This application claims priority to Chinese Patent Application No. 201910146577.6, filed with the China National Intellectual Property Administration on Feb. 27, 2019 and entitled “GROUND PLANE RADIATION ANTENNA SOLUTION”, and priority to Chinese Patent Application No. 201910614002.2, filed with the China National Intellectual Property Administration on Jul. 8, 2019 and entitled “ANTENNA APPARATUS AND ELECTRONIC DEVICE”, which are incorporated herein by reference in their entireties.
The present invention relates to the field of antenna technologies, and in particular, to an antenna apparatus applied to an electronic device.
To bring a more comfortable visual experience to users, the bezel-less screen industry design (industry design, ID) has become a design trend of portable electronic devices such as mobile phones. The bezel-less screen means a large screen-to-body ratio (usually over 90%). The bezel width of the bezel-less screen is greatly reduced, and internal components of the phone, such as the front-facing camera, receiver, fingerprint reader, and antenna, need to be rearranged. Especially for the antenna design, the clearance area is reduced and the antenna space is further compressed. However, the size, bandwidth, and efficiency of the antenna are correlated and affect each other. If the antenna size (space) is reduced, the efficiency-bandwidth product (efficiency-bandwidth product) of the antenna is definitely reduced. Therefore, the bezel-less screen ID poses great challenges to the antenna design of mobile phones.
An antenna design form commonly used in an existing electronic device such as a mobile phone may be a planar inverted F (planar inverted F) antenna, an inverted F (inverted F) antenna, a monopole (monopole) antenna, a T-shaped antenna, a loop (loop) antenna, or the like. For these antenna designs, the antenna length needs to be at least one quarter to one half of a low-frequency wavelength. This has a high requirement on the antenna space.
How to design an antenna in limited space and meet antenna performance requirements is a research direction in the industry.
According to the embodiments of the present invention, an antenna apparatus and an electronic device are provided, can effectively excite a ground plane to generate radiation, and are applicable to a bezel-less electronic device whose antenna space is sharply reduced, because a radiation capability of the ground plane is not affected by a size of a clearance between a display screen and the ground plane.
According to a first aspect, this application provides an antenna apparatus. As shown in
The ground plane 15 includes a first side (for example, a lateral side 21-1) and a second side (for example, a lateral side 21-5) that are opposite to each other, and a third side (for example, a bottom side 21-7) and a fourth side (for example, a top side 21-3) that are opposite to each other.
The exciting element 23 may have a first branch 29-2 and two second branches (29-1 and 29-3). The second branch 29-1 and the second branch 29-3 may be respectively connected to two ends of the first branch 29-2. An end of the second branch 29-1 that is away from the first branch 29-2 is connected to the ground plane 15, and an end of the second branch 29-3 that is away from the first branch 29-2 is connected to the ground plane 15. The second branch 29-1 and the second branch 29-3 may be used to set the first branch 29-2 on the ground plane 15, and a gap is formed between the first branch 29-2 and the ground plane 15.
The exciting element 23 may be set on the ground plane 15 in proximity to the first side of the ground plane 15. Herein, the proximity may mean that a distance between the exciting element 23 and the first side is less than a specific distance, for example, 4 mm. The specific distance is not limited to 4 mm, and may alternatively be a value such as 3 mm, 2 mm, or 1 mm. In this case, a distance L1 from the exciting element 23 to the first side is less than a distance L2 from the exciting element 23 to the second side.
A difference between a distance p1 from a first end of the exciting element 23 to the third side and a distance p2 from a second end of the exciting element 23 to the fourth side is less than a first value, for example, 15 mm. The first value is not limited to 15 mm, and may alternatively be a value such as 12 mm or 20 mm. The first end of the exciting element 23 is an end close to the third side, and the second end of the exciting element 23 is an end close to the fourth side.
A feeding port 27 may be disposed on the exciting element 23, and a signal source is located in the feeding port 27. A first slot may be disposed on the first branch 29-2 of the exciting element 23, and a first capacitor may be connected in series between two parts of the first branch on both sides of the first slot. The first capacitor may be configured to implement a codirectional current distributed on the exciting element 23.
