Patent Grant
12212055
This application is a national stage of International Application No. PCT/CN2022/089005, filed on Apr. 25, 2022, which claims priority to Chinese Patent Application No. 202110490769.6, filed on May 6, 2021. The disclosures of both of the aforementioned application are hereby incorporated by reference in their entireties.
This application relates to the field of communications technologies, and in particular, to an antenna decoupling structure, a MIMO antenna, and a terminal.
With the development of mobile communications technologies, a terminal notebook computer is required to support more and more frequency bands, and a MIMO (Multiple-Input Multiple-Output) antenna is more and more widely applied to terminal notebook computers. Referring to
To resolve the problem that the isolation between the two IFA antenna units is low, a T-shaped decoupling structure 04 is added between the two IFA antenna units, as shown in
However, as shown in
This application provides an antenna decoupling structure, an antenna, and a terminal, to implement decoupling for a target decoupling frequency band by using a constituted LC resonant structure, implement antenna miniaturization, and increase an isolation between antennas.
According to a first aspect, this application provides an antenna decoupling structure. The antenna decoupling structure includes a grounding stub and a capacitor structure, where a first end of the grounding stub is connected to an antenna floor, to form an equivalent inductor; and a first end of the capacitor structure is connected to the antenna floor, and a second end of the capacitor structure is connected to a second end of the grounding stub, so that the equivalent inductor and the capacitor structure form an LC resonant structure, where a parameter corresponding to the LC resonant structure meets a decoupling requirement for at least one target decoupling frequency band.
In this way, a capacitance of the capacitor structure and an inductance of the equivalent inductor L are adjusted to ensure that a resonant frequency of the LC resonant structure is the same as the target decoupling frequency band, thereby implementing decoupling for the target decoupling frequency band. Because the resonant frequency depends on the inductance and the capacitance that correspond to the LC resonant structure, antenna miniaturization can be realized by reducing a size of each portion of the decoupling structure. Different resonant modes can be formed by adjusting the parameter corresponding to the LC resonant structure, thereby meeting decoupling requirements for different target decoupling frequency bands.
In an implementation, the antenna decoupling structure provided in this application further includes a first decoupling stub and a second decoupling stub, where the first decoupling stub and the second decoupling stub are respectively disposed on two sides of the grounding stub; a first end of the first decoupling stub is connected to the second end of the grounding stub, and a length of the first decoupling stub meets a decoupling requirement for a second target decoupling frequency band; and a first end of the second decoupling stub is connected to the second end of the grounding stub, and a length of the second decoupling stub meets a decoupling requirement for a third target decoupling frequency band, where the parameter corresponding to the LC resonant structure meets a decoupling requirement for a first target decoupling frequency band, and the first target decoupling frequency band is a lowest frequency band among the first target decoupling frequency band, the second target decoupling frequency band, and the third target decoupling frequency band.
In this way, decoupling for three frequency bands can be implemented by using the LC resonant structure, the first decoupling stub, and the second decoupling stub, respectively, thereby implementing decoupling for a plurality of operating frequency bands.
In an implementation, the length of the first decoupling stub is a quarter of a wavelength corresponding to a center frequency of the second target decoupling frequency band; the length of the second decoupling stub is a quarter of a wavelength corresponding to a center frequency of the third target decoupling frequency band; and an open end formed after bending of the first decoupling stub is disposed opposite to an open end formed after bending of the second decoupling stub.
In this way, the lengths of the first decoupling stub and the second decoupling stub meet the decoupling requirements for the target decoupling frequency bands; and miniaturization is guaranteed. As the open end formed after bending of the first decoupling stub is disposed opposite to the open end formed after bending of the second decoupling stub, space occupied by the first decoupling stub and the second decoupling stub can be further reduced.
In an implementation, the capacitor structure uses a lumped parameter capacitor.
In this way, convenience is brought for implementing miniaturization of the decoupling structure because a size of the lumped parameter capacitor is small.
In an implementation, the capacitor structure is formed by coupling a capacitive coupling stub to the grounding stub that is disposed opposite to a first end of the capacitive coupling stub at an interval, and a second end of the capacitive coupling stub is connected to the antenna floor.
