Lighting device with a built-in antenna

Abstract

A lighting device (such as an LED bulb) has a light source 18, a base part 12, and a top part 62 mounted on the base part 12 such that an interior volume 64 is defined between the base part 12 and the top part 62. Within the interior volume 64 is a two-segment antenna. A first antenna segment 40 extends outwardly from the base part 12 toward the interior volume 64, and a second antenna segment 50 is carried by the top part 62 and mounted to overlap the first antenna segment 40. The first and second antenna segments 40, 50 are physically separate but electrically coupled.

Description

Technical Field

[0001] The present invention relates to lighting devices such as LED lamps incorporating an antenna.

Background Art

[0002] Wireless control of light sources for both indoor and outdoor applications is becoming increasingly popular. Intelligent lighting is spreading, and RF communication is a powerful technology used in particular for this remote management of lamps in home and office environments.

[0003] Instead of controlling the power supply to the lamp, by using wireless control, the light source can be directly controlled by transmitting an RF control signal to the lighting device.

[0004] Glass bulbs such as incandescent bulbs are widely used in the market, but how to wirelessly connect these bulbs is a major issue. For having a good appearance, all of the electronic components are preferably arranged in a compact bottom space surrounded by an electrical connection base.

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the metal material of the base will prevent good transmission and reception of wireless signals, the antenna for wireless connectivity must be placed above the base. In addition, the volume of the base is too small to accommodate an antenna having a sufficient length for commonly used communication standards within the frequency bands of 2.5 GHz or 5 GHz.

[0006] Wire (e.g., loop) antennas have become the most common design because they are easy to fabricate, have little impact on the appearance, and are low cost. However, it still has some disadvantages that make it difficult to achieve the desired performance.

Means for Solving the Problems

[0007] In particular, the antenna has poor radiation performance. The antenna length is limited by the height of the cavity directly below the glass stem of the bulb, and this height is often not sufficient to meet the antenna length requirements for achieving the desired radiation efficiency. Even if some designs use flexible wires to achieve a suitable length, in that case, the position and shape of the antenna are not precisely controlled, which means that the radiation performance is also not clearly defined.

[0008] When a long antenna is attached to the base side of the lamp, since the antenna may come into contact with the stem and be bent or folded, it can often be difficult to always prevent damage to the antenna when assembling the base together with the stem.

[0009] The performance sensitivity and stability may also deteriorate after assembly. The antenna radiation efficiency and pattern are affected, for example, by nearby power cables. Therefore, the performance stability greatly depends on the assembly process, and it is almost impossible to manage this stability during manufacturing.

[0010] The present invention is defined by the claims.

[0011] The concept of the present invention is to provide a lighting device having an antenna formed as two segments. One segment extends from the base of the lighting device, for example, where an electrical connector and circuit mechanism are arranged. The other segment is held by an upper component that fits onto the base. The two segments are physically separated but are arranged side by side, whereby there is an electromagnetic coupling between them. This simplifies assembly by reducing the risk of the long antenna bending or folding, and enabling an antenna longer than would normally fit within the space defined by the upper component, and such a longer antenna can communicate within a lower frequency band that meets a specific communication standard.

[0012] According to an example according to one aspect of the present invention, a lighting device, a light source, a base component, an upper component mounted on the base component, the upper component having an internal volume between the base component and the upper component, comprising, the lighting device being disposed within the internal volume, a first antenna segment having a first length extending outwardly from the base component towards the internal volume, a second antenna segment held by the upper component and mounted so as to partially overlap the first antenna segment, the second antenna segment having a second length parallel to the first length, the first and second antenna segments being physically separated but electrically coupled via non-contact electric and / or magnetic field electrical coupling, the second antenna segment extending outwardly beyond the end of the first antenna segment, further comprising, a lighting device is provided.

