Antenna device that can be integrated in an electronic instrument housing

Abstract

One aspect of the invention relates to an antenna device designed to be integrated in a housing (2), particularly in the housing (2) of a wearable electronic device (1), wherein at least a portion of the housing is conductive, the device (3) comprising: a first antenna portion (4A) designed to be connected by a first connector (8A) to a functional module (7) on a circuit board (10) located inside the housing (2); and a second antenna portion (4B) consisting of a ground plane including the at least conductive portion of the housing (2), wherein a second connector (8B) in the first antenna portion (4A) is connected to the ground plane via an electronic module (4C) for tuning a resonant frequency and increasing the efficiency of the antenna device (3) according to the angular position of the device (3).

Description

Technical Field

[0001] This invention relates to the field of antennas embedded in electronic instruments such as watches, wherein the housing is small or includes compartments with small volumes for housing the antenna device. Background Technology

[0002] Existing antenna devices are typically integrated into metal housings within electronic instruments to receive GNSS signals for use in navigation or guidance systems implemented within the instruments.

[0003] However, one of the main problems with this configuration is that mechanical characteristics, such as the shape and arrangement of the metal housing or the presence of other metal components or parts within the housing, have a significant impact on the performance of the antenna device. In fact, the performance is drastically altered compared to when the antenna device is not integrated into such a metal housing and thus encapsulated. In reality, the mechanical environment of this antenna device has a significant impact on its performance, particularly reducing its performance in tuning, gain, and radiation.

[0004] In general, the prior art discloses various methods for designing antenna devices, especially for designing miniature antenna devices, and particularly for designing antenna devices with transmit / receive characteristics in the frequency band for GNSS signals.

[0005] However, there is no known satisfactory solution for optimizing the performance of such antenna devices designed to be encapsulated in a metal housing.

[0006] In these situations, it is clearly necessary to find alternative solutions to the existing technologies. Summary of the Invention

[0007] The purpose of this invention is to improve the performance of an antenna device arranged in a small housing, the small housing comprising at least one metal component and / or integrating at least one metal element in its compartment.

[0008] The present invention also aims to ensure or guarantee optimal reception of electromagnetic signals by the antenna device, regardless of the orientation or location of the device relative to the source emitting the electromagnetic signals.

[0009] This invention relates to an antenna device designed to be integrated into a housing, particularly into the housing of a wearable electronic device, wherein at least a portion of the housing is conductive, and the device comprises: - The first antenna section is designed to be connected by a first connector to a functional module on a circuit board located inside the housing; and - The second antenna section consists of a ground plane, which includes at least a conductive portion of the housing. A second connector in the first antenna section is connected to the ground plane via an electronic module for tuning the resonant frequency and increasing the efficiency of the antenna device according to the angular position of the device.

[0010] Another aspect of the present invention relates to: - The electronic module includes circuitry that can be dynamically configured according to the angular position of the antenna device and a module for detecting changes in the angular position of the antenna device; The circuit comprises two components: a coil and a capacitor; - The circuit includes three switches provided to configure the circuit in a first configuration mode and a second configuration mode, in which the coil and the capacitor are arranged in series and in parallel, respectively. - In the first configuration mode and the second configuration mode, the inductance value of the coil and the capacitance value of the capacitor are selected to satisfy the following equation: L series × C series = L parallel × C parallel .

[0011] - The detection module includes at least one angular position sensor and a processing unit; - The antenna device is configured to receive one or more GNSS signals transmitted by a GNSS source in a given frequency band; - The antenna device is configured to radiate in a frequency band corresponding to wavelength λ, and the shape and length of the first antenna portion are configured such that the first antenna portion has an electrical measurement length λ / 4; - The frequency band is included between 1559 MHz and 1610 MHz.

[0012] In another aspect, the present invention relates to an electronic device worn by a wearer, the electronic device comprising a housing having at least one conductive portion configured to contact a portion of the wearer's body, the housing holding an antenna device according to any one of the preceding claims and a circuit board comprising: -A functional module, which is electrically connected to a first connector on the first antenna section; and - An electronic module for tuning the resonant frequency and improving the efficiency of the antenna device according to the angular position of the antenna device, the electronic module being electrically connected to the second connector and the ground plane on the antenna device.

[0013] Advantageously, the ground plane includes: a first portion contained on the circuit board; and a second portion including at least a conductive portion of the housing.

[0014] Specifically, the functional module is a GNSS signal receiver module that includes radio frequency circuitry.