It can be seen that, in the antenna apparatus provided in the first aspect, an exciting element is set above a ground plane of an electronic device (for example, a mobile phone), and the exciting element is fed to effectively excite the ground plane to generate radiation. In this way, because a radiation capability of the ground plane is not affected by a size of a clearance between a display screen and the ground plane, the antenna solution provided in this application is applicable to a bezel-less electronic device whose antenna space is sharply reduced. In addition, the ground plane serves as one of main radiation apertures of an electronic device (for example, a mobile phone), and exciting the ground plane to generate radiation can significantly improve antenna performance.
With reference to the first aspect, in some embodiments, the exciting element 23 may be parallel to the first side (for example, the lateral side 21-1) of the ground plane 15, or a smaller included angle may be presented between the exciting element 23 and the first side (for example, the lateral side 21-1) of the ground plane 15. In other words, the exciting element 23 and the first side (for example, the lateral side 21-1) of the ground plane 15 may be nearly parallel. The smaller included angle may be less than a first angle, such as 5°. The first angle is not limited to 5°, and may alternatively be an angle such as 3° or 7°. In this case, an included angle α between the exciting element 23 and the first side is less than an included angle β between the exciting element 23 and the third side. The exciting element 23 may be parallel to the first side of the ground plane 15. In other words, the included angle α is equal to 0°. In this case, the exciting element 23 may excite the ground plane 15 to generate a stronger current at the first side, and the exciting element 23 is more likely to excite the ground plane 15 to generate resonance.
With reference to the first aspect, m some embodiments, the first slot may be disposed in the middle of the first branch 29-2, so that the codirectional current on the exciting element 23 is stronger, and the ground plane 15 is more likely to be excited to generate radiation. The first capacitor may be a lumped capacitor or a distributed capacitor (for example, a distributed capacitor formed by disposing a gap on the exciting element 23).
With reference to the first aspect, in some embodiments, a feeding form at the feeding port 27 may include, but is not limited to, the following two manners:
In an implementation, as shown in
In another implementation, as shown in
With reference to the first aspect, in some embodiments, the first branch 29-2 may be a horizontal branch parallel to the ground plane 15. Optionally, the second branch 29-1 and the second branch 29-3 may be vertical branches perpendicular to the ground plane 15, and are used to suspend the first branch 29-2 on the ground plane 15.
With reference to the first aspect, in some embodiments, the exciting element 23 may be parallel to the first side. In this case, the included angle α=0 and the included angle β=90°. In this case, the exciting element 23 is more likely to excite the ground plane 15 to generate radiation.
With reference to the first aspect, in some embodiments, the exciting element 23 may be set on the first side of the ground plane. In this case, L1 is equal to 0. In this case, the exciting element 23 is more likely to excite the ground plane 15 to generate radiation. In other words, a closer proximity of the exciting element 23 to the first side indicates that the ground plane 15 is more likely to be excited to generate radiation.
With reference to the first aspect, in some embodiments, the distance p1 and the distance p2 may be equal, and both are equal to (Lg−Le)/2. In this case, the exciting element 23 may be set in the middle of the ground plane in proximity to the first side, and the exciting element 23 is more likely to excite the ground plane 15 to generate resonance.
With reference to the first aspect, in some embodiments, the matching network integrated at the feeding port may include a capacitor C and an inductor L, the capacitor C is connected in series to the feeding port, and the inductor L is connected in parallel to the feeding port. The capacitor C may be referred to as a second capacitor, and the inductor L may be referred to as a first inductor.
With reference to the first aspect, in some embodiments, the antenna apparatus provided in this application may further implement a dual-band, a wide-band, or a multi-band, and may be implemented by using the matching network or adding more magnetic rings. Details are described below.
1. Dual-Band Antenna Solution Based on a Matching Network
To implement dual-band matching, the matching network may be: An LC parallel circuit (consisting of L2 and C2 connected in parallel) is connected in series after a capacitor C1 is connected in series, and finally an inductor L2 is connected in parallel. In other words, the matching network integrated at the feeding port may include: The capacitor C1, the LC parallel circuit, and the inductor L2 are connected in series, the capacitor C1 and the LC parallel circuit are connected in series to the feeding port once, and the inductor L2 is connected in parallel to the feeding port. The capacitor C1 may be referred to as a third capacitor, the inductor L2 may be referred to as a second inductor, the capacitor C2 in the LC parallel circuit may be referred to as a fourth capacitor, and the inductor L2 in the LC parallel circuit may be referred to as a third inductor. Optionally, the dual-band may be a low-band (for example, at 800 MHz) and a GPS L1 band (at 1.5 GHz). A configuration for the dual-band matching network may be as follows: C1=1 pF, L1=6 nH, C2=2.2 pF, and L2=4.5 nH.
