering features, and \u03bb is a wavelength of the beam.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A light emitting solid state lamp comprising:
a light emitting diode (LED) that emits photons having frequencies selected from the group consisting of the ultraviolet, violet and blue portions of the electromagnetic spectrum, an encapsulant, and a header;
said LED comprising a Group III nitride active portion for generating desired frequency photons under the application of current across said LED, wherein said LED is vertically oriented;
said header comprising a reflective cup for supporting said LED and for providing electrical contact to said diode LED and to said active portion;
an ohmic contact to said LED with said ohmic contact being in electrical and direct physical contact with said header;
said encapsulant comprising a phosphor, said encapsulant comprising a plurality of portions wherein said phosphor is present in at least one of said portions of said encapsulant that emits responsive frequencies in the yellow portion of the visible spectrum when excited by frequencies emitted from the group consisting of the ultraviolet, violet and blue portions of the electromagnetic spectrum emitted by said LED, wherein a substantially transparent first portion of said encapsulant partially fills said reflective cup and covers said LED and a second portion of said encapsulant comprises said phosphor and is on said first portion.
2. A solid state lamp according to claim 1 with an output of at least 80 lumens per watt at 20 milliamps drive current.
3. A solid state lamp according to claim 1 with an output of at least 85 lumens per watt at 20 milliamps drive current.
4. A solid state lamp according to claim 1 further comprising:
a conductive silicon carbide substrate comprising a single polytype;
at least one p-type Group III nitride layer on said substrate; and
at least one n-type Group III nitride layer on said substrate in a vertical orientation.
5. A solid state lamp according to claim 4 wherein said ohmic contact is in contact with one of said Group III nitride layers.
6. A solid state lamp according to claim 1 wherein said reflective cup includes a silver coating for maximizing light extraction from said lamp.
7. A solid state lamp according to claim 1 wherein said encapsulant comprises an epoxy resin.
8. A solid state lamp according to claim 1 wherein said phosphor comprises cerium yttrium aluminum garnet.
9. A solid state lamp according to claim 1 comprising at least one p-type Group III nitride layer and an ohmic contact to said p-type layer, said ohmic contact having an average thickness of between about 1 and 250 A.
10. A solid state lamp according to claim 9 wherein said ohmic contact has an average thickness of between about 1 and 10 A.
11. A lamp according to claim 1 wherein said LED has a total dimension between and including any ohmic contacts of no more than 250 \u03bcm.
12. A lamp according to claim 1 wherein said LED has a total dimension between and including any ohmic contacts of no more than 100 \u03bcm.
13. A light emitting solid state lamp comprising:
a light emitting LED that emits photons having frequencies selected from the group consisting of the ultraviolet, violet and blue portions of the electromagnetic spectrum, an encapsulant, and a header;
said LED comprising a conductive substrate for electrical contact and is vertically oriented;
a Group III nitride active portion on said substrate for generating desired frequency photons under the application of current across said LED;
said header comprising a reflective cup for supporting said LED and for providing electrical contact to said LED and to said active portion, said header in direct contact with said LED:
said encapsulant comprising a phosphor, said encapsulant comprising at least a first portion and a second portion wherein said phosphor is present in at least one of said portions of said encapsulant that emits responsive frequencies in the yellow portion of the visible spectrum when excited by frequencies emitted from the group consisting of the ultraviolet, violet and blue portions of the electromagnetic spectrum emitted by said LED, wherein said first portion is substantially transparent, partially fills said reflective cup, and covers said LED, and said second portion comprises said phosphor and is on said first portion.
14. A light emitting solid state lamp according to claim 13 wherein said Group III nitride active portion includes at least one p-type and one n-type layer on said substrate for generating desired frequency photons under the application of current across said LED; and
said p-type layer is positioned adjacent said header.
15. A light emitting solid state lamp according to claim 13 wherein said substrate includes light extraction features.
16. A solid state lamp according to claim 1 with an output of at least 75 lumens per watt at 20 milliamps drive current within a ccx of 0.32-0.37 and a ccy of 0.31-0.39 on the CIE diagram.
17. A light emitting solid state lamp according to claim 13 with an output of at least 75 lumens per watt at 20 milliamps drive current within a ccx of 0.32-0.37 and a ccy of 0.31-0.39 on the CIE diagram.
18. A solid state lamp according to claim 1, wherein said LED is at least 900 \u03bcm\xd7900 \u03bcm, with a quantum efficiency of at least 31% when operating at no more than 350 mA.
19. A solid state lamp according to claim 1, wherein said LED is at least 300 \u03bcm\xd7300 \u03bcm, with a quantum efficiency of at least 44% when operating at no more than 20 mA.
20. A light emitting solid state lamp according to claim 13, wherein said LED is at least 900 \u03bcm\xd7900 \u03bcm, with a quantum efficiency of at least 31% when operating at no more than 350 mA.
21. A light emitting solid state lamp according to claim 13, wherein said LED is at least 300 \u03bcm\xd7300 \u03bcm, with a quantum efficiency of at least 44% when operating at no more than 20 mA.
22. A solid state lamp according to claim 1, wherein the reflective cup comprises a functional shape that maximizes an extraction of light from the LED.
23. A solid state lamp according to claim 1, wherein the reflective cup comprises a frustoconical shape.
24. A solid state lamp according to claim 23, wherein the frustoconical shape comprises the reflective cup including a floor facing a parallel and larger opening and a slanted wall between the floor and the opening.
25. A light emitting solid state lamp according to claim 13, wherein the reflective cup comprises a functional shape that maximizes an extraction of light from the LED.
26. A light emitting solid state lamp according to claim 13, wherein the reflective cup comprises a frustoconical shape.
27. A light emitting solid state lamp according to claim 26, wherein the frustoconical shape comprises the reflective cup including a floor facing a parallel and larger opening and a slanted wall between the floor and the opening.