In this way, structures of the capacitive coupling stub and the grounding stub are coupled to form a required capacitor structure, so that a small quantity of components can be added outside the coupled structure.
In an implementation, a plurality of coupling slots are formed between the first end of the capacitive coupling stub and the first end of the grounding stub.
In this way, the plurality of coupling slots are formed between the first end of the capacitive coupling stub and the first end of the grounding stub, which increases a coupling area, and a capacitance of the capacitor structure.
In an implementation, the grounding stub includes a first grounding sub-stub and a second grounding sub-stub that are disposed in an L-shaped form, a first end of the first grounding sub-stub is perpendicularly connected to the antenna floor, a second end of the first grounding sub-stub is perpendicularly connected to a first end of the second grounding sub-stub, and a first groove is formed in a side, facing the antenna floor, of the second grounding sub-stub; and the capacitive coupling stub includes a first capacitive coupling sub-stub and a second capacitive coupling sub-stub that are disposed in a T-shaped form, a first end of the first capacitive coupling sub-stub is disposed in the first groove and opposite to the first groove at an interval, a second end of the first capacitive coupling sub-stub is perpendicularly connected to the antenna floor, a first end of the second capacitive coupling sub-stub is perpendicularly connected to the first capacitive coupling sub-stub, and the second capacitive coupling sub-stub is disposed opposite to a second end of the second grounding sub-stub at an interval.
In this way, the first groove is formed in the grounding stub, and a structure of the capacitive coupling stub is designed to T-shaped to match the first groove, so that the plurality of coupling slots are formed between the capacitive coupling stub and the grounding stub, which increases a capacitance of the coupling capacitor.
In an implementation, the grounding stub includes a first grounding sub-stub, a second grounding sub-stub, and a third grounding sub-stub, a first end of the first grounding sub-stub is perpendicularly connected to the antenna floor, a second end of the first grounding sub-stub is perpendicularly connected to a first end of the second grounding sub-stub, a second end of the second grounding sub-stub is perpendicularly connected to a first end of the third grounding sub-stub, and a second end of the third grounding sub-stub faces the antenna floor; and the capacitive coupling stub includes a third capacitive coupling sub-stub and a fourth capacitive coupling sub-stub, a first end of the third capacitive coupling sub-stub is perpendicularly connected to the antenna floor, a second end of the third capacitive coupling sub-stub is perpendicularly connected to the fourth capacitive coupling sub-stub, a second groove is formed in a side, away from the antenna floor, of the fourth capacitive coupling sub-stub, and the second end of the third grounding sub-stub is disposed in the second groove and opposite to the second groove at an interval.
In this way, the second groove is formed in the capacitive coupling stub, and the third grounding sub-stub disposed opposite to the second groove at an interval is designed on the grounding stub in a matching manner, so that the plurality of coupling slots are formed between the capacitive coupling stub and the grounding stub, which increases a capacitance of the coupling capacitor.
In an implementation, the first target decoupling frequency band ranges from 2.49 GHz to 2.69 GHz, the second target decoupling frequency band ranges from 3.3 GHz to 3.8 GHz, and the third target decoupling frequency band ranges from 4.4 GHz to 5 GHz; the grounding stub includes a first grounding sub-stub, a second grounding sub-stub, and a third grounding sub-stub, a first end of the first grounding sub-stub is perpendicularly connected to the antenna floor, a second end of the first grounding sub-stub is perpendicularly connected to a first end of the second grounding sub-stub, a second end of the second grounding sub-stub is perpendicularly connected to a first end of the third grounding sub-stub, and a second end of the third grounding sub-stub faces the antenna floor; the capacitive coupling stub includes a third capacitive coupling sub-stub and a fourth capacitive coupling sub-stub, a first end of the third capacitive coupling sub-stub is perpendicularly connected to the antenna floor, a second end of the third capacitive coupling sub-stub is perpendicularly connected to the fourth capacitive coupling sub-stub, a second groove is formed in a side, away from the antenna floor, of the fourth capacitive coupling sub-stub, and the second end of the third grounding sub-stub is disposed in the second groove and opposite to the second groove at an interval; a shortest horizontal distance between a first side edge of the first grounding sub-stub and the fourth capacitive coupling sub-stub is 7.3 mm, a shortest horizontal distance between a second side edge of the first grounding sub-stub and the fourth capacitive coupling sub-stub is 8.5 mm, a distance between the antenna floor and a first side edge of the second grounding sub-stub is 2.8 mm, and a distance between the antenna floor and a second side edge of the second grounding sub-stub is 3.8 mm; the first end of the first decoupling stub and the second end of the second grounding sub-stub are connected to each other and form a first connection point, and the first decoupling stub extends from the first connection point in a direction away from the antenna floor by 1 mm, in a direction parallel to the antenna floor and away from the third capacitive coupling sub-stub by 11.5 mm, in a direction away from the antenna floor by 3.7 mm, and in a direction parallel to the antenna floor and close to the third capacitive coupling sub-stub by 7 mm, sequentially; and an open end of the second decoupling stub is disposed opposite to an open end of the first decoupling stub, and the second decoupling stub extends from the open end in a direction away from the first decoupling stub by 5 mm, in a direction close to the antenna floor by 2.5 mm, in a direction close to the first decoupling stub by 3.5 mm, and in a direction close to and perpendicular to the antenna floor, sequentially, and is then connected to the first connection point.