2. Dual-Band, Wide-Band, or Multi-Band Antenna Solution Based on a Multi-Magnetic Ring
To implement a dual-band or a wide-band, a parasitic element (which may also be referred to as a parasitic magnetic ring) may be set on the ground plane 15. In other words, the antenna apparatus provided in this application may further include a parasitic element. On the ground plane 15, like the exciting element 23, the parasitic element may be set in proximity to the first side (for example, the lateral side 21-1) of the ground plane. Herein, the proximity may mean that a distance between the parasitic element and the first side (for example, the lateral side 21-1) of the ground plane is less than a specific distance (for example, 4 mm). In this case, a distance L3 from the parasitic element to the first side of the ground plane is less than a distance L4 from the parasitic element to the second side of the ground plane.
While the exciting element 23 excites the ground plane 15 to generate radiation, the ground plane 15 couples the parasitic element to generate radiation, thereby implementing dual-band radiation.
In some embodiments, the parasitic element may have a same structure as the exciting element 23. The parasitic element may have a third branch and two fourth branches. The third branch is similar to the first branch 29-2 in the exciting element 23, and the fourth branches are similar to the second branches 29-1 and 29-3 in the exciting element 23. Similar to the structure of the exciting element 23, the two fourth branches in the parasitic element may be respectively connected to two ends of the third branch. An end of the fourth branch that is away from the first branch is connected to the ground plane 15. The two fourth branches may be used to set the third branch on the ground plane 15, so that a gap is formed between the third branch and the ground plane 15. Like the exciting element 23, a capacitor may be connected in series on the parasitic element. The capacitor may be referred to as a fifth capacitor. To connect the fifth capacitor in series, a gap may be disposed on the third branch, and the fifth capacitor may be connected in series between two parts of the third branch on both sides of the gap. The gap may be referred to as a second slot.
The parasitic element is not limited to the parasitic magnetic ring having the same structure as the exciting element 23. To implement a multi-band or a wide-band, the parasitic element may alternatively be another antenna, such as a support antenna or a floating antenna. The support antenna may include an IFA antenna, an ILA antenna, and the like.
With reference to the first aspect, in some embodiments, to implement MIMO, the antenna apparatus provided in this application may include a plurality of antenna elements. One antenna element may have one exciting element 23, or may have one exciting element 23 and M (M is a positive integer) parasitic elements. The plurality of antenna elements may be disposed in proximity to the sides of the ground plane 15. In other words, in one antenna element, the exciting element 23 is set in proximity to edges of the ground plane, and the parasitic element is also set in proximity to the edges of the ground plane.
According to a second aspect, this application provides an electronic device. The electronic device includes a non-metal back cover and the antenna apparatus described in the first aspect.
To describe the technical solutions in the embodiments of this application more clearly, the following illustrates the accompanying drawings in the embodiments of this application.
The following describes the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention.
The technical solutions provided in this application are applicable to an electronic device that uses one or more of the following communications technologies: a Bluetooth (bluetooth, BT) communications technology, a global positioning system (global positioning system, GPS) communications technology, a wireless fidelity (wireless fidelity, Wi-Fi) communications technology, a global system for mobile communications (global system for mobile communications, GSM) communications technology, a wideband code division multiple access (wideband code division multiple access, WCDMA) communications technology, a long term evolution (long term evolution, LTE) communications technology, a 5G communications technology, a SUB-6G communications technology, and other future communications technologies. In this application, the electronic device may be a mobile phone, a tablet computer, a personal digital assistant (personal digital assistant, PDA), or the like.
The printed circuit board PCB 13 may be an FR-4 dielectric board, or may be a Rogers (Rogers) dielectric board, or may be a Rogers and FR-4 hybrid dielectric board, or the like. Herein. FR-4 is a code name for the grade of a flame-resistant material, and the Rogers dielectric board is a high-frequency board.
The back cover 19 is a back cover made of a non-conductive material, for example, a non-metal back cover such as a glass back cover or a plastic back cover.
