Metal ring antenna structure suitable for wearable device

Abstract

The utility model relates to a metal ring antenna structure suitable for wearable equipment, which comprises a PCB mainboard, a metal ring is arranged on the outer ring of the PCB mainboard, a clearance groove with a certain width is reserved between the metal ring and the PCB mainboard, an antenna feed end and an antenna grounding pin are arranged on the metal ring, a first metal elastic sheet and a second metal elastic sheet are arranged on the PCB mainboard, and the first metal elastic sheet and the second metal elastic sheet are arranged on the PCB mainboard. A leading-out pin of an antenna feed end on the metal ring is connected into the PCB mainboard by being connected with a first metal elastic piece, an antenna grounding pin on the metal ring is connected with a second metal elastic piece, and the second metal elastic piece is connected with a single-pole four-throw switch chip on the PCB mainboard through a corresponding circuit and used for switching of different states of the antenna. The working frequency band of the antenna is expanded, and the performance is improved. The antenna provided by the utility model is simple in structure and small in size, and can be very suitably applied to wearable equipment to realize a voice communication function, and the return loss and efficiency parameters of the antenna completely meet the application requirements of the wearable equipment.

Description

Technical Field

[0001] The utility model relates to the field of radio frequency and wireless communication, and in particular to a metal ring antenna structure suitable for wearable devices. Background Art

[0002] Smart wearable devices are now more and more widely used in people's lives. There are more and more functional applications. Accurate positioning and fast data transmission are required, which require a large number of antennas in the device and very high antenna performance parameters. Due to the requirements for a strong and beautiful appearance, more and more metal is used in the device shell, which significantly increases the difficulty of antenna design, especially the increasing investment in the design and development of 4GLTE / 5G multi-band antennas. Especially in metal wearable devices, which are small in size, it is extremely challenging to design an antenna that includes the low-frequency band of 699MHz to 960MHz. Utility Model Content

[0003] The purpose of the utility model is to overcome the problems existing in the prior art and provide a metal ring antenna structure suitable for wearable devices as a 4G / 5G antenna solution for metal ring wearable devices.

[0004] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0005] A metal ring antenna structure suitable for wearable devices comprises a PCB mainboard, wherein the outer ring of the PCB mainboard is provided with a metal ring, a clearance groove of a certain width is left between the metal ring and the PCB mainboard, an antenna feed end and an antenna grounding pin are provided on the metal ring, a first metal shrapnel and a second metal shrapnel are provided on the PCB mainboard, a lead-out pin of the antenna feed end on the metal ring is connected to the PCB mainboard by connecting the first metal shrapnel, the antenna grounding pin on the metal ring is connected to the second metal shrapnel, and the second metal shrapnel is connected to a single-pole four-throw switch chip on the PCB mainboard through a corresponding circuit, so as to switch between different states of the antenna, so as to expand the working frequency band of the antenna and improve the performance.

[0006] Furthermore, the switch chip includes an access point and 1st to 4th port circuits, wherein the access point is connected to the second metal spring, the 1st port is connected to the ground through an inductor, the 2nd port is connected to the ground in series through a capacitor and an inductor, the 3rd port is connected to the ground through a capacitor, and the 4th port is an unloaded position. The switch chip is selected on the corresponding port circuit according to the high and low levels to realize the switching of different states of the antenna.

[0007] Furthermore, the clearance slot extending clockwise from the antenna feed end to the antenna ground pin is a first clearance slot, and its length and width control the low frequency of the antenna. The clearance slot extending counterclockwise from the antenna feed end to the antenna ground pin is a second clearance slot, and its length and width control the high frequency of the antenna.

[0008] Furthermore, the antenna structure also includes a display screen and a battery, wherein the display area of ​​the display screen is smaller than or equal to the copper area of ​​the PCB mainboard, and the battery area is smaller than or equal to the copper area of ​​the PCB mainboard.

[0009] Furthermore, the metal ring serves as a part of the structure of the corresponding wearable device housing to realize the voice call function.