In this way, the antenna decoupling structure can be applied to an NR antenna, to implement decoupling for operating frequency bands of the NR antenna.
According to a second aspect, this application provides a MIMO antenna. The MIMO antenna includes a first antenna unit, a second antenna unit, and the antenna decoupling structure according to the first aspect, where the antenna decoupling structure is disposed at a preset location between the first antenna unit and the second antenna unit, and is configured to increase an isolation between the first antenna unit and the second antenna unit.
In this way, different resonant modes can be formed by adjusting the parameter corresponding to the LC resonant structure, thereby implementing decoupling for different operating frequency bands of the first antenna unit and the second antenna unit.
In an implementation, the first antenna unit includes a feed stub, a floor stub, and a first radiation stub, where the floor stub includes a first floor sub-stub and a second floor sub-stub; a first end of the first floor sub-stub is connected to the antenna floor; a second end of the first floor sub-stub is connected to a first end of the second floor sub-stub; a second end of the second floor sub-stub is disposed opposite to the feed stub at an interval, to form a coupling capacitor; the floor stub and the feed stub form a left-handed antenna mode, and a parameter corresponding to the left-handed antenna mode meets a frequency requirement for the first antenna unit at a first operating frequency band; the second end of the second floor sub-stub is connected to the first radiation stub, the first radiation stub and the feed stub form a first monopole antenna mode, and a parameter corresponding to the first monopole antenna mode meets a frequency requirement for the first antenna unit at a second operating frequency band; and the first operating frequency band is less than the second operating frequency band.
In this way, the feed stub, the floor stub, and the first radiation stub constitute the two antenna modes: the left-handed antenna mode and the first monopole antenna mode that can resonate with different frequencies. A resonant frequency of a left-handed antenna depends on an inductance and a capacitance. Compared with a length of an IFA antenna, a monopole antenna, or another antenna that can be as small as a quarter of a wavelength, a length of the left-handed antenna can be as small as one eighth of the wavelength. Therefore, a size of the first antenna unit can be further reduced.
In an implementation, the first antenna unit further includes a second radiation stub, where the second radiation stub and the first radiation stub are respectively disposed on two sides of the floor stub, a first end of the second radiation stub is connected to the first end of the second floor sub-stub, the first radiation stub, the second floor sub-stub, the second radiation stub, and the feed stub form a balanced antenna mode, and a parameter corresponding to the balanced antenna mode meets a frequency requirement for the first antenna unit at a third operating frequency band; the second radiation stub, the second floor sub-stub, and the feed stub form a second monopole antenna mode, and a parameter corresponding to the second monopole antenna mode meets a frequency requirement for the first antenna unit at a fourth operating frequency band; and the first operating frequency band is less than the fourth operating frequency band, the fourth operating frequency band is less than the third operating frequency band, and the third operating frequency band is less than the second operating frequency band.