[0015] Advantageously, electronic instruments are watches, especially wristwatches. Attached Figure Description

[0016] Other features and advantages of the invention will become clearer from the following description of specific embodiments of the invention, provided only as illustrative and non-limiting examples, and from the accompanying drawings, wherein: - Figure 1 This is a schematic diagram of the housing of an electronic instrument including an antenna device according to an embodiment of the present invention, in which the electronic instrument is a watch; Figure 2A This is a circuit design plan view according to an embodiment of the present invention, wherein components such as coils and capacitors can be configured in series or parallel arrangement in the circuit; Figure 2B This is a circuit design plan view according to an embodiment of the present invention, wherein the coil and the capacitor are arranged in series in the circuit; - Figure 2C This is a circuit design plan view according to an embodiment of the present invention, wherein the coil and capacitor are configured in parallel in the circuit; Figure 3 This is a radiation pattern of an antenna device integrated into the housing of an electronic instrument (in this example, a watch case) when the housing is arranged in a horizontal position, according to an embodiment of the present invention; and Figure 4 This is a radiation pattern of an antenna device integrated into the housing of an electronic instrument (in this example, a watch case) when the housing is arranged in a vertical position, according to an embodiment of the present invention. Detailed Implementation

[0017] Figures 1 to 4 The invention relates to an antenna device 3, particularly a beam or directional antenna device, which can radiate or receive more power in a specific direction. This antenna device 3 is designed to be integrated into the housing 2 of the electronic instrument 1.

[0018] This electronic device 1 is a communication object having a housing 2 that is smaller than the wavelength used for communication. Typically, the housing 2 of the object involved in this invention has a size of about a few centimeters.

[0019] In one potential application, the antenna device 3 is integrated into a navigation or guidance system implemented in the electronic instrument 1 by being encapsulated in a housing 2, at least a portion of which is conductive. Such an electronic instrument 1 is preferably a watch, but in other alternatives, the instrument 1 can be a portable or wearable object, such as a smartphone, a band such as a ring, a household item, etc., in a non-limiting and non-exhaustive manner. However, it should be understood that other applications are contemplated for this invention, provided that the small antenna device 3 is encapsulated in an equally small housing.

[0020] The watch 1 is, for example, a traditional wristwatch, which, in addition to the antenna device 3, includes a housing 2, a wristband attached to the housing 2, a crystal (below which is a display device enclosed in the housing 2), and a control mechanism. In this particular case, the display device includes an analog display with two or three hands that move relative to the dial, specifically to allow for conventional time resolution, and this display device can be supplemented by a digital display using LCD or OLED display technology.

[0021] In the watch 1, the housing 2 includes a circuit board 10 with multiple compartments for housing various electronic and electrical components of the watch 1, including elements of the antenna device 3. These electronic and electrical components specifically include a motor with a shaft for driving the hands, a first conductive portion 9A on the ground plane of the antenna device 3, and electrical power specifically for powering the display device, the functional module 7, and the electronic module 4C included in the antenna device 3. This power source can consist of a conventional battery or battery pack, a rechargeable battery, or any other suitable electrical energy source.

[0022] In the context of a watch 1 implementing a navigation or guidance system, the antenna device 3 is configured to receive one or more GNSS signals transmitted by a GNSS source in a frequency band used by a constellation of Global Positioning Satellites. In other words, the antenna device is configured to receive satellite positioning and navigation signals, such as GPS signals from the US NAVSTAR satellite positioning system or other positioning signals from similar systems, such as the Chinese BEIDOU system, the Russian GLONASS system, or the European GALILEO satellite positioning and navigation system.

[0023] In these cases, the antenna device 3 is therefore configured to receive signals belonging to at least one frequency band included between 1559 MHz and 1610 MHz. More specifically, the antenna device is configured to receive signals included in at least one of the following frequency bands: -1559 to 1610 MHz, covering frequencies L1, E1, and B1; -1215 to 1300 MHz, covering frequencies L2, E6, B3, and L6; -1164 to 1215 MHz, covering frequencies L5, E5, B2, and L3.

[0024] In the embodiments described herein, it is assumed that antenna device 3 is configured to receive a signal having a frequency L1 of approximately 1575.42 MHz.

[0025] As is known in the prior art, metal components included in the housing 2, or even the metal portion of the housing 2 that typically encapsulates an antenna device, can form a shield that degrades the performance of such a device. In this context, the present invention proposes to form an antenna device 3 comprising two parts 4A and 4B: a first part 4A having an IFA (“inverted-F antenna”) structure adapted to be connected to a functional module 7 included on a circuit board 10; and a second part 4B consisting of ground planes 9A and 9B comprising at least conductive portions of the housing 2.

