Miniature Bluetooth LDS antenna

Abstract

The invention discloses a miniature Bluetooth LDS antenna, and relates to the field of Bluetooth antennae, and the miniature Bluetooth LDS antenna comprises a substrate, an antenna housing, an LDS antenna, a miniature spring ejector pin, a radio frequency feed line and a grounding line. The substrate is arranged in the antenna shell, and the LDS antenna is arranged on the top surface in the antenna shell; the substrate is provided with a clearance area and a non-clearance area; the micro spring ejector pin, the radio frequency feed circuit and the grounding circuit are arranged in the clearance area; the interior of the non-clearance area is coated with copper to form the radiation ground of the LDS antenna; the radio frequency feed line and the grounding line are connected with the LDS antenna through the miniature spring ejector pin. According to the invention, the design flexibility of the antenna can be improved, and the miniaturization of the product is realized.

Description

Technical Field

[0001] The present application relates to the field of Bluetooth antennas, and in particular to a miniature Bluetooth LDS antenna. Background Art

[0002] With the continuous development of wireless communication technology, especially the widespread application of Bluetooth antennas, the demand for miniaturized and high-performance antennas is increasing. As one of the key parts of Bluetooth devices, the performance of Bluetooth antennas directly affects the communication quality and reliability of Bluetooth devices.

[0003] The most commonly used traditional Bluetooth antenna is the on-board antenna, which is installed on the substrate. Although the on-board antenna can achieve good performance, its performance depends on the relatively large substrate area, which is difficult to meet the design requirements in terms of miniaturized devices. The main problems of traditional Bluetooth antennas are: the large substrate area they occupy and the inflexible antenna position setting. Summary of the invention

[0004] The purpose of this application is to provide a miniature Bluetooth LDS antenna, which can improve the design flexibility of the antenna and achieve miniaturization of the product.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] The present application provides a miniature Bluetooth LDS antenna, comprising: a substrate, an antenna housing, an LDS antenna, a miniature spring ejector pin, a radio frequency feed circuit, and a ground circuit;

[0007] The substrate is arranged inside the antenna housing, and the LDS antenna is arranged on the inner top surface of the antenna housing;

[0008] The substrate is provided with a clearance area and a non-clearance area; the micro spring ejector, the RF feed circuit and the ground circuit are arranged in the clearance area; the non-clearance area is covered with copper to form a ground for LDS antenna radiation;

[0009] The radio frequency feeding circuit and the grounding circuit are connected to the LDS antenna through the micro spring pins.

[0010] Optionally, the substrate is a PCB board, and the dielectric constant of the PCB board is 4.4 and the thickness is 0.8 mm.

[0011] Optionally, the horizontal cross-section of the antenna shell is a square, the thickness of the antenna shell is 1 mm, the material of the antenna shell is an LCP-based material, and the dielectric constant is 2.2.

[0012] Optionally, the LDS antenna includes: a first antenna arm, a second antenna arm and a third antenna arm; the first antenna arm is arranged in parallel with the third antenna arm, one end of the first antenna arm is connected to one end of the second antenna arm, and the other end of the second antenna arm is connected to one end of the third antenna arm; the first antenna arm, the second antenna arm and the third antenna arm are located in the same plane.

[0013] Optionally, the micro spring ejector includes: a first micro spring ejector and a second micro spring ejector.

[0014] Optionally, the top end of the first micro-spring pin is connected to one end of the third antenna arm, the bottom end of the first micro-spring pin is connected to the ground circuit, the top end of the second micro-spring pin is connected to the other end of the third antenna arm, and the bottom end of the second micro-spring pin is connected to the RF feeding circuit.

[0015] Optionally, the top of the first spring ejector pin and the top of the second micro spring ejector pin are semicircular retractable spring structures.

[0016] Optionally, the radii of the bottom ends of the first micro spring pin and the second micro spring pin are both 0.75 mm, the radii of the top ends of the first micro spring pin and the second micro spring pin are both 0.2 mm; and the heights of the first micro spring pin and the second micro spring pin are both ≥2 mm.

[0017] Optionally, the RF feeding circuit is provided with a RF feeding point, and the RF feeding point is a transmission port for RF signals.

[0018] Optionally, the RF feeding line and the grounding line are both copper conducting strips.