In this way, the feed stub, the floor stub, the first radiation stub, and the second radiation stub constitute the four antenna modes: the left-handed antenna mode, the first monopole antenna mode, the second monopole antenna mode, and the balanced antenna mode that can resonate with different frequencies, so that the first antenna unit can cover more operating frequency bands.
In an implementation, the floor stub further includes a third floor sub-stub, a first end of the third floor sub-stub is perpendicularly connected to the second end of the second floor sub-stub, a third groove is formed in a side, away from the antenna floor, of the feed stub, and a second end of the third floor sub-stub is disposed in the third groove and opposite to the third groove at an interval; and the second radiation stub includes a horizontal radiation stub and a vertical radiation stub, a first end of the horizontal radiation stub is connected to the first end of the second floor sub-stub, a second end of the horizontal radiation stub is connected to a first end of the vertical radiation stub, and a second end of the vertical radiation stub faces the antenna floor.
In this way, the second radiation stub is bent, so that a horizontal dimension of the antenna unit can be further reduced.
In an implementation, the MIMO antenna is used as a WIFI MIMO tri-band antenna, where operating frequency bands of the WIFI MIMO tri-band antenna are 2.4 GHz to 2.5 GHz, 5.1 GHz to 5.8 GHz, and 5.9 GHz to 7.1 GHz, respectively; a shortest horizontal distance between the first floor sub-stub and the third floor sub-stub is 6 mm, a distance between a first side edge of the second floor sub-stub and the antenna floor is 4.5 mm, a distance between a second side edge of the second floor sub-stub and the antenna floor is 7.5 mm, a distance between a first side edge of the first radiation stub and a second side edge of the first radiation stub is 3 mm, a distance between a second end of the first radiation stub and a first side edge of the first floor sub-stub is 11.2 mm, a distance between the second end of the first radiation stub and the second end of the horizontal radiation stub is 16 mm, a distance between a first side edge of the vertical radiation stub and a first side edge of the horizontal radiation stub is 2 mm, a distance between the first side edge of the vertical radiation stub and a second side edge of the horizontal radiation stub is 3 mm, and a distance between the first side edge of the horizontal radiation stub and the antenna floor is 6 mm; and the third groove is 4.14 mm wide and 2.3 mm high, and an opening of the third groove is 2.14 mm wide.
In this way, the antenna unit can cover the operating frequency bands of the WIFI MIMO tri-band antenna.
In an implementation, the MIMO antenna is used as an NR antenna, where operating frequency bands of the NR antenna are 2.49 GHz to 2.69 GHz, 3.3 GHz to 3.8 GHz, and 4.4 GHz to 5 GHz, respectively; the first floor sub-stub extends from the first end of the first floor sub-stub in a direction away from the antenna floor by 5.5 mm and in a direction parallel to the antenna floor by a first preset distance, sequentially, and is connected to the first end of the second floor sub-stub; a distance between a first side edge and a second side edge of the first radiation stub is 3 mm, a shortest distance between a second end of the first radiation stub and the third groove is 3.9 mm, a distance between a second end of the first radiation stub and the second end of the horizontal radiation stub is 20.2 mm, and a distance between a first side edge and a second side edge of the vertical radiation stub is 4.5 mm; and the third groove is 4.1 mm wide and 2.8 mm high.
In this way, the antenna unit can cover the operating frequency bands of the NR antenna.
In an implementation, a structure of the first antenna unit is the same as that of the second antenna unit.
In this way, both the first antenna unit and the second antenna unit have antenna structures of the left-handed antenna mode and the first monopole antenna mode, or have antenna structures of the left-handed antenna mode, the first monopole antenna mode, the second monopole antenna mode, and the balanced antenna mode, so that both the first antenna unit and the second antenna unit have more operating frequency bands, and a total size of an antenna can be reduced.
According to a third aspect, this application provides a terminal, including the MIMO antenna according to the second aspect.
In this way, a development trend towards a greater screen-to-body ratio of a terminal product can be met.