[0013] This lighting device incorporates a two-component antenna. The first segment is disposed, for example, within a sealed area defined between the base component and the upper component, whereas the second segment extends further towards the internal volume. Thus, the antenna length can be extended. The second antenna segment is formed as part of the upper component, whereas the first antenna segment is formed as part of the base component, so the physical separation of the antenna segments simplifies assembly. The antenna function is completed by assembling the lighting device. Since the antennas are two non-contact segments rather than a single long antenna, they can be more easily assembled within the lighting device without the risk of bending or folding a single antenna.

[0014] In addition, from one perspective, the second antenna segment increases the antenna length, the electrical coupling can be regarded as a capacitive load, and it also brings another RF band outside the RF band of the first antenna segment alone. Thereby, the design of the two-component antenna enables dual-band operation, and the operating frequency can be easily adjusted by design. From another perspective, the second antenna segment is, for example, an electrically floating radiator. It couples the radio signal supplied to the first antenna segment and excites the target resonance mode. The two segments together determine the lower frequency band of the antenna.

[0015] The first antenna segment is sized, for example, preferably to radiate an RF signal within a first frequency band that includes, for example, 5 GHz. The first segment and the second segment together are sized, preferably, to radiate an RF signal within a second frequency band lower than the first frequency band that includes, for example, 2.4 GHz. 5 GHz may be suitable for 5G Wi-Fi, and 2.4 GHz may be suitable for 2.4G Wi-Fi, Zigbee, Bluetooth. These frequency bands are merely illustrative, and those skilled in the art can also select other values of the frequency bands.

[0016] The electrical coupling is, for example, capacitive coupling.

[0017] Preferably, the coupling coefficient of the capacitive coupling affects the second frequency in an inverse correlation. The capacitive coupling can be regarded as an RF load in the effective antenna formed by the first antenna segment combined with the second antenna segment. Based on simulations and experiments, the higher the coupling coefficient, the smaller the second frequency. Therefore, by adjusting the coupling coefficient, the second frequency band can be finely tuned.

[0018] In a simple implementation form, capacitive coupling is formed by the overlapping length between the first and second antenna segments, as well as the material and spacing therebetween. Therefore, by adjusting the overlapping length, dielectric constant of the material, and / or distance between the first and second antenna segments, the second frequency band can be finely tuned.

[0019] In a detailed embodiment, the first antenna segment may include a base portion close to the base component and an end portion, and the second antenna segment may include a coupling portion and a radiator portion farther from the base portion than the coupling portion. Between the base portion and the radiator portion, the end portion and the coupling portion are adjacent along their longitudinal directions, thereby forming an electrical coupling.

[0020] The radiator portion means that the combination of the first and second antenna segments extends the length of the antenna compared to the first antenna segment alone, and therefore results in a second, lower, frequency band.

[0021] Regarding the overlapping implementation form, the end portion and the coupling portion may be in a horizontally arranged linear structure, or otherwise, the end portion may include a linear structure, and the coupling portion includes a tubular structure surrounding the end portion.

[0022] Therefore, different designs for the overlapping portion of the two antenna segments are possible. In either of these cases, the design can be such that the upper component (with the second antenna segment attached) can be mounted on the base component (accommodating the first antenna segment) while maintaining the same resulting antenna function in any rotational orientation. The horizontally arranged linear structure embodiment is simple to assemble, while the tubular embodiment has the advantage of improved coupling coefficient because the coupling is three-dimensional and can increase the gain of the second frequency band.

[0023] The radiating portion includes, for example, a linear structure or, alternatively, a linear structure having perpendicular end pieces. The optional end pieces provide a top load for the antenna to increase the electrical length of the antenna and / or adjust the input impedance.

[0024] The length of the first antenna segment may approximately correspond to a quarter wavelength of a first frequency, such as a center frequency, within a first (higher) frequency band, and the total length of the base portion and the radiator portion may approximately correspond to a quarter wavelength of a second frequency, such as a center frequency, within a second (lower) frequency band.