[0019] According to the specific embodiments provided in this application, this application has the following technical effects:

[0020] (1) The LDS antenna is set on the inner top surface of the antenna housing without occupying additional space, which gives the LDS antenna greater freedom and flexibility in layout, and can better optimize the product structure and achieve product miniaturization.

[0021] (2) The present application transmits the RF signal of the RF feed circuit to the LDS antenna through a micro spring pin, thereby isolating the LDS antenna from the substrate, avoiding interference from components inside the substrate, ensuring the signal quality of the micro Bluetooth LDS antenna, and improving the space utilization of the product, allowing the entire space volume to reach a micro level. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A top view of a miniature Bluetooth LDS antenna provided in one embodiment of the present application;

[0024] Figure 2 A front view of a miniature Bluetooth LDS antenna provided in one embodiment of the present application;

[0025] Figure 3 It is a schematic diagram of the reflection coefficient (S11) result of the miniature Bluetooth LDS antenna;

[0026] Figure 4 Schematic diagram of input impedance result (Y1) of micro Bluetooth LDS antenna;

[0027] Figure 5 This is a schematic diagram of the voltage standing wave ratio (VSWR) results of the miniature Bluetooth LDS antenna;

[0028] Figure 6 This is a schematic diagram of the stereoscopic directional gain (Gain) direction of the miniature Bluetooth LDS antenna at the 2.45GHz frequency point;

[0029] Figure 7 This is a schematic diagram of the radiation direction when Phi is 0 degrees at the 2.45GHz frequency point;

[0030] Figure 8 This is a schematic diagram of the radiation direction when the Phi is 90 degrees at the 2.45GHz frequency. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] Bluetooth LDS (Laser Direct Structuring) antenna can achieve miniaturization while ensuring performance. Bluetooth LDS technology is a laser direct structuring technology that uses a computer to control the movement of the laser according to the trajectory of the conductive pattern, and projects the laser onto the molded three-dimensional plastic device. In a few seconds, the circuit pattern is activated, which not only improves the design flexibility of the antenna, but also helps to achieve a more compact product design.

[0033] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0034] In an exemplary embodiment, Figure 1-Figure 2 As shown, a miniature Bluetooth LDS antenna is provided, including: a substrate 6, an antenna housing 2, an LDS antenna (including a first antenna arm 31, a second antenna arm 32 and a third antenna arm 33), a miniature spring pin 5, a radio frequency feeding circuit 4 and a ground circuit 7.

[0035] The horizontal cross-section of the antenna housing 2 is square, the thickness can be changed, preferably 1 mm, the material dielectric constant is 2.2, and the material is LCP (Liquid Crystal Polymer) based material, which has good heat resistance and mechanical strength, and has excellent dielectric properties and stability in antenna design.

[0036] The substrate 6 is arranged inside the antenna housing 2. The substrate 6 is provided with a non-clearance area 1 and a clearance area other than the non-clearance area 1. The clearance area is provided with a micro spring ejector pin 5, a radio frequency feed line 4 and a ground line 7. The non-clearance area 1 is covered with copper to form the ground for the LDS antenna to radiate.

[0037] In a specific embodiment, the substrate 6 is a PCB board, and the dielectric constant of the PCB board is 4.4 and the thickness is 0.8 mm.

[0038] The grounding circuit 7 and the RF feeding circuit 4 are both connected to the LDS antenna through the micro spring pin 5. The grounding circuit 7 is used to adjust the impedance of the LDS antenna; the RF feeding circuit 4 uses the RF feeding point 8 set at its right end as the transmission port of the RF signal to transmit the RF signal to the LDS antenna.

[0039] In a specific embodiment, the RF feed line 4 and the ground line 7 are both copper conductive strips, and the ground line 7 is connected to the non-clearance area 1 to form a ground loop. The RF feed line 4 and the ground line 7 are formed by printing on the substrate 6, which is easy to produce and operate, and has low cost.

[0040] The LDS antenna is arranged on the inner top surface of the antenna housing 2. The LDS antenna includes a first antenna arm 31, a second antenna arm 32 and a third antenna arm 33. The first antenna arm 31 is arranged in parallel with the third antenna arm 33, one end of the first antenna arm 31 is connected to one end of the second antenna arm 32, and the other end of the second antenna arm 32 is connected to one end of the third antenna arm 33. The first antenna arm 31, the second antenna arm 32 and the third antenna arm 33 are located in the same plane, and the second antenna arm 32 is bent perpendicularly to the first antenna arm 31 and the third antenna arm 33.