[0010] The beneficial effects of the utility model are:

[0011] The antenna of the utility model has a simple structure and a small size, and can be very suitably applied to wearable devices to realize a voice call function. Moreover, the antenna return loss and efficiency parameters fully meet the application requirements of wearable devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the antenna of the utility model;

[0013] Figure 2 This is the switch chip circuit diagram of the antenna of the utility model;

[0014] Figure 3 This is a return loss diagram of the antenna state 1 of the utility model;

[0015] Figure 4 This is a return loss diagram of the antenna state 2 of the utility model;

[0016] Figure 5 This is a return loss diagram of the antenna state three of the utility model;

[0017] Figure 6 This is the efficiency diagram of the antenna state 1 of the utility model;

[0018] Figure 7 This is the efficiency diagram of the antenna state 2 of the utility model;

[0019] Figure 8 This is the efficiency diagram of the antenna state three of the utility model.

[0020] Explanation of the numbers in the figure: P, PCB main board; R, metal ring; F, antenna feeding end; F1, first metal spring; G, antenna grounding pin; G1, second metal spring; C, switch chip; S1, first clearance slot; S2, second clearance slot. DETAILED DESCRIPTION

[0021] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0022] like Figure 1 As shown, a metal ring antenna structure suitable for wearable devices includes a PCB motherboard P. The wearable device takes a watch as an example. The PCB motherboard P is also the motherboard of the watch. All relevant components are arranged on the PCB motherboard P. In this embodiment, the PCB motherboard P is simplified, and the description of components such as speakers on the PCB motherboard P is omitted. Only components that may affect the performance of the 4G / 5G antenna, such as a display screen and a battery, are placed. The outer ring of the PCB motherboard P is provided with a metal ring R, and the metal ring R is also a part of the watch casing. This metal ring R is the main part of the 4G / 5G antenna to realize the voice call function. A clearance groove of a certain width is left between the metal ring R and the PCB motherboard P. The width of the clearance groove affects the performance of the antenna. Generally speaking, the wider the width, the better the performance of the antenna, but the PCB The main board P also needs to have enough ground to ensure the performance of the antenna. Therefore, when debugging the antenna, it is necessary to balance the width of the clearance slot and the PCB main board P, and it is necessary to ensure that no metal devices are arranged in the clearance slot area. Taking a watch as an example, the width of the clearance slot can be preferably 3 mm. The metal ring R is provided with an antenna feed terminal F and an antenna grounding pin G. The PCB main board P is provided with a first metal shrapnel F1 and a second metal shrapnel G1. The lead-out pin of the antenna feed terminal F on the metal ring R is connected to the PCB main board P by connecting the first metal shrapnel F1. The antenna grounding pin G on the metal ring R is connected to the second metal shrapnel G1. The second metal shrapnel G1 is connected to a single-pole four-throw switch chip C on the PCB main board P through a corresponding circuit for switching different states of the antenna to expand the working frequency band of the antenna and improve performance.

[0023] like Figure 2 As shown, the switch chip C includes an access point and circuits from the first to the fourth ports, wherein the access point is connected to the second metal spring G1. In addition, depending on the switch chip C, other related conventional peripheral circuits may be added near the access point. The first port is connected to the ground terminal through an inductor, and the inductor value is selected appropriately according to the antenna debugging situation. In this embodiment, the inductor value is 22nh; the second port is connected in series to the ground terminal through a capacitor and an inductor to form a series resonant circuit. In this embodiment, a 26pf capacitor and a 2.2nh inductor are connected in series to the ground; the third port is connected to the ground terminal through a capacitor, and a 12pf capacitor is used to connect the ground in this embodiment; the fourth port is an unloaded position, and this circuit state is not used temporarily in this embodiment. Capacitors and inductors may be reserved later according to the actual antenna debugging situation; technicians may enable the switch chip C to be selected on the corresponding port circuit according to the high and low levels to realize the switching of different states of the antenna, expand the working frequency band of the antenna, and improve the performance.

[0024] The clearance slot from the antenna feed end F to the antenna grounding pin G clockwise is the first clearance slot S1, and its length and width control the low frequency of the antenna; the clearance slot from the antenna feed end F to the antenna grounding pin G counterclockwise is the second clearance slot S2, and its length and width control the high frequency of the antenna; therefore, when actually selecting the specific position of the antenna grounding pin G, it is necessary to balance the low-frequency and high-frequency resonance positions and select a suitable antenna grounding pin G position.