The ground plane 15 is grounded, and may be disposed between the printed circuit board PCB 13 and the back cover 19. The ground plane 15 may also be referred to as a PCB ground plane. Specifically, the ground plane 15 may be a layer of metal etched on a surface of the PCB 13. This layer of metal may be connected to a metal middle frame (not shown) by using a series of metal elastomers, and is integrated with the metal middle frame. The ground plane 15 may be configured to ground an electronic element carried on the printed circuit board PCB 13. Specifically, the electronic element carried on the printed circuit board PCB 13 may be grounded by connecting the electronic element to the ground plane 15, to prevent a user from being electrocuted or device damage.
The bezel 17 may be disposed around edges of the ground plane 15, and may cover the printed circuit board PCB 13 and the ground plane 15 between the back cover 19 and the display screen 11 from lateral sides, to achieve dust-proof and waterproof purposes. The bezel 17 may be a metal bezel or a non-metal bezel. The bezel 17 may include a frame (which may be referred to as a top frame) 27-3 on a top of the electronic device 10, a frame (which may be referred to as a bottom frame) 27-7 at a bottom of the electronic device 10, and frames (which may be referred to as side frames) 27-1 and 27-5 on lateral sides of the electronic device 10. A front-facing camera (not shown), an earpiece (not shown), an optical proximity sensor (not shown), an ambient optical sensor (not shown), and the like may be disposed on the top of the electronic device 10. A USB charging interface (not shown), a microphone (not shown), and the like may be disposed at the bottom of the electronic device 10. A volume adjustment button (not shown) and a power button (not shown) may be disposed at the lateral sides of the electronic device 10.
Based on the internal environment of the electronic device shown in
The ground plane 15 may have a lateral side 21-1 and a lateral side 21-5 that are opposite to each other, and a top side 21-3 and a bottom side 21-7 that are opposite to each other. The sides of the ground plane 15 are respectively close to the frames of the bezel 17. Specifically, the lateral side 21-1 is close to the side frame 17-1, the top side 21-3 is close to the top frame 17-3, the lateral side 21-5 is close to the side frame 17-5, and the bottom side 21-7 is close to the bottom frame 17-7. Optionally, the ground plane 15 may be rectangular, the lateral side 21-1 and the lateral side 21-5 may be two opposite long sides, and the top side 21-3 and the bottom side 21-7 may be two opposite short sides.
The exciting element 23 may be set on the ground plane 15 in proximity to a side of the ground plane 15. This side may be referred to as a first side of the ground plane 15. Herein, the proximity may mean that a distance between the exciting element 23 and the first side of the ground plane 15 is less than a specific distance, such as 4 mm. A smaller distance between the exciting element 23 and the first side of the ground plane 15 indicates that the ground plane 15 is more likely to be excited to generate radiation. This will be analyzed in the following content, and details are not described herein. Optionally, the first side of the ground plane 15 may be a long side of the ground plane 15.
The exciting element 23 may be parallel to the first side of the ground plane 15, or a smaller included angle may be presented between the exciting element 23 and the first side of the ground plane 15. In other words, the exciting element 23 and the first side may be parallel or nearly parallel. The smaller included angle may be less than a first angle, such as 5°. The first angle is not limited to 5°, and may alternatively be an angle such as 3° or 7°.
The exciting element 23 may have a first branch 29-2 and two second branches (29-1, 29-3). The second branch 29-1 and the second branch 29-3 may be respectively connected to two ends of the first branch 29-2. The two ends of the first branch 29-2 may include one end 22-1 close to the top side 21-3 and one end 22-3 close to the bottom side 21-7. An end of the second branch 29-1 that is away from the first branch 29-2 is connected to the ground plane 15, and an end of the second branch 29-3 that is away from the first branch 29-2 is connected to the ground plane 15. The second branch 29-1 and the second branch 29-3 may be used to set the first branch 29-2 on the ground plane 15, and a gap is formed between the first branch 29-2 and the ground plane 15. In other words, the first branch 29-2 is not in contact with the ground plane 15. Optionally, the first branch 29-2 may be a horizontal branch parallel to the ground plane 15. Optionally, the second branch 29-1 and the second branch 29-3 may be vertical branches perpendicular to the ground plane 15, and are used to suspend the first branch 29-2 on the ground plane 15.
