WO2022145699A1

WO2022145699A1 - Radiating antenna and radiating element thereof

Info

Publication number: WO2022145699A1
Application number: PCT/KR2021/016247
Authority: WO
Inventors: Aiguo Wu; Zhuo Chen; Fuwen HONG; Cheng DENG; Mengting QIU
Original assignee: Samsung Electronics Co., Ltd.
Priority date: 2020-12-28
Filing date: 2021-11-09
Publication date: 2022-07-07
Also published as: CN114696089A

Abstract

Embodiments of the present disclosure provide a radiating element of an antenna, the radiating element includes: an oscillator radiation circuit board on which oscillator radiation arms arranged in pairs are printed; a pair of oscillator balun circuit boards which are configured to support the oscillator radiation circuit board and on which oscillator baluns are printed; the pair of oscillator balun circuit boards are mutually perpendicularly crossed to form oscillators vertical to each other in two directions of polarization; each of the oscillator baluns is provided with two slots extending along the horizontal direction, and the two slots are arranged at intervals in parallel along the height direction to form loading stubs extending along the horizontal direction between the two slots. The present disclosure aims at providing a low-profile radiating antenna and a radiating element thereof to form heteropolarization isolation by being short-circuited the loading stubs connected in parallel through double slots, thereby maintaining the bandwidth and performance of the radiating element while reducing the size.

Description

RADIATING ANTENNA AND RADIATING ELEMENT THEREOF

The present disclosure relates to the field of antenna equipment, and in particular to a radiating antenna and a radiating element thereof.

An antenna oscillator is the most widely used form in the base station antenna field, accounting for more than 80% of the base station. The existing antenna oscillator mostly includes the following forms: patch oscillator arrays, dipole oscillators, differential patch antennas, slot antennas and the like. Wherein the radiating body (also called "oscillator") used in the radiating element of the existing Dipole antenna includes an oscillator radiation arm, a feed network and a balun; and a theoretical height of the balun is generally set to a quarter wavelength; therefore, the oscillator has a large volume.

The patch oscillator is small in its antenna size and is easy to open mould, but has poor radiation efficiency and isolation due to its size. Therefore, the patch oscillator needs to be additionally provided with a reflective board, a differential feed network or a boundary condition to improve the isolation and radiation efficiency; accordingly, the assembly process and the cost are increased. The differential patch antenna improves the isolation of the patch antenna through a differential feed network, and can remove the isolation boundary; but the bandwidth and the tracking index of the antenna get weak and the loss is increased simultaneously.

The dipole antenna has excellent overall performances, but its performance is greatly affected by the size; when the size is reduced, it often fails to maintain the inherent bandwidth and performances.

The slot antenna has the advantages of low profile and small size of the patch antenna; but due to its narrow bandwidth and low radiation efficiency, it is rarely used in a base station antenna.

Thus, it can be seen that the existing various kinds of antenna oscillators cannot simultaneously solve the problems of large size, narrow bandwidth and poor isolation, and thus cannot meet the requirements of 5G-MIMO (fifth generation wireless systems-Multiple-Input Multiple-Output antenna).

In view of this, the present disclosure aims at providing a radiating antenna and a radiating element thereof, which improve the bandwidth and heteropolarization isolation by designing double slots on baluns and being open/short-circuited loading stubs connected in parallel on the baluns, thereby maintaining the bandwidth and performance of the radiating element while reducing the size.

The present disclosure aims at providing a radiating antenna and a radiating element thereof to form heteropolarization isolation by being short-circuited the loading stubs connected in parallel, thereby maintaining the bandwidth and performance of the radiating element while reducing the size.

An embodiment of the present disclosure provides a radiating element of an antenna, characterized in that the radiating element comprises: an oscillator radiation circuit board, on which oscillator radiation arms arranged in pairs are printed; and a pair of oscillator balun circuit boards, configured to support the oscillator radiation circuit board, on which oscillator baluns are printed, wherein the pair of oscillator balun circuit boards are mutually perpendicularly crossed to form oscillators vertical to each other in two directions of polarization; wherein each of the oscillator baluns is provided with two slots extending along the horizontal direction, and the two slots are arranged at intervals in parallel along the height direction to form loading stubs extending along the horizontal direction between the two slots.

In one embodiment, each of the loading stubs comprises a first loading stub, wherein end portions of the first loading stub of the pair of oscillator balun circuit boards are short-circuited so as to form heteropolarization isolation.