[0041] The lengths of the first antenna arm 31, the second antenna arm 32 and the third antenna arm 33 can be changed to adjust the resonance point of the LDS antenna. In a specific embodiment, the length of the first antenna arm 31 is 19 mm, the length of the second antenna arm 32 is 4.5 mm, the length of the third antenna arm 33 is 4.2 mm, and their widths are all 1 mm.

[0042] The micro spring pin 5 includes a first micro spring pin 51 and a second micro spring pin 52. Preferably, the center distance between the bottom ends of the first micro spring pin 51 and the second micro spring pin 52 is 3 mm. The top of the first micro spring pin 51 is used to connect one end of the third antenna arm 33, and the bottom end is connected to the ground line 7. By adjusting the position of the first micro spring pin 51 in the clearance area, the resonant frequency of the LDS antenna can be effectively controlled, and the impedance matching of the LDS antenna can be further optimized without additional circuit elements. The top of the second micro spring pin 52 is used to connect the other end of the third antenna arm 33, and the bottom end of the second micro spring pin 52 is connected to the RF feed line 4, which is used to transmit the RF signal to the LDS antenna through the second micro spring pin 52.

[0043] The bottom end of the first micro spring pin 51 and the bottom end of the second micro spring pin 52 are welded to the substrate 6 to form a stable structure. The top end of the first micro spring pin 51 and the top end of the second micro spring pin 52 are semicircular retractable spring structures that can be embedded in the inner top surface of the antenna housing 2, and the resonant frequency and input impedance can be adjusted by flexibly changing the overall height. Preferably, the bottom end of the first micro spring pin 51 and the bottom end of the second micro spring pin 52 have a radius of 0.75 mm, and the top end has a radius of 0.2 mm.

[0044] The height of the first micro pogo pin 51 and the second micro pogo pin 52 is ≥ 2 mm, so that the performance of the LDS antenna is better. Preferably, the height of the first micro pogo pin 51 and the second micro pogo pin 52 is 2.2 mm.

[0045] In the present application, the LDS antenna is arranged on the inner top surface of the antenna housing 2, and the RF signal is transmitted to the LDS antenna by a micro spring pin 5. Compared with the traditional Bluetooth antenna, the interference of components inside the substrate is avoided, the overall space utilization is improved, and the bandwidth and gain performance of the micro Bluetooth LDS antenna in the 2.4GHz frequency band are guaranteed.

[0046] from Figure 3 It can be seen that the LDS antenna produces good resonance at 2.45GHz, and the LDS antenna achieves a reflection coefficient bandwidth of -10dB at 2.398-2.488GHz, which is sufficient to cover the 2.4GHz Bluetooth operating frequency band.

[0047] The matching degree of input impedance will directly affect the efficiency of power transmission. Figure 4 It can be seen that the input impedance is close to 50 ohms at the center frequency of 2.45 GHz, indicating that the LDS antenna and the RF feed line impedance match well. Figure 5 It can be seen that in the 2.4 GHz frequency band, the bandwidth when VSWR < 2 is 2.3965-2.4895 GHz, which is very close to the reflection coefficient bandwidth of -10 dB, indicating that good transmission efficiency has been achieved.

[0048] Figure 6 This is the three-dimensional directional gain radiation pattern of the miniature Bluetooth LDS antenna at the 2.45GHz frequency point. Its directional gain performance is high, which can make the miniature Bluetooth LDS antenna have better signal coverage and longer transmission distance.

[0049] Figure 7 and Figure 8 These are the radiation patterns of Phi at 2.45GHz frequency points at 0 degrees and 90 degrees respectively. It can be seen that the radiation direction performance is good.

[0050] This application has the following advantages:

[0051] (1) Miniaturization: Compared with the existing traditional Bluetooth antenna, the LDS antenna of the miniature Bluetooth LDS antenna is designed to be inside the electronic device (antenna housing), which does not require an increase in the area of ​​the substrate or additional installation space. This is particularly important for miniaturized electronic devices because they often pursue more compact dimensions. In particular, for some terminal devices, there are strict restrictions on the thickness of the entire electronic device, so this application can take into account the requirements of wide bandwidth and low height at the same time.