[0026] Therefore, refer to Figure 1 The first antenna section 4A consists of segments or strands with a curved shape. The segment is a conductive element that serves as a radiating element of the antenna device 3, and it is oriented parallel to the plane of the opening 13 formed in the surface of the housing 2, which is designed to be closed by the glass of the watch 1.

[0027] The segment has a length equal to a fraction of the incident electromagnetic wavelength to be received, and it is converted into an electrical signal received by functional module 7. More specifically, the segment is configured to radiate in a frequency band corresponding to wavelength λ, and its shape and length are configured such that it has an electrical length of λ / 4. In this embodiment, antenna device 3 radiates in response to the received electromagnetic wave with a frequency L1 of 1575.42 MHz. In this configuration, the length of the segment is included between 44 mm and 46 mm, and preferably 45.7 mm.

[0028] It should be noted that in the case 2 of the watch 1, the first antenna portion 4A (particularly this segment) is arranged above the dial, for example in the bezel or even in the flange of the watch 1, oriented parallel to the plane including the opening marked 13 in the figure of reference numeral 13 of the case 2. In this context, the bezel and the flange are made of a non-conductive (dielectric) material such as plastic, thereby enabling the antenna device 3 to be electrically isolated from the case 2.

[0029] The first antenna section 4A includes a first connector 8A, which is substantially included in the middle of the section, i.e., in the portion 11C located between the two ends 11A and 11B of the section. The first connector 8A, also referred to as an "antenna foot" or "antenna feed," is configured to connect to a functional module 7, which will be positioned on a circuit board 10 arranged in the housing 2.

[0030] Functional module 7 is a GNSS signal receiver module including radio frequency circuitry. In this embodiment, the functional module is configured to receive specific L1 type satellite radio signals associated with carrier frequency and bandwidth. Functional module 7 is powered by an electrical power supply.

[0031] The first antenna section 4A also includes a second connector 8B, which is included at one of the two ends 11A, 11B of the section. The second connector 8B, also referred to as an "antenna load", is configured to be connected to the ground planes 9A, 9B via an electronic module 4C for tuning the resonant frequency and improving the efficiency of the antenna device 3.

[0032] As described above, the electronic module 4C of the antenna device 3 is arranged on the circuit board 10. This module 4C consists of a circuit 5A and a module 5B, the circuit being dynamically configured according to the angular position of the antenna device 3, and the module being used to detect changes in the angular position of the device 3.

[0033] In module 4C, the detection module 5B includes at least one angular position sensor 6A, which comprises an inertial unit and / or a gyroscope sensor in a non-limiting and non-exhaustive manner. The detection module 5B also includes a processing unit 6B, such as a microcontroller. The processing unit 6B is designed to control / drive the configuration of the circuitry 5A based on measurements of the angular position of the housing 2, and thus control / drive the configuration of the antenna device 3, which can be received from the sensor 6A.

[0034] refer to Figure 1 and 2A The circuit 5A includes a first connection point P and a second connection point M electrically connected to the second connector 8B, the second connection point being connected to a first portion of the ground plane 9A on the antenna device 3 defined on the circuit board 10.

[0035] In this configuration, the circuit 5A is configured to act on the load of the first antenna section 4A but not on its power supply. In these cases, the circuit 5A includes two components: a coil L and a capacitor C. The circuit also includes three switches S1, S2, and S3, whose opening and closing are controlled by the processing unit 6B to set / configure the circuit 5A in the following ways: -like Figure 2BIn the first configuration shown, the coil L and capacitor C are connected in series by closing switch S2 and opening switches S1 and S3; and -like Figure 2C In the second configuration shown, the coil L and capacitor C are arranged in parallel by closing switches S1 and S3 and opening switch S2.

[0036] By generating the displacement of the minimum and maximum values ​​of the radiation of the first antenna section 4A, that is, by changing the gain of the antenna device 3 in the spatial direction according to the different angular positions of the housing 2 and therefore according to the different angular positions of the antenna device 3, the two configuration modes of the circuit 5A act differently on the load of the first antenna section 4A.