[0025] Therefore, the total length of the two antenna segments, except for the area where they are coupled to each other (functioning as capacitive coupling), may be designed based on the desired frequency of the second (lower) frequency band. However, capacitive coupling will also affect the frequency characteristics. The length of the first antenna segment may be designed based on the desired frequency of the first (higher) frequency band. This quarter wavelength is based on the condition that the first antenna segment, as well as the combined first and second antenna segments, are monopole antennas. If they are implemented using another type of antenna structure, those skilled in the art may appropriately design their lengths to meet the length requirements of the other type of antenna structure.

[0026] The lighting device may further include an electrical connector base configured to be connected to an external power source, and the base component fits at least partially into the electrical connector base on the side opposite to the first antenna segment.

[0027] The base component houses an electrical circuit mechanism for the lamp, for example, by arranging the electrical circuit mechanism between the side opposite to the first antenna segment and the base. Therefore, since the electrical circuit mechanism is within the connector base, it is not visible from the outside, giving the lighting device a clean appearance without showing the electrical circuit mechanism.

[0028] Preferably, there is an interface structure between the electric circuit mechanism and the base.

[0029] The lighting device preferably further comprises a lamp enclosure to be sealed by an upper part for accommodating a light source. The sealing is for protecting the light source from environmental dust, moisture, etc. Preferably, in order to protect the light source from oxidation and to dissipate heat, the sealed space may be filled with a rare gas.

[0030] The lamp enclosure has, for example, a bulb shape. The upper part includes, on the side facing the enclosure, for example, a glass stem protruding towards (and into) the lamp enclosure.

[0031] The glass stem functions, for example, as a support for the light source.

[0032] The glass stem may include a plurality of suspension branches for suspending the light source, and the light source includes an LED strip or an LED filament. Therefore, the lighting device may constitute an LED filament bulb.

[0033] This gives the LED filament bulb an appearance comparable to that of a traditional incandescent lamp.

[0034] The upper part may include a dome structure that fits over the base part, and the dome structure is configured to provide an internal volume in which a first antenna segment protrudes inwardly and a second antenna segment is suspended internally.

[0035] Therefore, the internal volume defines the space between the base part and the upper part.

[0036] The dome structure provides an empty space for accommodating the two antenna segments.

[0037] Therefore, the first antenna component is physically separated from the enclosure of the lighting device by the upper component and is disposed within an internal volume formed on the base component. The upper component is, for example, a glass component for closing an internal cavity formed by a lamp enclosure.

[0038] The upper component may include, for example, a concave portion, and a glass stem (overmolded on the second antenna segment) may be suspended within an internal volume defined by the concave portion. The overlap between the first and second antenna segments is within the internal volume.

[0039] The lighting device may further include an insulating overmolded sleeve configured to wrap around at least a portion of the second antenna segment.

[0040] The second antenna segment is, for example, a radiator overmolded within this sleeve, which may be considered a portion of a glass stem that extends inwardly into the internal volume rather than outwardly into the lamp enclosure. Due to the high dielectric constant of the glass, the physical size of the antenna can be reduced. The overmolded glass enclosure also prevents the power cable for the light source from touching the antenna and creates a gap space. Therefore, detuning from the power cable is reduced.

[0041] In one example, the second antenna segment is entirely present within the internal cavity defined by the upper component. Alternatively, the second antenna segment may instead extend upward into a dome structure, for example, into a stem that extends into the enclosure. At this time, the antenna design further overcomes the problem of space limitation in the sealed internal volume between the base component and the upper component. This extended length may be suitable for a desired second frequency band.

[0042] The base component may include an RF transceiver circuit coupled to the first antenna segment and a lighting driver for driving the light source.

[0043] These and other aspects of the invention will become apparent from the embodiments described hereinafter and will be elucidated with reference to the embodiments.

Brief Description of the Drawings

[0044] For a better understanding of the present invention and to more clearly show how the present invention can be carried out, the accompanying drawings are hereinafter referred to, merely by way of example.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0045] The present invention will be described with reference to the drawings.