As shown in
As shown in
In an embodiment, as shown in
A matching network may be integrated at the feeding port 27. The matching network may be used to adjust (by adjusting an antenna transmit coefficient, an impedance, and the like) a band range covered by the antenna apparatus provided in this application. The matching network may include various structures that can implement impedance matching, such as an impedance conversion line or a lumped element network. A lumped element may include an element such as a capacitor or an inductor. Specifically, an input impedance of the antenna may be adjusted by changing a line width of the impedance conversion line and changing an electrical characteristic parameter (for example, a capacitance value and an inductance value) of a component in the lumped element network, to implement impedance matching.
The following describes a matching principle of the exciting element 23. When no matching element is used (namely, there is no matching network), the input impedance in an expected band (for example, 690 MHz to 96 W MHz) is mainly in an inductive area. In this case, S11 simulation of the antenna apparatus may be shown by curve a1 in
It can be seen that curve a1 has no resonance, curve a2 has one shallow resonance, and curve a3 has one deep resonance. In addition, antenna efficiency represented by curve b3 is clearly better than antenna efficiency represented by curves b1 and b2. In other words, good impedance matching may be performed on the exciting element 23 by first connecting the capacitor C in series to the feeding port and then connecting the inductor L in parallel, so that the exciting element 23 can effectively excite the ground plane 15 to generate radiation. In other words, the matching network integrated at the feeding port may include a capacitor C and an inductor L, the capacitor C is connected in series to the feeding port, and the inductor L is connected in parallel to the feeding port. The capacitor C may be referred to as a second capacitor, and the inductor L may be referred to as a first inductor.
The following uses a 900 MHz operating band as an example to describe an operating principle of the antenna apparatus provided in this application. It is assumed that the matching network integrated at the feeding port is that a 1 pF capacitor is first connected in series, and then a 4.5 nH inductor is connected in parallel. Current distribution of the antenna apparatus provided in this application operating at 900 MHz may be shown in
It can be seen that, by setting the exciting element 23 above the ground plane 15, feeding the exciting element 23, and setting an appropriate matching network at the feeding port, the ground plane 15 can be effectively excited to generate radiation. In this way, the requirement on antenna space can be reduced, the antenna solution provided in this application is applicable to a bezel-less 1D whose antenna space is sharply reduced, and antenna performance can be significantly improved.
The following describes application of the antenna design solution provided in this application to an actual overall system model.
For example, the distance p between the exciting element 23 shown in
It can be seen that a resonance position and a resonance depth of S11 simulation are basically the same when p=65 mm and p=45 mm, and peak system efficiency is about −6 dB. System efficiency when P=65 mm is slightly higher than that when P=45 mm. The reasons will be analyzed in the following content. In addition, an upper hemisphere proportion is about 45.18% when p=65 mm and 55.88% when p=65 mm. A higher upper hemisphere proportion indicates stronger radiation in a longitudinal direction of the antenna, namely, stronger radiation in the Z direction.
Apart from the distance p between the exciting element 23 and the bottom side 21-1 of the ground plane 15, the size of the ground plane 15, the size of the exciting element 23, and the distance w between the exciting element 23 and the lateral side 21-1 of the ground plane 15 may also be important parameters of the antenna apparatus provided in this application in an actual overall system model. Values of these parameters affect antenna performance. The following describes impact of a parameter on antenna performance in detail by using a single variable as a principle (namely, a single parameter is changed and other parameters remain unchanged).
(1) Impact of the Size of the Exciting Element 23 on Antenna Performance
If the length Le of the exciting element 23 increases, the resonance of the antenna is at a lower band, and the resonance depth becomes deeper. If the length Le of the exciting element 23 decreases, the resonance of the antenna is at a higher band, and the resonance depth becomes lower.
For example, using a 900 MHz operating band as an example,
Among the antenna performance at the different Les, when Le=45 mm, the antenna apparatus has the lowest resonance frequency (closest to 850 MHz), and the highest resonance depth (up to −8 dB). When Le=35 mm, the antenna apparatus has the highest resonance frequency (closest to 1 GHz) and the lowest resonance depth (about −4 dB). It can be seen that as the length Le becomes shorter from 45 mm to 40 mm and 35 mm, the resonance of the antenna moves towards a high frequency and the resonance depth becomes lower.