[0052] (2) Design flexibility: LDS antennas can be designed on the surface of electronic devices. By first designing the appearance of the electronic device, the LDS antenna can be directly designed on the surface of the electronic device without occupying additional space. This design method allows the LDS antenna to have greater freedom and flexibility in layout, which can better optimize the product structure and achieve product miniaturization.

[0053] (3) Avoid crosstalk and improve product space utilization: This application introduces a micro spring pin, which not only serves as a support carrier for connecting the substrate and the LDS antenna to achieve electrical connection and support, but also can isolate the LDS antenna from the substrate, avoiding interference from components inside the substrate, ensuring the signal quality of the Bluetooth LDS antenna, and at the same time improving the space utilization of the product, allowing the entire space volume to reach a micro level.

[0054] (4) Performance optimization: By precisely controlling the shape and position of the LDS antenna, the LDS antenna can achieve higher performance, such as better signal transmission efficiency and lower signal loss. In addition, the LDS antenna can be optimized for a specific frequency to achieve better communication quality.

[0055] (5) Durability and stability: Since LDS antennas are molded directly onto the product housing or other components, they are less susceptible to physical damage and are more durable than traditional welded or glued antennas. This also means that antenna performance can remain stable over the life of the device.

[0056] (6) Multi-scenario applicability: LDS antennas are not limited to Bluetooth communications, but can also be applied to other wireless communication technologies such as Wi-Fi, GPS, etc., which provides device manufacturers with more options.

[0057] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A miniature Bluetooth LDS antenna, characterized in that: include: Substrate, antenna housing, LDS antenna, micro spring ejector pin, RF feed line and ground line; The substrate is arranged inside the antenna housing, and the LDS antenna is arranged on the inner top surface of the antenna housing; The substrate is provided with a clearance area and a non-clearance area; The micro spring ejector pin, the RF feed circuit and the ground circuit are arranged in the clearance area; the non-clearance area is covered with copper to form a ground for LDS antenna radiation; The radio frequency feeding circuit and the grounding circuit are connected to the LDS antenna through the micro spring pins.

2. The miniature Bluetooth LDS antenna according to claim 1, characterized in that: The substrate is a PCB board, and the dielectric constant of the PCB board is 4.4 and the thickness is 0.8 mm.

3. The miniature Bluetooth LDS antenna according to claim 1, characterized in that: The horizontal cross-section of the antenna shell is a square, the thickness of the antenna shell is 1 mm, and the material of the antenna shell is an LCP-based material with a dielectric constant of 2.

2.

4. The miniature Bluetooth LDS antenna according to claim 1, characterized in that: The LDS antenna includes: a first antenna arm, a second antenna arm and a third antenna arm; the first antenna arm is arranged in parallel with the third antenna arm, one end of the first antenna arm is connected to one end of the second antenna arm, and the other end of the second antenna arm is connected to one end of the third antenna arm; the first antenna arm, the second antenna arm and the third antenna arm are located in the same plane.

5. The miniature Bluetooth LDS antenna according to claim 4, characterized in that: The micro spring ejector includes: a first micro spring ejector and a second micro spring ejector.

6. The miniature Bluetooth LDS antenna according to claim 5, characterized in that: The top end of the first micro-spring pin is connected to one end of the third antenna arm, the bottom end of the first micro-spring pin is connected to the ground circuit, the top end of the second micro-spring pin is connected to the other end of the third antenna arm, and the bottom end of the second micro-spring pin is connected to the RF feeding circuit.

7. The miniature Bluetooth LDS antenna according to claim 5, characterized in that: The top end of the first spring ejector pin and the top end of the second micro spring ejector pin are semicircular retractable spring structures.

8. The miniature Bluetooth LDS antenna according to claim 5, characterized in that: The radii of the bottom ends of the first micro spring ejector pin and the bottom ends of the second micro spring ejector pin are both 0.75 mm, and the radii of the top ends of the first micro spring ejector pin and the second micro spring ejector pin are both 0.2 mm; the heights of the first micro spring ejector pin and the second micro spring ejector pin are both ≥2 mm.

9. The miniature Bluetooth LDS antenna according to claim 1, characterized in that: The RF feeding circuit is provided with a RF feeding point, and the RF feeding point is a transmission port for RF signals.

10. The miniature Bluetooth LDS antenna according to claim 1, characterized in that: The radio frequency feeding line and the grounding line are both copper conducting strips.

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