[0046] The detailed description and specific examples illustrate exemplary embodiments of the apparatus, system, and method, but are for illustrative purposes only and are not intended to limit the scope of the invention. The features, aspects, and advantages of the apparatus, system, and method of the present invention will be better understood from the following description, the appended claims, and the accompanying drawings. It should be understood that these figures are only schematic and are not drawn to scale. Also, the same reference numbers are used throughout these figures to indicate the same or similar parts.

[0047] The present invention provides a lighting device (such as an LED bulb), comprising a light source, a base component, and an upper component mounted on the base component, wherein an internal volume is defined between the base component and the upper component. There is a two-segment antenna within the internal volume. The first antenna segment extends outward from the base component into the internal volume, and the second antenna segment is held by the upper component and is mounted so as to partially overlap the first antenna segment. The first and second antenna segments are physically separated but electrically coupled.

[0048] FIG. 1 shows a well-known lighting device 10 in the form of an LED filament bulb.

[0049] The lighting device 10 includes a base component 12 surrounded by an electrical connector base 13 (shown as a threaded joint in this example). The electrical connector base 13 is for connecting the lighting device to an external power source.

[0050] The base component is at least partially fitted within the electrical connector base 13, which houses the electrical circuit mechanism for the lighting device, and the electrical circuit mechanism is not visible from the outside because it is within the connector base 13.

[0051] The lamp enclosure 14 is provided over the base component 12 and defines a cavity 16 in which the light source 18 (in this example, an LED filament) is received. An electrical connector wire 19 is connected to the end of the LED filament.

[0052] The cavity 16 defined by the lamp enclosure 14 is sealed, among other things, by an upper component 62 over the base 12 (the sealing is more clearly shown in the first drawing in FIG. 6). The lamp enclosure 14 has, in this example, a bulb shape. The upper component 62 includes a glass stem 66 that protrudes into the lamp enclosure 14 on the side facing the inside of the lamp enclosure 14.

[0053] The glass stem 66 functions, for example, as a support for the light source 18. For embodiments of an LED strip or filament, the glass stem has a plurality of hanging branches for hanging the light source.

[0054] The present invention relates in particular to an illumination device incorporating an antenna for enabling wireless communication with an illumination device, for example for remote control of an illumination device that does not require the illumination device to form part of a wired network.

[0055] In a well-known illumination device such as that shown in FIG. 1, an antenna such as a wire loop antenna may be disposed within the space directly below the upper component 62.

[0056] FIG. 2 shows an example of an illumination device according to the present invention.

[0057] The same components are given the same reference numerals as those in FIG. 1.

[0058] Therefore, the illumination device 10 also, in this case as before, includes a base component 12 within the electrical connector base 13 and a lamp enclosure 14 provided over the base component 12 that defines a cavity 16 in which the light source 18 is received.

[0059] In FIG. 2, it can be seen that the upper component 62 on the base 12 defines an internal volume 64 between the base component 12 and the outer peripheral portion of the upper component 62. Here, the term "outer peripheral portion" means the outside of the internal volume 64. The glass stem 66 extends outwardly from the upper part of the upper component 62 and protrudes into the cavity 16 defined by the lamp enclosure 14.

[0060] According to the present invention, the lighting device includes, within the internal volume 64, a first antenna segment 40 having a first length extending outwardly from the base component 12 towards and into the internal volume 64, and a second antenna segment 50 within the internal volume supported (e.g., suspended) by the upper component 62.

[0061] The two antenna segments 40, 50 are arranged side by side (at least within the coupling region between them). The second antenna segment 50 is attached so as to partially overlap the first antenna segment 40, and where they are arranged side by side, they have portions parallel to each other. In this coupling region of the overlap between the two antenna segments, they are physically separated. What this means is that there is no direct electrical conductor connection between them. However, they are electrically coupled via non-contact electric and / or magnetic field electrical coupling. Thus, a change in the electromagnetic field associated with the first antenna segment will include a change in the electromagnetic field associated with the second antenna segment.