For a case in which the resonance becomes lower because the length Le of the exciting element 23 is reduced, the resonance depth may be increased by reducing the parallel inductor. For example, as shown in
If the height h of the exciting element 23 decreases, the resonance of the antenna moves towards a high frequency, and the resonance depth becomes lower.
For example, using a 900 MHz operating band as an example,
Among the antenna performance at different hs, when h=4 mm, the antenna apparatus has the lowest resonance frequency (about 900 MHz), and the highest resonance depth (up to −7 dB). When h=2 mm, the antenna apparatus has the highest resonance frequency (close to 1 GHz) and the lowest resonance depth (about −4 dB). It can be seen that as the height h decreases from 4 mm to 3 mm and 2 mm, the resonance of the antenna moves towards a high frequency and the resonance depth becomes lower.
For a case in which the resonance moves towards a high frequency because the height h of the exciting element 23 is reduced, the resonance may return to a low frequency by increasing the length Le. For example, as shown in
(2) Impact of the Position of the Exciting Element 23 on the Ground Plane 15 on Antenna Performance
The position of the exciting element 23 may be embodied by parameters of two dimensions: a distance w between the exciting element 23 and the first side (for example, the lateral side 21-1) of the ground plane, and a distance p between the exciting element 23 and the third side (for example, the bottom side 21-7) of the ground plane. The first side and the third side may be two connected sides of the ground plane 15, and may be perpendicular to each other.
2-A. Impact of the Distance w on Antenna Performance
A smaller distance w indicates that the exciting element 23 is closer to the lateral side 21-1 of the ground plane 15. When w=0 mm, it indicates that the exciting element 23 is set at the lateral side 21-1. A larger distance w indicates that the exciting element 23 is closer to the middle of the ground plane 15 in the Y direction.
Reducing the distance w may cause the resonance of the antenna to move towards the low frequency, and increase the resonance depth. Increasing the distance w can cause the resonance of the antenna to moves toward the high frequency, and reduce the resonance depth. This is because an intrinsic current of the ground plane 15 is mainly concentrated on the ground plane 15 due to the edge effect. When the exciting element 23 moves towards the middle of the ground plane 15 (that is, w becomes larger), the codirectional current on the exciting element 23 is difficult to couple to the intrinsic current of the ground plane 15. Therefore, it is difficult to excite the ground plane 15 to generate radiation.
For example, using a 900 MHz operating band as an example,
Among the antenna performance at different ws, when w=0 mm, the antenna apparatus has the lowest resonance frequency (about 900 MHz), and the lowest resonance depth (up to −6 dB). When w=4 mm, the antenna apparatus has the highest resonance frequency (close to 1 GHz), and the lowest resonance depth (about −3 dB). It can be seen that as the height w increases from 0 mm to 2 mm and 4 mm, the resonance of the antenna moves towards high frequency, and the resonance depth becomes lower, and the peak efficiency and bandwidth of the system also decrease significantly.
In addition, a metal bezel (d is not equal to 0) is disposed at lateral sides of the ground plane 15, so that the resonance of the antenna moves towards high frequency, and the resonance depth becomes lower. This is because the metal bezel may be equivalent to an epitaxy of the ground plane 15, and the intrinsic current of the ground plane 15 is mainly concentrated on the metal bezel due to the edge effect. This is equivalent to outward expansion of the ground plane 15. In this case, the system efficiency peak and bandwidth of the antenna also decrease.
For example, using a 900 MHz operating band as an example, as shown in
2-B. Impact of the Distance p on Antenna Performance
A smaller distance p indicates that the exciting element 23 is closer to the bottom side 21-7 of the ground plane 15. A larger distance p indicates that the exciting element 23 is farther away from the bottom side 21-7 of the ground plane 15 in the Z direction.
Assuming that the length Lg of the ground plane 15 is 140 mm, and the length of the exciting element 23 is 40 mm, when p=50 mm, p=(Lg−Le)/2. This may indicate that the exciting element 23 is disposed in the middle of the ground plane 15 in the Z direction. Increasing p (for example, p=50 mm+10 mm) or decreasing p (for example, p=50 mm-10 mm) causes the exciting element 23 to deviate from the middle of the ground plane 15. This may result in a lower resonance depth of the antenna, smaller peak efficiency of the system, and a smaller bandwidth. This is because the ground plane 15 has the strongest intrinsic current in the middle of the ground plane 15 in the Z direction, and the intrinsic current becomes weaker at positions away from the middle. When the exciting element 23 is away from the middle of the ground plane 15 in the Z direction, coupling between the codirectional current on the exciting element 23 and the intrinsic current of the ground plane 15 becomes weaker, and the ground plane 15 is unlikely to be excited to generate radiation, causing poor antenna performance.