[0037] For example, when housing 2 is in the "horizontal" position, the upper surface of the first antenna section 4A is arranged to face or substantially face the GNSS source. In these cases, circuitry 5A is subsequently configured by processing unit 6B in a first configuration mode. In the first mode, as... Figure 3 The radiation pattern of the antenna device 3 shown typically defines the spatial power distribution of the antenna device 3. This radiation pattern describes the direction along which the antenna device 3 radiates at maximum power, which in this case is the direction of the Oz axis.

[0038] exist Figure 3 From the radiation diagram, it can be seen that: - The maximum gain is -10.77 dBi; - The opening at 3 dB is 157.6 degrees.

[0039] In another example, when housing 2 moves from a horizontal position to a new position (in this case, a vertical position), electronic module 4C then detects this change in the angular position of housing 2. In these cases, electronic module 4C then configures circuit 5A in a second configuration mode. In this context, as... Figure 4 The radiation diagram of the antenna device 3 shown describes the direction along which the antenna device 3 radiates at maximum power, in this case, the direction included between the Oy and Oz axes.

[0040] exist Figure 4 From the radiation diagram, it can be seen that: - The maximum gain is -10.65 dBi; - The opening at 3 dB is 147.2 degrees.

[0041] It should be noted that in these radiation diagrams, the case 2 of watch 1 is attached to the wearer's wrist 12. Furthermore, it should be noted that spherical coordinate angles (θ, φ) are used, such as... Figure 3 and 4As shown. Angle "θ" is labeled relative to the Oz axis, and angle "φ" is located in the xOy plane and labeled relative to the Ox axis.

[0042] In circuit 5A, when capacitor C and coil L are used in the first and second configuration modes of circuit 5A, the capacitance value C of capacitor C is selected. series C parallel And the inductance value L of coil L series L parallel This satisfies the following equation: L series × C series = L parallel × C parallel in: -L series and C series This represents the inductance and capacitance values ​​of the coil L and capacitor C in the first configuration of circuit 5A; -L parallel and C parallel This indicates the inductance and capacitance values ​​of the coil L and capacitor C in the second configuration of circuit 5A.

[0043] Choosing or selecting these inductor and capacitor values ​​from this equation helps ensure that the load resonates at the correct frequency. It also helps increase the efficiency of the antenna assembly, such as... Figure 3 and 4 The radiation diagram shown is illustrated in the image.

[0044] As previously described, the antenna assembly 3 also includes a second antenna portion 4B composed of ground planes 9A and 9B. These ground planes 9A and 9B are enlarged ground planes because they are composed of first and second portions 9A and 9B, with the second portion 9B including at least a conductive portion of the housing 2. This ground plane is connected to a second connector 8B on the first antenna portion 4A via an electronic module 4C.

[0045] In this ground plane, the first portion 9A is connected to the second portion 9B via a conductor trace. The circuit board 10 can actually include such a conductor trace on the lower surface of the board 10. Therefore, this trace is electrically connected to the first portion 9A of the ground plane. This conductor trace can be arranged around the periphery of the circuit board 10, and specifically located in the mechanical contact area between the circuit board 10 and the at least conductive portion of the housing 2, for example, via a shoulder on the body of the at least conductive portion. Preferably, the conductor trace can extend substantially around the entire periphery of the circuit board 10, although the conductor trace can be interrupted at one or more points around the periphery. Positioning the trace around almost the entire periphery of the circuit board 10 has the advantage of improving the quality of electrical contact with the conductive portion of the housing 2. It should be understood that this configuration maximizes the surface area of ​​the ground plane by extending the ground plane to the conductive portion of the housing 2. Furthermore, this enlargement of the ground plane on the antenna device improves the detection sensitivity of the antenna device.

[0046] It should be noted that the conductive component is made of a conductive material, preferably a metal (e.g., steel, titanium, or aluminum), or a base material covered with a conductive outer layer. This conductive portion preferably includes an area or portion of the housing 2 that is designed to contact a part 12 of the wearer's / user's body (e.g., their wrist), and this area or portion may be, for example, the back of the housing 2.

[0047] Using the device according to the invention, the antenna device 3 can be integrated into the housing 2 of the watch 1, while using a portion of the metal housing 2 to optimize the performance of the antenna device 3. Furthermore, as already seen, the electronic module 4C included in the antenna device 3 enables the integration of beamforming and beam control technologies into the functionality of the device 3, and also improves the performance of the antenna device 3, particularly in terms of gain, tuning, efficiency, and radiation.