[0062] The second antenna segment is, for example, an electrically floating radiator. It couples the radio signal supplied to the first antenna segment and excites a target resonance mode that mainly determines the lower frequency band of the antenna as further described below.

[0063] The second antenna segment 50 extends outwardly beyond the end of the first antenna segment 40. In other words, the second antenna segment extends further towards the cavity defined by the lamp envelope than the first antenna segment. Thus, the antenna length can be extended.

[0064] The second antenna segment 50 is formed as part of the upper component of the lighting device, while the first antenna segment 40 is formed as part of the base component. However, they do not have to be physically, mechanically, or electrically contacted. Therefore, the physical separation of the antenna segments simplifies the assembly. Since the antennas are two non - contacting segments rather than a single long antenna, they can be assembled more easily within the lighting device without the risk of bending or folding.

[0065] Figure 3 shows the antenna structure of Figure 2 in more detail.

[0066] The first antenna segment 40 includes a base portion 42 near the base component 12 having a length L1, and an end portion 44 having a length L2.

[0067] The first antenna segment is, for example, an upright, relatively rigid post extending upward from the base 12. It protrudes into the internal volume 64.

[0068] The second antenna segment 50 includes a coupling portion 52 having a length L2, and a radiator portion 54 further from the base portion than the coupling portion having a length L3.

[0069] Between the base portion 42 and the radiator portion 54, the end portion 44 and the coupling portion 52 are adjacent to each other along their length directions, thereby forming the electrical coupling described above.

[0070] As more clearly shown in FIG. 3, the upper component 62 includes a concave dome structure that fits over the base component 12. The dome structure defines an internal volume 64 in which the first antenna segment 40 projects inwardly and the second antenna segment 50 is suspended internally. The upper component 62 is a glass component for closing the internal cavity 16 formed by the lamp enclosure 14 around its rim, as shown in the first drawing in FIG. 6.

[0071] The glass stem 66 extends upwardly into the internal cavity above the upper component 62. However, within the internal volume 64, there is an insulating overmold sleeve 60 wound around at least a portion of the second antenna segment 50. The second antenna segment is formed, for example, by an overmold process in which a portion of the glass stem 66 that extends inwardly into the internal volume 64 is overmolded onto the second antenna segment.

[0072] Due to the high dielectric constant of the glass, the physical size of the antenna can thereby be reduced. The glass enclosure also prevents the power cable for the light source from touching the antenna and creates a clearance space. Therefore, detuning from the power cable is reduced.

[0073] The radiating portion 54 may simply include a linear structure such as another upright relatively rigid post extending downward from the upper part of the internal volume 64. FIG. 3, instead, shows the second antenna portion having a linear structure with a vertical end piece 56. The end piece provides an upper load for the antenna to increase the electrical length of the antenna and / or adjust the input impedance. More specifically, half of the length of the upper load end piece will be added to the length L3 of the radiator portion 54.

[0074] The use of two antenna segments thus increases the antenna length and also provides another RF band outside the RF band of the first antenna segment alone. This enables the design of a two-component antenna to perform dual-band operation, and the operating frequencies can be easily adjusted by design. The first antenna segment 40 is sized, for example, preferably to radiate RF signals within a first frequency band that includes 5 GHz, and the first segment 40 and the second segment 50 together are sized, preferably, to radiate RF signals within a second frequency band lower than the first frequency band that includes 2.4 GHz.

[0075] Figure 4 shows an electrical model of the antenna function based on the combination of two antenna segments. It includes a first radiator (corresponding to the base portion) of length L1, a capacitive coupling C (corresponding to the coupling between the end portion and the coupling portion), and a radiator (corresponding to the radiator portion) of length L3.