In one embodiment, each of the loading stubs further comprises a second loading stub; the first loading stub and the second loading stub respectively extend horizontally from both ends of the oscillator balun circuit board towards a midline of the oscillator balun circuit board; and end portions of the first loading stub and the second loading stub are arranged at intervals. In one embodiment, end portions of the second loading stub of the pair of oscillator balun circuit boards are open-circuited and connected in parallel.

In one embodiment, the second loading stub has a length of 1/8 wavelength.

In one embodiment, each of the oscillator baluns further comprises: a feed circuit; and a parasitic feed circuit adjacent to at least a portion of the feed circuit for coupling with the feed circuit.

In one embodiment, the parasitic feed circuit comprises a first parasitic stub and a second parasitic stub arranged in parallel; the first parasitic stub and the second parasitic stub are arranged along the height direction of the oscillator balun circuit board, and top ends thereof are connected in one piece.

In one embodiment, bottom ends of the first parasitic stub and the second parasitic stub share a same bottom surface with the oscillator balun circuit board; and at least one of the first parasitic stub and the second parasitic stub is grounded by a bottom end thereof.

In one embodiment, the feed circuit comprises a first feed stub arranged along the height direction of the oscillator balun circuit board and a second feed stub bent inwards from a top end of the first feed stub; and the parasitic feed circuit is disposed outside the first feed stub.

Another embodiment of the present disclosure further provides a radiating antenna comprising a plurality of the radiating elements described above, wherein the radiating elements are arranged on a substrate at intervals; and no dividing wall is arranged between adjacent radiating elements.

Based on the above technical solution, it can be seen that in this embodiment, two slots extending along the horizontal direction are formed on the oscillator baluns; and such a double-slot loading structure can form a loading stub extending along the horizontal direction between the two slots; loading stubs on the two oscillator baluns (two directions of polarization) are connected in parallel. In this embodiment, two loading stubs connected in parallel are short-circuited to form a high impedance equivalent to a quarter wavelength, thus suppressing the scattered field caused by low profile mismatch, and achieving the purpose of improving the heteropolarization isolation of the antenna.

In this embodiment, slots are combined with the short-circuited loading stubs by the radiating element to solve the problems of poor bandwidth and performance caused by size reduction through parallel loading and polarization short circuit. In the embodiment, the heteropolarization isolation of the antenna is realized through the short-circuited loading stubs; and it is unnecessary to additionally arrange a separation barrier and a reflective board between adjacent radiating elements, thus achieving the advantages of reducing process and material cost, lowering mould opening difficulty and improving consistency.

The following drawings are merely used to schematically illustrate and explain the present disclosure and are not intended to limit the scope of the present disclosure.

Fig. 1 is a schematic diagram illustrating a structure of a radiating element in a first embodiment of the present disclosure.

Fig. 2 is a schematic diagram illustrating a structure of an oscillator balun circuit board in Fig. 1.

Fig. 3 is a graph comparing the isolation curve of whether the loading stubs of the antennas of the radiating elements in Figs. 1 and 2 are short-circuited.

Figs. 4 and 5 are schematic diagrams illustrating structures of a radiating element in a second embodiment of the present disclosure.

Fig. 6 is a schematic diagram illustrating a structure of an oscillator balun circuit board in Fig. 4.

Fig. 7 is a graph comparing the antenna return loss curve S11 and the insertion loss curve S21 of the radiating element in Figs. 4 and 5.

Fig. 8 is a schematic diagram illustrating a structure of an oscillator balun circuit board in a third embodiment of a radiating element in the present disclosure.

In order to understand the technical features, objective, and effects of the present disclosure more clearly, the embodiments of present disclosure will be described in detail with reference to the accompanying drawings; and the same reference numeral refers to the same portion in the drawings.

Herein, the "schematic" means "serving as an example, instance, or description"; and any illustration, embodiment, described herein as "schematic" should not to be construed as a more preferred or more advantageous technical solution.

For the purpose of clarity, the portions of the drawings correlated to the present disclosure are merely shown in each drawing and are not intended to represent the actual structure of the product. In addition, to simplify the drawings and for the convenience of understanding, only one of the components having the same structure or function in some of the drawings is illustrated schematically or is labeled.

Fig. 1 is a schematic diagram illustrating a structure of a radiating element in a first embodiment of the present disclosure. Fig. 2 is a schematic diagram illustrating a structure of an oscillator balun circuit board in Fig. 1.