[0048] Therefore, the watch 1 equipped with this antenna device 3 and worn on the wearer's wrist 12 can optimally receive GNSS signals, regardless of its position or orientation relative to the receiving area for these GNSS signals, which is caused by the movement of the wearer's wrist when the wearer is engaged in physical or sporting activities (hiking, cycling, etc.).

[0049] This invention is specifically designed for the field of watchmaking, but it can also be used in other fields.

[0050] It should be further noted that the present invention is not limited to the above examples, and many variations can be obtained by those skilled in the art.

[0051] List of terms 1. Electronic instruments 2. Shell 3. Antenna device 4A. First antenna section 4B. Second Skyline Section 4C. Electronic Module 5A. Dynamically configurable circuit 5B. Angular position change detection module 6A. Angular position sensor 6B. Processing Unit 7. Functional Modules 8A. First connector in the first antenna section 8B. Second connector in the first antenna section 9A. The first part of the ground plane on the antenna assembly 9B. The second part of the grounding plane, including the conductive portion of the housing. 10. Circuit board 11A. The first end of the first antenna section 11B. The second end of the first antenna section 11C. The portion positioned approximately equidistant from the end of the segment. 12. Body parts of the wearer, such as their wrists. 13. Openings in the surface of the shell.

Claims

1. An antenna device (3) designed to be integrated in a housing (2), particularly in a housing (2) of a wearable electronic device (1), wherein at least a portion of the housing is conductive, the device (3) comprising: - The first antenna section (4A) is designed to be connected by a first connector (8A) to a functional module (7) on a circuit board (10) located inside the housing (2); as well as - The second antenna section (4B) consists of a ground plane including at least the conductive portion of the housing (2), and the second connector (8B) in the first antenna section (4A) is connected to the ground plane via an electronic module (4C) for tuning the resonant frequency according to the angular position of the device (3) and increasing the efficiency of the antenna device (3).

2. The antenna device (3) according to the preceding claim, wherein, The electronic module (4C) includes a circuit (5A) that can be dynamically configured according to the angular position of the antenna device (3) and a module (5B) for detecting changes in the angular position of the antenna device (3).

3. The antenna device (3) according to the preceding claim, wherein, The circuit (5A) includes two components: a coil (L) and a capacitor (C).

4. The antenna device (3) according to any one of claims 2 and 3, wherein, The circuit (5A) includes three switches (S1, S2, S3) configured to configure the circuit (5A) in a first configuration mode and a second configuration mode, in which the coil (L) and the capacitor (C) are arranged in series and in parallel, respectively.

5. The antenna device (3) according to the preceding claim, wherein, In both the first and second configuration modes, the inductance value (L) of the coil (L) series L parallel ) and the capacitance value (C) of the capacitor (C) series C parallel ) is selected to satisfy the following equation: L series × C series = L parallel × C parallel 。 6. The antenna device (3) according to any one of the preceding claims, wherein, The detection module (5B) includes at least one angular position sensor (6A) and a processing unit (6B).

7. The antenna device (3) according to any one of the preceding claims, wherein, The antenna device is configured to receive one or more GNSS signals transmitted by a GNSS source in a given frequency band.

8. The antenna device (3) according to any one of the preceding claims, wherein, The antenna device is configured to radiate in a frequency band corresponding to wavelength λ, and the shape and length of the first antenna portion (4A) are configured such that the first antenna portion (4A) has an electrical measurement length λ / 4.

9. The antenna device (3) according to the preceding claim, wherein, The frequency band is included between 1559 MHz and 1610 MHz.

10. An electronic device (1) worn by a wearer, the electronic device comprising a housing (2) having at least one conductive portion configured to contact a part (12) of the wearer's body, the housing (2) holding an antenna device (3) according to any one of the preceding claims and a circuit board (10), the circuit board comprising: -The functional module (7) is electrically connected to the first connector (8A) on the first antenna portion (4A); as well as - The electronic module (4C) is used to tune the resonant frequency and increase the efficiency of the antenna device (3) according to the angular position of the antenna device (3). The electronic module (4C) is electrically connected to the second connector (8B) and the ground plane on the antenna device (3).

11. The electronic instrument (1) according to the preceding claim, wherein, The ground plane includes: a first portion (9A) contained on the circuit board (10); and a second portion (9B) including at least a conductive portion of the housing (2).

12. The electronic instrument (1) according to the preceding claim, wherein, The functional module (7) is a GNSS signal receiver module that includes radio frequency circuitry.

13. The electronic instrument (1) according to any one of claims 10 to 12, wherein, The electronic instrument in question is a watch, particularly a wristwatch.

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