[0076] The first antenna segment 40 is connected to the RF transceiver circuit 70 and creates an electric field for the second antenna segment. The first antenna segment has a length L1 + L2, and this length mainly determines the higher resonance frequency of the antenna.

[0077] The floating second antenna segment 50 couples the radio signal from the first antenna segment (functioning as a primary radiator component) and excites a further target resonance mode that mainly determines the lower resonance frequency of the antenna. The combination of antenna segments also increases the antenna height and enhances the radiation.

[0078] The capacitive coupling defines a coupling coefficient that depends on the load capacitance of the coupling region, which is determined by the length L2 and the distance between the antenna segments.

[0079] The operating frequency of the combined structure is related to the length L1 of the base portion 42, the length L3 of the radiator component 54, and the coupling. From a mathematical perspective, the operating frequency of the combined structure as shown in FIG. 4 can be described as follows: Freq=f(L1,L3,C) L1 and L3 are the segment lengths described above and shown in FIG. 4, and C is the equivalent capacitance between the antenna segments.

[0080] By increasing L1 or L3, the operating frequency can be shifted to a lower band. A smaller value of C increases the operating frequency.

[0081] Based on the known relationships between these design parameters and the desired operating frequency, the design can be implemented using the following steps: (i) Determine the length (L1 + L2) of the first antenna segment, which is the primary radiator. The space is limited within the internal volume 64, which sets the maximum length (L1 + L2) of the first antenna segment. For a dual-band antenna, the value of L1 + L2 is selected based on the length required to implement the higher frequency band. For example, the length may be 1 / 4 of the wavelength of the center frequency within the higher frequency band. If only single-band operation is required, L1 + L2 must be as long as possible (but not more than 1 / 4 of the wavelength of the desired single operating frequency). To obtain the maximum excitation field transmitted to the second antenna segment, the maximum voltage must be at the end of the antenna within the internal volume 64. (ii) Determine the length of the second (overmolded) antenna segment. This is the main radiator for the lower band in the case of a dual-band antenna. The combined initial length (L1 + L3) can generally be determined by 1 / 4 of the wavelength of the lower operating frequency (e.g., the center frequency within the lower frequency band). Since the glass provides a high effective dielectric constant and the coupling effect helps reduce the size, the length will actually be smaller than this quarter wavelength. However, the length may be set to the quarter wavelength, and the operating frequency can be adjusted via the strength of the capacitive coupling (see (iii) below). A smaller coupling results in a higher resonance frequency, which is equivalent to providing a shorter antenna length. (iii) Determine the coupling design. The coupling design will affect the operating frequencies of both the lower and higher bands, and good coupling is an important part for good efficiency. The coupling is preferably at the free end of the first antenna segment. This is because it generates the maximum electric field for coupling to the second antenna segment. At this time, the strong coupling region with its length L2 will not have a significant impact on the lower frequency band and will mainly affect the higher frequency band.

[0082] However, if the coupling is weak, the increased coupling will shift both the higher and lower frequency bands to lower frequencies. Therefore, the coupling capacitance can be used to adjust both operating frequencies.

[0083] For a parallel plate capacitor, C ∝ (ε r . A) / d. Based on this, the load capacitance can be increased by reducing the spacing between the antenna segments in the coupling region and / or increasing the length L2, or increasing the width of the coupling region.

[0084] To reduce the impact of the power cable, the diameter of the glass stem can also be adjusted in the design to ensure the minimum distance between the overmolded second antenna segment and any power cable. As a result, this guarantees a specific performance level. However, a larger diameter also results in a higher, larger relative permittivity ε r as well. The effective permittivity is typically between the permittivity for air (around 1) and the permittivity for glass (around 5.5), which mainly depends on the thickness of the glass. It can be used to reduce the actual antenna length to λ / (4√ε r ).

[0085] The use of the top load as described above increases the effective antenna length, or it can be used to adjust the antenna input impedance. In the case of the T-shaped second antenna segment, when the length of the upper part 56 in FIG. 3 is L4, the electrical length of the second antenna segment is L2 + L3 + L4 / 2.