Reference numerals in the accompanying drawings are as follows:
01: first feed point, 02: second feed point, 03: antenna floor, 04: T-shaped decoupling structure;
1: first antenna unit, 2: second antenna unit, 3: antenna decoupling structure, 4: antenna floor, 5: dielectric substrate; 10: first feed point, 11: feed stub, 12: floor stub, 13: first radiation stub, 14: second radiation stub, 20: second feed point, 31A: lumped parameter capacitor, 31B: capacitive coupling stub, 32: grounding stub, 33: first decoupling stub, 34: second decoupling stub; 111: third groove, 121: first floor sub-stub, 122: second floor sub-stub, 123: third floor sub-stub, 141: horizontal radiation stub, 142: vertical radiation stub, 31B1: first capacitive coupling sub-stub, 31B2: second capacitive coupling sub-stub, 31B3: third capacitive coupling sub-stub, 31B4: fourth capacitive coupling sub-stub, 31B5: second groove, 321: first grounding sub-stub, 322: second grounding sub-stub, 323: first groove; 324: third grounding sub-stub.
The technical solutions of the embodiments of the present invention are clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely some rather than all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
For ease of understanding of the technical solutions of this application, the following briefly describes a concept: an isolation of an antenna.
“Isolation” (isolation) is a ratio of a transmit power of an antenna unit to a received power of another antenna unit, where a unit of the ratio may be dB. An isolation of an antenna is used to quantitatively represent a strength of coupling between antenna units. The unit of the isolation may be dB. A logarithm, to a base of 10, of a ratio of a transmit power to a received power, namely, lg, is used to represent a value of the isolation whose counting unit is dB. A greater value of the isolation indicates a smaller degree of interference between two antenna units. A MIMO antenna, having characteristics such as a high channel capacity and high channel reliability, is more and more widely applied to various wireless communications systems. However, antenna units of an antenna are adjacent to each other because accommodating space of the antenna is limited. As a result, an isolation of the antenna is low. Especially, when two antenna units of the antenna are at a same operating frequency band, a coupling function between the antenna units is serious, and an isolation of the antenna is greatly decreased.
To increase the isolation of the antenna, in an implementation, a T-shaped decoupling structure may be added between the two antenna units.
Because a length of the IFA antenna unit is related to a frequency, a higher frequency indicates a shorter wavelength and a shorter length of the IFA antenna unit; and a lower frequency indicates a longer wavelength and a longer length of the IFA antenna unit. For example, the IFA antenna unit in
This application provides a MIMO antenna, to resolve a problem that a dimension of an antenna cannot meet a requirement for miniaturization of the antenna. The following describes a structure of the MIMO antenna in this embodiment of this application with reference to the accompanying drawings.
First, the antenna decoupling structure of the MIMO antenna is described below.
In this embodiment of this application, a capacitance of the capacitor structure and an inductance of the equivalent inductor L are adjusted to ensure that a resonant frequency of the LC resonant structure is the same as the target decoupling frequency band, thereby implementing decoupling. The antenna decoupling structure 3 in this embodiment of this application mainly includes the capacitor structure and the grounding stub 32 that is used for forming the equivalent inductor L. To reduce a size of the antenna decoupling structure 3, that is, shorten a coupling path of a current, it needs to be ensured that a size of the grounding stub 32 is as small as possible. Then, the capacitance is adjusted according to a relationship between a resonant frequency, and an inductance and a capacitance, to ensure that the resonant frequency of the LC resonant structure is the same as the target decoupling frequency band. A specific shape and size of the antenna decoupling structure 3 in this embodiment of this application may be determined through simulation and experiments according to a decoupling requirement for the target decoupling frequency band.
The capacitor structure is not limited in this embodiment of this application. In an implementation, as shown in
In an implementation, the capacitor structure may be that shown in
In another implementation, the capacitor structure may be that shown in
Because a resonant frequency of the antenna decoupling structure provided in this embodiment of this application depends on the inductance and the capacitance that correspond to the LC resonant structure, antenna miniaturization can be realized by reducing a size of each portion of the decoupling structure.
Decoupling for two frequency bands 2.4 GHz and 5 GHz is used as an example. A horizontal length d2 of the antenna decoupling structure 3 in
Structures of the first antenna unit 1 and the second antenna unit 2 are not limited in this embodiment of this application. For example, the first antenna unit 1 may be an IFA antenna, a PIFA antenna, a left-handed antenna, or the like; and a structure of the second antenna unit 2 may be the same as or different from that of the first antenna unit 1.