As shown in Figs. 1 and 2, the present disclosure provides a radiating element of an antenna, including: an oscillator radiation circuit board 1, on which oscillator radiation arms 11 arranged in pairs are printed; and a pair of oscillator balun circuit boards 2, which are used for supporting the oscillator radiation circuit board 1, and on which oscillator baluns are printed，wherein the pair of oscillator balun circuit boards 2 are mutually perpendicularly crossed to form oscillators vertical to each other in two directions of polarization; each of the oscillator baluns is provided with two slots 21 extending along the horizontal direction, and the two slots 21 are arranged at intervals in parallel along the height direction to form loading stubs 22 extending along the horizontal direction between the two slots 21; and the loading stubs 22 of the pair of oscillator balun circuit boards 2 are short-circuited so as to improve heteropolarization isolation.

A radiating body of the radiating element includes oscillator radiation arms 11 and oscillator baluns, wherein the oscillator radiation arms 11 are arranged in pairs and are printed on the oscillator radiation circuit board 1, and the oscillator baluns are printed on the oscillator balun circuit board 2. The oscillator balun circuit board 2 is vertically arranged below the oscillator radiation circuit board 1, thus supporting the oscillator radiation circuit board 1 to extend along the horizontal direction.

As shown in Fig. 1, the oscillator radiation arms 11 may be multiple, which are implemented by metal sheets, and the multiple oscillator radiation arms 11 are located in the same plane. The oscillator radiation arms 11 are arranged in pairs; and in this embodiment, the oscillator radiation arms 11 are arranged in two pairs, and the two pairs of oscillator radiation arms are perpendicular to each other. The so-called arranging in pairs may be such that each pair of oscillator radiation arms 11 is symmetrically distributed.

The oscillator balun circuit board 2 where oscillator baluns are located supports the oscillator radiation circuit board 1 where oscillator radiation arms 11 are located. Corresponding to the case that the oscillator radiation arms 11 are arranged in two pairs, as shown in Fig. 1, in this embodiment, two oscillator balun circuit boards 2 are provided and are perpendicularly crossed with each other to form a stable cross bracing structure; each oscillator balun circuit board 2 correspondingly supports a pair of oscillator radiation arms 11, and moreover, the extending direction of each oscillator balun circuit board 2 corresponds to the polarization direction of a pair of oscillator radiation arms 11. Therefore, the polarization directions of the two oscillator balun circuit boards 2 are perpendicular to each other.

Alternatively, shapes of the two oscillator balun circuit boards 2 are the same, but structures of the oscillator baluns printed thereon may be selected to be the same or different.

In the present embodiment, two slots 21 extending along the horizontal direction are formed on the oscillator baluns; and such a double-slot loading structure can form a loading stub 22 extending along the horizontal direction between the two slots 21; loading stubs 22 on the two oscillator baluns (two polarization directions) are connected in parallel. In this embodiment, two loading stubs 22 connected in parallel are short-circuited to form a high impedance equivalent to a quarter wavelength, thus suppressing the scattered field caused by size reduction and low profile mismatch, and achieving the purpose of improving the heteropolarization isolation of the antenna.

In the radiating element of this embodiment, slots 21 are combined with the short-circuited loading stubs 22 to solve the problems of poor bandwidth and performance caused by size reduction through parallel loading and polarization short circuit.

As shown in Fig. 3, a dotted line graph (written as 'Short polarization') represents the isolation of the radiating element when the loading stubs 22 are short-circuited, and a solid line graph(written as 'Open polarization') represents the isolation of the radiating element when the load stubs 22 are open-circuited. The isolation of the radiating element in this embodiment can be improved from 18 dB to 26 dB when the loading stubs 22 are short-circuited. In this embodiment, the heteropolarization isolation of the antenna is realized through the short-circuited loading stubs 22; and it is unnecessary to additionally arrange a separation barrier and reflective board between adjacent radiating elements, thus achieving the advantages of reducing process and material cost, lowering mould opening difficulty and improving consistency.

Figs. 4 to 6 are schematic diagrams illustrasting structures of a radiating element in a second embodiment of the present disclosure.

As shown in Fig. 6, each of the loading stubs 22 comprises a first loading stub 221 and a second loading stub 222; the first loading stub 221 and the second loading stub 222 respectively extend horizontally from both ends of the oscillator balun circuit board 2 towards a midline of the oscillator balun circuit board 2; and end portions of the first loading stub 221 and the second loading stub 222 are arranged at intervals. For example, the end portions of the first loading stub 221 and the second loading stub 222 face each other along the horizontal direction.