[0086] The influence of antenna design on electrical performance is modeled. An example is given with L1 = 10 mm, L2 = 10 mm, L3 = 15 mm, and g = 0.5 mm. Here, g is the spacing between the antenna segments within the coupling area. The antenna segments are modeled as being formed by a metal sheet with a width of 1 mm.

[0087] FIG. 5 shows, as plot 80, the frequency response (as reflection attenuation vs. frequency) for a given design of only the first antenna segment, and as plot 82, the frequency response for the combined antenna design when the second antenna segment is added to the design of plot 80. The operating frequency band in plot 80 corresponds to the wavelength related to L1 + L2. The high operating frequency band in plot 82 corresponds to the wavelength related to L1 and C (depending on L2), which is effectively smaller than L1 + L2. Therefore, the frequency band within plot 80 can be considered to be shifted to a higher frequency band by the length of the reduced wavelength compared to the first antenna segment alone.

[0088] The reflection attenuation (S11) has a shallower valley due to the smaller input impedance. This can be adjusted using lumped components. The low operating frequency band of plot 82 corresponds to the wavelength related to L1 + L3 and the coupling coefficient as described above. Therefore, the frequency band is considerably lower than the high operating frequency band. In plot 82, a single antenna ca is used in dual-mode applications such as dual-band operation enabling operation within bands including, for example, 2.4 GHz and bands including 5 GHz, for dual-mode applications such as WiFi or 5G WiFi as well as BLE / Zigbee.

[0089] Figure 6 shows the overmolding assembly process.

[0090] As shown in Figure 6A, the second antenna segment 50 is inserted into the upper part 62 and integrated with the glass stem 66 using a high-temperature firing process within region 90.

[0091] Figure 6B shows one resulting structure with rounded corners, and Figure 6C shows another resulting structure with square corners. The second antenna segment is overmolded by the bottom section of the stem 66 that extends below the upper part of the upper part 62.

[0092] In the above example, the end portion 44 and the coupling portion 52 include a horizontally arranged linear structure. Figure 7 shows that the end portion 44 may instead include a linear structure (e.g., a cylindrical pillar) surrounded by overmolded glass 60. The coupling portion 52 may include a tubular structure concentrically arranged around the end portion 44. This coaxial structure can achieve a larger coupling capacitance using the same distance between the two antenna segments. Figure 7 shows this coupling in a cross-sectional view.

[0093] Therefore, different designs for the overlapping portion of the two antenna segments are possible. However, the design can be such that the upper part 62 (with the second antenna segment attached) can be mounted on the base part 12 (which houses the first antenna segment) while maintaining the same resulting antenna function in any rotational orientation.

[0094] In the above example, the second antenna segment extends downward from the upper part of the upper part into the internal volume 64. Instead, the second antenna segment may extend upward above the dome structure of the upper part and into the stem, which further addresses the problem of lack of space in the internal volume between the base part and the upper part.

[0095] Figure 8 shows the assembly process.

[0096] Figure 8A shows the upper part 62 and the upper part 14, which are already sealed to each other to form the upper unit, together with a separate base unit 12. Also, to enable connection to the lighting driver within the base unit 12, a power supply line for the light source is also provided through the upper part 62. These power cables will be sealed using the same (as in Figure 6) firing step used to overmold the second antenna segment. In the figure, the power cables are omitted.

[0097] In Figure 8B, the upper unit and the base unit are attached together. They are joined to each other in Figure 8C using the interface part 100, which is the bottom cover for the driver. The interface part 100 could be an insulator. In Figure 8D, the end cap is fitted to the interface part 100. The assembly is simplified because any relative orientation of the base part and the upper unit can be used. Note that there are also power lines from the driver to the end cap via the bottom cover, and these power lines are not shown.