Operating frequency bands of the first antenna unit 1 and the second antenna unit 2 are not limited in this application. The first antenna unit 1 and the second antenna unit 2 may have at least one same operating frequency band. For example, if operating frequency bands of the first antenna unit 1 are 2.4 GHz and 3.8 GHz, and operating frequency bands of the second antenna unit 2 are 2.4 GHz and 5 GHz, the first antenna unit 1 and the second antenna unit 2 have one same operating frequency band: 2.4 GHz. For another example, if operating frequency bands of the first antenna unit 1 are 2.4 GHz and 5 GHz, and operating frequency bands of the second antenna unit 2 are 2.4 GHz and 5 GHz, the first antenna unit 1 and the second antenna unit 2 have two same operating frequency bands: 2.4 GHz and 5 GHz, that are two common operating frequency bands of existing WIFI antennas.
A target decoupling frequency band of the antenna decoupling structure 3 is not limited in this embodiment of this application. For example, the antenna decoupling structure 3 may be configured to implement decoupling for any one or two of frequency bands: 2.4 GHz, 3.8 GHz, and 5 GHz. In other words, the antenna decoupling structure 3 in this embodiment of this application can decouple a single-band antenna or a dual-band antenna. If the antenna decoupling structure 3 is configured to decouple a single-band antenna, that is, the first antenna unit 1 and the second antenna unit 2 have a same operating frequency band, parameters corresponding to the antenna decoupling structure 3 (these parameters include a shape and a size of the grounding stub, a capacitance of the capacitor structure, and the like) can resonate with a frequency that is the same as the target decoupling frequency band. If the antenna decoupling structure 3 is configured to decouple a dual-band antenna, that is, the first antenna unit 1 and the second antenna unit 2 have two same operating frequency bands, the parameters corresponding to the antenna decoupling structure 3 can form two resonant modes. The two resonant modes can respectively resonate with frequencies that are the same as the two target decoupling frequency bands.
The following further describes the MIMO antenna having the antenna decoupling structure 3 capable of decoupling two frequency bands: 2.4 GHz and 5.5 GHz.
As shown in
In this embodiment of this application, the antenna decoupling structure 3 capable of decoupling a 2.4 GHz and 5.5 GHz dual-band antenna is determined through simulation and experiments. As shown in
Still referring to
In summary, all of the radiation efficiency, the system efficiency, and the isolation of the MIMO antenna provided in the foregoing embodiment of this application are satisfactory. In addition, the horizontal dimension d2 of the antenna decoupling structure 3 is 20 mm shorter than that of the T-shaped decoupling structure 04.
An embodiment of this application further provides a structure of an antenna unit. The structure of the antenna unit may be the first antenna unit in the foregoing embodiment.
As shown in
It can be ensured, by adjusting shapes and sizes of the floor stub 12 and the feed stub 11 and performing determining with reference to simulation and experiments, that the parameter corresponding to the left-handed antenna mode meets a communications requirement for the first antenna unit at the first operating frequency band. For details about the left-handed antenna mode, refer to description of the LC resonant structure in the foregoing embodiment. In the left-handed antenna mode, a feed point is connected to a capacitor in series and then connected to a radiator for radiation. Owing to existence of a distributed capacitor, a resonant frequency of the left-handed antenna mode depends on an equivalent inductance and capacitance of the composite structure, so that the left-handed antenna mode has a small size. A difference between the left-handed antenna mode and the LC resonant structure lies in that resonance of the left-handed antenna mode is directly excited by the first feed point 10 of the first antenna unit 1, but resonance of the LC resonant structure is indirectly excited by exciting a current generated by the first feed point 10 to flow through the antenna floor. A structure of the coupling capacitor formed in the left-handed antenna mode is not limited in this application. For details, refer to the capacitor structure of the LC resonant structure in the foregoing embodiment.
