Lighting device with first and second coupled and inter-movable antennas
Presented is a lighting device ( 100 ) with a light source and a heat dissipating element, comprising: an RF communication circuit ( 102 ); a first antenna ( 105 ) electrically connected to the RF communication circuit and supported by a first portion ( 115 ) of lighting device; and a second antenna ( 125 ) adapted to communicate with external devices and electromagnetically coupled with the first antenna so that the second antenna is adapted to be excited by and to excite the first antenna, the second antenna is adapted to communicate with external devices and being supported by a second portion of the lighting device, wherein the second portion of the lighting device is movable with respect to the first portion of the lighting device.
1. A lighting device with a light source and a heat dissipating element, comprising:
an RF communication circuit;
a first antenna electrically connected to the RF communication circuit and supported by a first portion of the lighting device; and
a second antenna adapted to communicate with external devices and electromagnetically coupled with the first antenna so that the second antenna is adapted to be excited by and to excite the first antenna, the second antenna being supported by a second portion of the lighting device,
wherein the second portion of the lighting device is movable with respect to the first portion of the lighting device.
2. The lighting device of claim 1 , wherein said second portion is displaced from said heat dissipating element.
3. The lighting device of claim 1 , wherein the second portion of the lighting device is movable with respect to the first portion of the lighting device so as to alter the electromagnetic coupling between the first and second antennas.
4. The lighting device of claim 1 , wherein the second portion of the lighting device is movable with respect to the first portion of the lighting device so as to alter the radiation pattern of the second antenna with respect to the first portion.
5. The lighting device of claim 1 , wherein the first portion of the lighting device comprises a body part situated in a housing of the lighting device, wherein said housing comprises said heat dissipating element and
wherein the second portion of the lighting device comprises a cap part mounted above the housing of the lighting device.
6. The lighting device of claim 4 , wherein the cap part comprises an optically transmissive part through which light from the light source can pass, and the second antenna is at the periphery of the optically transmissive part.
7. The lighting device of claim 5 , wherein the body part comprises:
a cup side wall comprising a heat sink material, which constitutes at least a first part of the heat dissipating element, wherein a top opening of the cup is for engaging the cap part;
a support plate placed at the middle of the cup for supporting said light source, and comprising a heat spreader material, which constitutes at least a second part of the heat dissipating element, thermally coupled to said light source and said cup side wall; and
a PCB above said support plate, comprising a trace printed thereon as said first antenna.
8. The lighting device of claim 6 , wherein the light source is oriented facing said cap part and adapted to generate light along an optical axis, and wherein the second antenna is supported by the cap part so as to be positioned above a virtual plane drawn orthogonal to the optical axis and through the first antenna.
9. The lighting device of claim 1 , wherein said second portion of the lighting device is rotatable with respect to said first portion of the lighting device so as to adjust the angle between said second antenna and said first antenna.
10. The lighting device of claim 1 , wherein said second portion of the lighting device is displaceable upward and downward with respect to said first portion of the lighting device so as to adjust the vertical distance between said second antenna and said first antenna.
11. The lighting device of claim 1 , wherein said second portion of the lighting device comprises recesses placed at different radial locations for receiving said second antenna such that the radial distance between the second antenna and the first antenna is adjustable.
12. The lighting device of claim 1 , wherein the first antenna is one of: an IFA antenna; a PIFA antenna; a Yagi antenna; and a loop antenna.
13. The lighting device of claim 1 , wherein the second antenna comprises a metallic component having an extension no larger than ½ of the wavelength of RF control signals communicated by the first antenna.
14. The lighting device of claim 9 , wherein the second portion of the lighting device comprises dielectric materials and the extension of the metallic component of the second antenna is shorter than ½ of the wavelength of the RF control signals.
15. A lamp comprising a lighting device according to claim 1 .