[0098] Only one design of a light bulb having a screw connector is shown. The present invention may be applied to any light bulb, or indeed, more generally, to any lighting device, and may be used with any form of electrical connector.

[0099] By considering the drawings, the present disclosure, and the appended claims, variations to the disclosed embodiments can be understood by those skilled in the art and can be carried out when implementing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0100] The mere fact that certain means are recited in mutually different dependent claims does not indicate that a combination of these means cannot be used advantageously.

[0101] It should be noted that when the term "adapted to" is used in a claim or in the body of the specification, the term "adapted to" is intended to be equivalent to the term "configured to".

[0102] No reference signs in the claims should be construed as limiting the scope.

Claims

1. A lighting device comprising: a light source; a base component; an upper component mounted on the base component, the upper component having an internal volume between the base component and the upper component; and a first antenna segment disposed within the internal volume and extending outwardly from the base component towards the internal volume and having a first length; a second antenna segment held by the upper component and attached so as to partially overlap the first antenna segment, the second antenna segment having a second length parallel to the first length, the first and second antenna segments being physically separated but electrically coupled via non-contact electric and / or magnetic field electrical coupling, the second antenna segment extending outwardly beyond an end of the first antenna segment; and a lighting device further comprising.

2. The lighting device according to claim 1, wherein the first antenna segment is sized to radiate an RF signal within a first frequency band, and the first and second antenna segments are sized as a whole to radiate an RF signal within a second frequency band lower than the first frequency band.

3. The lighting device according to claim 1 or 2, wherein the electrical coupling includes capacitive coupling, and preferably, a coupling coefficient of the capacitive coupling affects the second frequency band in an inverse correlation.

4. The lighting device according to any one of claims 1 or 2, wherein the first antenna segment includes a base portion close to the base component and an end portion, and the second antenna segment includes a coupling portion and a radiator portion farther from the base portion than the coupling portion, and between the base portion and the radiator portion, the end portion and the coupling portion are adjacent along their length directions, thereby forming the electrical coupling.

5. The end portion and the coupling portion are in a linearly arranged structure side by side, or the end portion includes a linear structure and the coupling portion includes a tubular structure surrounding the end portion. The lighting device according to claim 4.

6. The radiation portion includes a linear structure, or a linear structure having a vertical end piece. The lighting device according to claim 4.

7. The length of the first antenna segment corresponds to one-quarter wavelength of the center frequency within a first frequency band, The total length of the base portion and the radiating portion corresponds to one-quarter wavelength of the center frequency within a second frequency band, The lighting device according to any one of claims 4 to 6.

8. The lighting device according to any one of claims 1 or 2, further comprising an electrical connector base configured to be connected to an external power source, wherein the base component is at least partially fitted within the electrical connector base on a side opposite to the first antenna segment.

9. The lighting device according to claim 8, further comprising a lamp enclosure to be sealed by the upper component for housing the light source, wherein the upper component includes a glass stem protruding toward the lamp enclosure on a side facing the lamp enclosure.

10. The lighting device according to claim 9, wherein the glass stem includes a plurality of suspension branches for suspending the light source, and the light source includes an LED strip or an LED filament.

11. The lighting device according to claim 9, wherein the upper component includes a dome structure fitted on the base component, and the dome structure is configured to provide the internal volume in which the first antenna segment protrudes inward and the second antenna segment is suspended internally.

12. The lighting device according to claim 11, further comprising an insulating overmold sleeve configured to wrap around at least a portion of the second antenna segment.

13. The lighting device according to claim 11, wherein the second antenna segment extends upward from the dome structure, preferably into the stem.

14. The lighting device according to claim 1 or 2, wherein the base component includes an RF transceiver circuit coupled to the first antenna segment.

15. The lighting device according to claim 1 or 2, wherein the base component includes a lighting driver for driving the light source.

16. The lighting device according to claim 2, wherein the first frequency band includes 5 GHz, and the second frequency band includes 2.4 GHz.

Images