A resonant frequency of a left-handed antenna depends on an inductance and a capacitance. Compared with a length of an IFA antenna, a monopole antenna, or another antenna that can be as small as a quarter of a wavelength, a length of the left-handed antenna can be as small as one eighth of the wavelength. Therefore, a size of the first antenna unit 1 can be further reduced. The first monopole antenna mode of the first antenna unit 1 includes the feed stub 11 and the first radiation stub 13. The second end of the second floor sub-stub 122 is connected to the first radiation stub 13, the first radiation stub 13 and the feed stub 11 form a first monopole antenna mode, and a parameter corresponding to the first monopole antenna mode meets a frequency requirement for the first antenna unit 1 at a second operating frequency band. The second operating frequency band may be different from the first operating frequency band, and may be any one of the following operating frequency bands: 2.4 GHz, 3.8 GHz, 5.5 GHz, 6.2 GHz, 7.1 GHz, and the like. This is not limited in this embodiment of this application.
Transmit-to-received conversion efficiency of the antenna is highest when the length of the antenna is a quarter of a wavelength of a radio signal. Therefore, a best length of the first radiation stub 13 in the first monopole antenna mode can be obtained by calculating a wavelength based on a center transmit frequency and a center received frequency, namely, a center frequency of the second operating frequency band of the first antenna unit and dividing the wavelength by 4. For example, if the center frequency of the second operating frequency band is 2.4 GHz, a wavelength λ corresponding to 2.4 GHz can be calculated according to a relational expression v=fλ between a frequency f and the wavelength λ. Further, it can be calculated that a length of the first radiation stub 13 is λ/4.
It can be learned that a lower frequency corresponds to a greater length of the first radiation stub 13. Therefore, to reduce the size of the first antenna unit 1, the left-handed antenna in the first antenna unit 1 should be configured to resonant with a low frequency, and the first monopole antenna mode should be configured to resonant with a low frequency.
For example, the first operating frequency band is 2.5 GHz, and the second operating frequency band is 5 GHz. As shown in
In this way, the antenna unit can cover more operating frequency bands. An embodiment of this application provides another structure of an antenna unit. The structure of the antenna unit may be the first antenna unit in the foregoing embodiment.
The feed stub 11, the floor stub 12, the first radiation stub 13, and the second radiation stub 14 of the first antenna unit 1 in
As shown in
The first radiation stub 13, the second floor sub-stub 122, the second radiation stub 14, and the feed stub 11 form the balanced antenna mode. A parameter corresponding to the balanced antenna mode meets a frequency requirement for the first antenna unit 1 at a third operating frequency band. The third operating frequency band may be any one of the following frequency bands: 2.4 GHz, 3.8 GHz, 5.5 GHz, 6.2 GHz, 7.1 GHz, and the like. This is not limited in this embodiment of this application.
The second radiation stub 14, the second floor sub-stub 122, and the feed stub 11 form the second monopole antenna mode. The second radiation stub 14 may be bent to reduce horizontal space occupied by the second radiation stub 14. For example, as shown in
A length of the first radiation stub 13 may be a quarter of a wavelength corresponding to a center frequency of the second operating frequency band. A total length of the second radiation stub and the second floor sub-stub 122 may be a quarter of a wavelength corresponding to the fourth operating frequency band. A total length of the first radiation stub 13, the second floor sub-stub 122, and the second radiation stub 14 may be a half of a wavelength corresponding to the third operating frequency band. To implement size minimization of the first antenna unit 1, the first operating frequency band is less than the fourth operating frequency band, the fourth operating frequency band is less than the third operating frequency band, and the third operating frequency band is less than the second operating frequency band. For example, the first operating frequency band is 2.5 GHz, the second operating frequency band is 7.1 GHz, the third operating frequency band is 6.2 GHz, and the fourth operating frequency band is 5 GHz.
In summary, the first antenna unit provided in the foregoing embodiment of this application can cover a plurality of operating frequency bands by constituting a plurality of antenna modes. Therefore, the foregoing antenna unit can be applied to a WIFI MIMO tri-band antenna or an NR antenna. Operating frequency bands of the WIFI MIMO tri-band antenna are 2.4 GHz to 2.5 GHz, 5.1 GHz to 5.8 GHz, and 5.9 GHz to 7.1 GHz, respectively. Operating frequency bands of the NR antenna are 2.49 GHz to 2.69 GHz, 3.3 GHz to 3.8 GHz, and 4.4 GHz to 5 GHz, respectively.