As shown in Fig. 4, end portions of the first loading stub 221 of the pair of oscillator balun circuit boards 2 are short-circuited. Further, as shown in Fig. 5, end portions of the second loading stub 222 of the pair of oscillator balun circuit boards 2 are open-circuited and connected in parallel.

End portions of the second loading stub 222 are suspended to form an open-circuited effect, and the open-circuited second loading stub 222 is used to realize an L-shaped loading equivalent LC (inductance capacitance) circuit, thus loading reactance through the LC circuit so as to achieve the effect of widening bandwidth.

In the present embodiment, two

loading stubs

221 and 222 are formed between two slots 21, and the two

loading stubs

221 and 222 have different connection modes, of which two first loading stubs 221 are short-circuited to form a high impedance equivalent to a quarter wavelength, thus suppressing the scattered field caused by size reduction and low profile mismatch, and achieving the purpose of improving the heteropolarization isolation of the antenna. The two second loading stubs 222 are open-circuited to load reactance through an equivalent LC circuit, thus further widening the bandwidth on the basis of isolation improvement.

In the radiating element of this embodiment, two

loading stubs

221 and 222 may be formed only by setting two slots 21 at intervals in parallel on the oscillator baluns on the basis reducing the size. Moreover, a combination of the different connection modes of the two

loading stubs

221 and 222 in parallel can achieve the purposes of improving the heteropolarization isolation and widening the bandwidth. The radiating element of this embodiment can achieve the same even more excellent bandwidth and performances on the basis of reducing the size of the radiation oscillator.

As shown in Fig. 7, a solid line graph(written as 'Return loss') represents the antenna return loss curve S11, and a dotted line graph(written as 'isolation') represents the insertion loss curve S21. A bandwidth of 700 Mhz can be achieved below 15 dB at present. In the second embodiment shown in Figs. 4 and 5, the length of the second loading stub 222, the size of the gap between the end portions of the two second loading stubs 222, and the width of the two slots 21 may be adjustable to adjust the reactance loaded by the LC circuit.

In a preferred embodiment, the second loading stub 222 has a length of 1/8 wavelength.

As shown in Fig. 8, each oscillator balun further includes: a feed circuit 23; and a parasitic feed circuit 24 adjacent to at least a portion of the feed circuit 23 for coupling with the feed circuit 23.

The feed circuit 23 is configured to supply power to each oscillator balun, and the feeding points thereof are mostly located at the bottom edge of the oscillator balun and extend upwards from the bottom edge of the oscillator balun. In this embodiment, a parasitic feed circuit 24 coupled to the feed circuit 23 is arranged nearby the feed circuit 23, and the homopolarization isolation is formed in a frequency band, through parasitic coupling to the feed circuit 23.

The technical solution of setting the parasitic feed circuit 24 in the embodiment may be combined with the technical solution of setting short-circuited loading stubs 22 of Fig. 1 connected in parallel in oscillator baluns of the first embodiment, thus simultaneously improving the homopolar and heteropolar isolation of the radiating element. Moreover, the technical solution of setting the parasitic feed circuit 24 in the embodiment may be also combined with the technical solution of setting short-circuited loading stubs 221 of Figs. 4 to 6 connected in parallel and open-circuited loading stubs 222 of Figs. 4 to 6 connected in parallel simultaneously in oscillator baluns of the second embodiment, thus further widening the bandwidth and improving the radiation performance of the radiation antenna on the basis of improving the homopolar and heteropolar isolation of the radiating element.

As shown in Fig. 8, to achieve superior antenna performance within a limited space, the parasitic feed circuit 24 includes a first parasitic stub 241 and a second parasitic stub 242 arranged in parallel with each other; the first parasitic stub 241 and the second parasitic stub 242 are arranged along the height direction of the oscillator balun circuit board 2, and the top ends thereof are connected in one piece.

That is, the parasitic feed circuit 24 is formed into an inverted U shape to increase the length of the parasitic feed circuit 24.

The reason for forming the inverted U shape is that the parasitic feed circuit 24 needs to be grounded. Therefore, bottom ends of the first parasitic stub 241 and the second parasitic stub 242 are disposed at the bottom edge of the oscillator balun circuit board 2; at least one of the first parasitic stub 241 and the second parasitic stub 242 is grounded through its bottom end. In an embodiment, bottom ends of the first parasitic stub 241 and the second parasitic stub 242 share a same bottom surface with the oscillator balun circuit board 2.