For example, using a 900 MHz operating band as an example,
In addition, a closer proximity of the exciting element 23 to the bottom side 21-7 of the ground plane 15 (namely, a smaller p) indicates a larger upper hemisphere proportion of the antenna radiation pattern, and stronger radiation in the longitudinal direction of the antenna, namely, stronger radiation in the Z direction. A longer distance between the exciting element 23 and the bottom side 21-7 of the ground plane 15 (that is, a larger p) indicates a smaller upper hemisphere proportion of the antenna radiation pattern, and weaker radiation in the longitudinal direction of the antenna, namely, weaker radiation in the Z direction.
For example, using a 900 MHz operating band as an example,
(3) Impact of the Size of the Ground Plane 15 on Antenna Performance
The size of the ground plane 15 may be embodied by parameters of two dimensions: a length Lg of the ground plane 15 and a width Wg of the ground plane 15.
3-A. Impact of the Length Lg on Antenna Performance
Assuming that Wg=70 mm, as shown in
3-B. Impact of the Width Wg on Antenna Performance
As shown in
Sizes of the exciting element 23 and the ground plane 15 may be determined based on sizes of an overall system model to which the antenna apparatus provided in this application is actually applied. To make the exciting element 23 effectively excite the ground plane 15 to generate radiation, a relative position relationship between the exciting element 23 and the ground plane 15 may be as follows:
1. The exciting element 23 may be parallel to the first side (for example, the lateral side 21-1) of the ground plane 15, or a smaller included angle may be presented between the exciting element 23 and the first side (for example, the lateral side 21-1) of the ground plane 15, the exciting element 23 and the first side of the ground plane 15 may be nearly parallel. The smaller included angle may be less than a first angle, such as 5°. The first angle is not limited to 5°, and may alternatively be an angle such as 3° or 7°. In this case, an included angle α between the exciting element 23 and the first side is less than an included angle β between the exciting element 23 and the third side. Particularly, when the included angle α=0 and the included angle β=90°, the exciting element 23 is parallel to the first side. In this case, the exciting element 23 is more likely to excite the ground plane 15 to generate radiation.
2. The exciting element 23 may be set on the ground plane 15 in proximity to the first side (for example, the lateral side 21-1) of the ground plane 15. Herein, the proximity may mean that a distance between the exciting element 23 and the first side is less than a specific distance, for example, 4 mm. The specific distance is not limited to 4 mm, and may alternatively be a value such as 3 mm, 2 mm, or 1 mm. In this case, a distance L1 from the exciting element 23 to the first side is less than a distance L2 from the exciting element 23 to the second side (for example, the lateral side 21-5). The first side and the second side are two opposite sides of the ground plane 15. L1 may be equal to 0. In this case, the exciting element 23 is set at the first side of the ground plane, and the exciting element 23 is more likely to excite the ground plane 15 to generate radiation. In other words, a closer proximity of the exciting element 23 to the first side indicates that the ground plane 15 is more likely to be excited to generate radiation.
It may be understood that when the exciting element 23 is parallel to the first side, the distance between the exciting element 23 and the first side is unique. When the exciting element 23 is nearly parallel to the first side, the distance between the exciting element 23 and the first side may be a distance from a point (for example, a center point) on the exciting element 23 to the first side, or an average value of a plurality of distances from each of a plurality of points on the exciting element 23 to the first side.