The following describes scenarios in which the foregoing first antenna unit is applied to the WIFI MIMO tri-band antenna and the NR antenna, respectively.
The scenario in which the foregoing first antenna unit is applied to the WIFI MIMO tri-band antenna is shown in
It can be learned, from
It can be learned, from curves of return losses in
Another antenna decoupling structure is described before the scenario in which the foregoing antenna unit is applied to the NR antenna. The antenna decoupling structure 3 can decouple more operating frequency bands, thereby matching the foregoing antenna unit and being applied to the NR antenna.
The antenna decoupling structure 3 provided in this embodiment of this application is substantially the same as the antenna decoupling structure 3 provided in the foregoing embodiments. A difference between the two structures is that the antenna decoupling structure 3 provided in this embodiment of this application is additionally provided with a first decoupling stub 33 and a second decoupling stub 34.
As shown in
According to the antenna decoupling structure 3 in
The antenna decoupling structure 3 in
It should be understood that the antenna decoupling structure 3 in
For example, the foregoing antenna decoupling structure and antenna unit are jointly applied to the NR antenna, that is, the first target decoupling frequency band is 2.5 GHz, the second target decoupling frequency band is 3.8 GHz, and the third target decoupling frequency band is 5.5 GHz. As shown in
For example, the foregoing antenna decoupling structure and antenna unit are jointly applied to the NR antenna. According to the MIMO antenna in
Still referring to
It can be learned, from
In summary, according to the antenna provided in this embodiment of this application, the total horizontal length of the antenna can be reduced, so that antenna miniaturization is realized, and decoupling can be implemented at more frequency bands.
Referring to FIG.
As shown in
As shown in
A shortest horizontal distance c1 between a first side edge of the first grounding sub-stub 321 and the fourth capacitive coupling sub-stub 31B4 is 7.3 mm, and a shortest horizontal distance c2 between a second side edge of the first grounding sub-stub 321 and the fourth capacitive coupling sub-stub 31B4 is 8.5 mm. The first side edge of the first grounding sub-stub 321 is a side edge perpendicular to the antenna floor 4 and close to the fourth capacitive coupling sub-stub 31B4. The second side edge of the first grounding sub-stub 321 is a side edge perpendicular to the antenna floor 4 and away from the fourth capacitive coupling sub-stub 31B4. A distance c3 between the antenna floor 4 and a first side edge of the second grounding sub-stub 322 is 2.8 mm. A distance c4 between the antenna floor 4 and a second side edge of the second grounding sub-stub 322 is 3.8 mm. The first side edge of the second grounding sub-stub 322 is a side edge parallel to and close to the antenna floor 4. The second side edge of the second grounding sub-stub 322 is a side edge parallel to and away from the antenna floor 4.
For example, the length of the first decoupling stub 33 may be a quarter of a wavelength corresponding to a center frequency of the second target decoupling frequency band; and the length of the second decoupling stub 34 may be a quarter of a wavelength corresponding to a center frequency of the third target decoupling frequency band. However, the first decoupling stub 33 and the second decoupling stub 34 may be bent for a plurality of times, to reduce horizontal space occupied by the first decoupling stub 33 and the second decoupling stub 34.
In an implementation, as shown in
The antenna decoupling structure and the MIMO antenna provided in the embodiments of this application may be applied to a terminal. The terminal may be any device having a wireless communication function, such as a personal computer, a tablet computer, or a mobile phone. This is not limited in this application. For example, the MIMO antenna in
An implementation process of the antenna decoupling structure and the antenna is not limited in the embodiments of this application. For example, the process may be printing using a printed circuit board (printed circuit board, PCB) or a flexible printed circuit (flexible printed circuit, FPC) or forming through laser-direct-structuring (laser-direct-structuring, LDS).
The objectives, technical solutions, and beneficial effects of the present invention are further described in detail in the foregoing specific implementations. It should be understood that the foregoing descriptions are merely specific implementations of the present invention, but are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, or improvement made on the basis of the technical solutions of the present invention shall fall within the protection scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202110490769.6 | May 2021 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/089005 | 4/25/2022 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2022/233248 | 11/10/2022 | WO | A |
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