[0025] The antenna structure also includes a display screen and a battery. The screen with a display area has physical properties equivalent to metal properties. The larger the area, the more it affects the performance of the antenna. Therefore, the display area of ​​the display screen is less than or equal to the copper area of ​​the PCB motherboard P, and the battery area is less than or equal to the copper area of ​​the PCB motherboard P.

[0026] like Figure 3 , Figure 4 and Figure 5 As shown in the figure, they are the return loss diagrams of antenna state 1, state 2 and state 3. Since the simulation is used on a wearable device, a watch is used as an example in this embodiment, and the return loss and efficiency of the antenna are the results of simulation on a human hand. It can be seen from the figure that due to the very low frequency and the metal ring R of the antenna body, the return loss is slightly lower than the performance of ordinary antennas; currently the return loss of the three low-frequency states is between -1dB and 3dB; the return loss of GPS1575MHz is about -5dB; the return loss of high frequency 1710MHz to 2200MHz is between -4dB and -9dB; the return loss of general antennas is about -5dB, but in actual projects, the overall efficiency of the antenna still needs to be considered, and the return loss is only a reference for debugging the antenna.

[0027] like Figure 6 , Figure 7 and Figure 8 As shown in the figure, they are the efficiency diagrams of antenna state 1, state 2 and state 3. It can be seen from the figure that the efficiency of the low-frequency antenna in the three states is above -14dB, and the high-frequency is above -11dB. Such performance fully meets the requirements of production applications.

[0028] In addition, it should be noted that, unless otherwise specified or indicated, the terms "first", "second", etc. in the specification are only used to distinguish the various components, elements, steps, etc. in the specification, and are not used to indicate the logical relationship or sequential relationship between the various components, elements, steps, etc.

[0029] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A metal ring antenna structure suitable for wearable devices, comprising a PCB motherboard (P), characterized in that: The outer ring of the PCB main board (P) is provided with a metal ring (R), a clearance groove of a certain width is left between the metal ring (R) and the PCB main board (P), an antenna feeding terminal (F) and an antenna grounding pin (G) are provided on the metal ring (R), and a first metal spring (F1) and a second metal spring (G1) are provided on the PCB main board (P). The lead-out pin of the antenna feeding terminal (F) on the metal ring (R) is connected to the PCB main board (P) by connecting the first metal spring (F1), the antenna grounding pin (G) on the metal ring (R) is connected to the second metal spring (G1), and the second metal spring (G1) is connected to a single-pole four-throw switch chip (C) on the PCB main board (P) through a corresponding circuit, which is used for switching different states of the antenna, so as to expand the working frequency band of the antenna and improve the performance.

2. The metal ring antenna structure suitable for wearable devices according to claim 1, characterized in that: The switch chip (C) comprises an access point and circuits of ports 1 to 4, wherein the access point is connected to a second metal spring (G1), the first port is connected to the ground via an inductor, the second port is connected to the ground via a capacitor and an inductor in series, the third port is connected to the ground via a capacitor, and the fourth port is an unloaded position. The switch chip (C) is selected on the corresponding port circuit according to high and low levels to realize switching of different states of the antenna.

3. The metal ring antenna structure suitable for wearable devices according to claim 1 or 2, characterized in that: The clearance slot from the antenna feed end (F) to the antenna grounding pin (G) in a clockwise direction is the first clearance slot (S1), and its length and width control the low frequency of the antenna. The clearance slot from the antenna feed end (F) to the antenna grounding pin (G) in a counterclockwise direction is the second clearance slot (S2), and its length and width control the high frequency of the antenna.

4. The metal ring antenna structure suitable for wearable devices according to claim 3, characterized in that: The antenna structure also includes a display screen and a battery, wherein the display area of ​​the display screen is smaller than or equal to the copper area of ​​the PCB main board (P), and the battery area is smaller than or equal to the copper area of ​​the PCB main board (P).

5. The metal ring antenna structure suitable for wearable devices according to claim 1, characterized in that: The metal ring (R) is a part of the structure of the corresponding wearable device shell to realize the voice call function.

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