3. A difference between a distance p1 from a first end of the exciting element 23 to a third side (for example, a bottom side 21-7) of the ground plane 15 and a distance p2 from a second end of the exciting element 23 to a fourth side (for example, a top side 21-3) of the ground plane 15 is less than a first value, for example, 15 mm. The first value is not limited to 15 mm, and may alternatively be a value such as 12 mm or 20 mm. In addition to the first side (for example, the lateral side 21-1) and the second side (for example, the lateral side 21-5) that are opposite to each other, the third side and the fourth side are the other two opposite sides of the ground plane 15. The first end of the exciting element 23 is an end close to the third side, and the second end of the exciting element 23 is an end close to the fourth side. When the exciting element 23 is parallel to the first side, p1+p2+Le=Lg; and when the exciting element 23 is not parallel to the first side, and an included angle α (α≠0) exists between the exciting element 23 and the first side, p1+p2+Le>Lg. When the difference between p1 and p2 is 0, the exciting element 23 is more likely to excite the ground plane 15 to generate resonance. In this case, p1 and p2 are equal, and both are equal to (Lg−Le)/2.
The foregoing content describes a design solution of an antenna operating at a single band. The single band may be a 900 MHz low-frequency band, a GPS L5, a GPS L1, or the like. In addition to the single band, the antenna apparatus provided in this application may further implement a dual-band, a wide-band, or a multi-band, and may be implemented by using the matching network or adding more magnetic rings. Details are described below.
Dual-Band Antenna Solution Based on a Matching Network
As shown in
Dual-Band, Wide-Band, or Multi-Band Antenna Solution Based on a Multi-Magnetic Ring
As shown in
The parasitic element may have a same structure as the exciting element 23. The parasitic element may have a third branch and two fourth branches. The third branch is similar to the first branch 29-2 in the exciting element 23, and the fourth branches are similar to the second branches 29-1 and 29-3 in the exciting element 23. Similar to the structure of the exciting element 23, the two fourth branches in the parasitic element may be respectively connected to two ends of the third branch. An end of the fourth branch that is away from the first branch is connected to the ground plane 15. The two fourth branches may be used to set the third branch on the ground plane 15, so that a gap is formed between the third branch and the ground plane 15. Like the exciting element 23, a capacitor may be connected in series on the parasitic element. The capacitor may be referred to as a fifth capacitor. To connect the fifth capacitor in series, a gap may be disposed on the third branch, and the fifth capacitor may be connected in series between two parts of the third branch on both sides of the gap. The gap may be referred to as a second slot.
While the exciting element 23 excites the ground plane 15 to generate radiation, the ground plane 15 couples the parasitic element to generate radiation, thereby implementing dual-band radiation.
To cover more bands or a wider band, more parasitic magnetic rings may be disposed on the ground plane 15, as shown in
In addition to being disposed in proximity to lateral sides of the ground plane 15 shown in
To implement multi input multi output (multi input multi output, MIMO), the antenna apparatus provided in this application may include a plurality of antenna elements. One antenna element may have one exciting element 23, or may have one exciting element 23 and M (M is a positive integer) parasitic elements. The plurality of antenna elements may be disposed in proximity to the sides of the ground plane 15. For example, as shown in
The parasitic element is not limited to the parasitic magnetic ring having the same structure as the exciting element 23. To implement a multi-band or a wide-band, the parasitic element may alternatively be another antenna, such as a support antenna or a floating antenna. The support antenna may include an inverted F antenna (inverted F antenna, IFA), an inverted L antenna (inverted L antenna. ILA), and the like.
In some embodiments, the IFA may also serve as an exciting element, namely, the IFA is fed, and the IFA may couple energy to a magnetic ring having a same structure as the exciting element 23. Then, the magnetic ring may couple energy to the ground plane, to excite the ground plane to generate radiation. In this case, a matching network of the IFA as an exciting element may be that a 1 pF capacitor is first connected in series, and then a 4 nH inductor is connected m parallel. A 0.8 pF capacitor may be connected in series on the magnetic ring as a parasitic element. Similarly, the ILA may also serve as an exciting element, namely, the ILA is fed, and the ILA can couple energy to a magnetic ring having a same structure as the exciting element 23. Then, the magnetic ring may couple energy to the ground plane, to excite the ground plane to generate radiation.
The capacitor and the inductor mentioned in the foregoing content of this application may be implemented by using a lumped element, or may be implemented by using a distributed element.
The foregoing descriptions are merely specific implementations of this application, but are not intended to limit the protection scope of this application. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in this application shall fall within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.
Number | Date | Country | Kind |
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201910146577.6 | Feb 2019 | CN | national |
201910614002.2 | Jul 2019 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2020/074578 | 2/10/2020 | WO | 00 |