The technical solution, that is, "one or two end portions of the parasitic feed circuit 24 are grounded simultaneously" may be selected, so as to selectively adjust the homopolarization isolation within a frequency band in combination with the parasitic coupling to the feed circuit 23. In one embodiment, the radiating element in this embodiment can improve about 2 dB of homopolarization isolation and can further widen the bandwidth.

Usually, the feed circuit starts extending at the bottom edge of the oscillator balun and needs to be distributed over most of the areas on the oscillator balun circuit board 2, including both the width direction and the height direction at the same time, due to the feeding characteristic of components of the oscillator balun. Specifically, the feed circuit 23 includes a first feed stub 231 disposed along the height direction of the oscillator balun circuit board 2 and a second feed stub 232 bent inwards from the top of the first feed stub 231, i.e. the feed circuit 23 needs to extend from one end of the oscillator balun circuit board 2 toward another end of the oscillator balun circuit board 2 in the width direction, and thus requires the second feed stub 232 bent inwards.

In order to increase the space available to the configuration of the parasitic feed circuit 24 and increase the length of the parasitic feed circuit 24 as much as possible, the parasitic feed circuit 24 is disposed outside the first feed stub 231, so as to keep away from the second feed stub 232 bent inwards in the direction of extending upwards thereof.

A radiating antenna is provided in a further embodiment of the present disclosure, including a plurality of radiating elements described above, wherein the plurality of radiation elements are arranged on a substrate at intervals, and no boundary condition such as a dividing wall, a separation wall and a reflective board is arranged between adjacent radiating elements.

Based on the above technical solution, it can be seen that in this embodiment, two slots extending along the horizontal direction are formed on the oscillator baluns; and such a double-slot loading structure can form a loading stub extending along the horizontal direction between the two slots; loading stubs on the two oscillator baluns (two directions of polarization) are connected in parallel. In this embodiment, two loading stubs connected in parallel are short-circuited to form a high impedance equivalent to a quarter wavelength, thus suppressing the scattered field caused by low profile mismatch, and achieving the purposes of improving the heteropolarization isolation of the antenna.

In the embodiment, slots are combined with the short-circuited loading stubs by the radiating element to solve the problems of poor bandwidth and performance caused by size reduction through parallel loading and polarization short circuit. In the embodiment, the heteropolarization isolation of the antenna is realized through the short-circuited loading stubs; and it is unnecessary to additionally arrange a separation barrier and a reflective board between adjacent radiation elements, thus achieving the advantages of reducing process and material cost, lowering mould opening difficulty and improving consistency.

Further, the technical solution of setting the parasitic feed circuit in the embodiment may be combined with the technical solution of setting short-circuited loading stubs connected in parallel in oscillator baluns of the first embodiment, thus simultaneously improving the homopolar and heteropolar isolation of the radiating element. Moreover, the technical solution of setting the parasitic feed circuit in the embodiment may be also combined with the technical solution of setting short-circuited loading stubs connected in parallel and open-circuited loading stubs connected in parallel simultaneously in oscillator baluns of the second embodiment, thus further widening the bandwidth and improving the radiation performance of the radiation antenna on the basis of improving the homopolar and heteropolar isolation of the radiating element.

Herein, the wording "a/one" does not denote that the number of relevant portions in the present disclosure is limited to "only one", moreover, the wording "a/one" does not denote the exclusion of the case that the number of relevant portions in the present disclosure is "more than one".

Unless otherwise specified, the numerical ranges herein include not only the entire range within its two endpoints, but also include the several subranges subsumed therein.

The detailed description set forth above is intended to merely illustrate the possible embodiments of the present disclosure and is not intended to limit the protection scope of the present disclosure. Moreover, any other equivalent embodiment or alteration, such as a combination, partition or repetition of the features without departing from the spirit of the present disclosure shall fall within the protection scope of the present disclosure.

Claims

A radiating element of an antenna, characterized by, the radiating element comprises:

an oscillator radiation circuit board (1), on which oscillator radiation arms arranged in pairs are printed; and

a pair of oscillator balun circuit boards (2), configured to support the oscillator radiation circuit board (1) , on which oscillator baluns are printed, wherein the pair of oscillator balun circuit boards (2) are mutually perpendicularly crossed to form oscillators vertical to each other in two directions of polarization;

wherein each of the oscillator baluns is provided with two slots (21) extending along the horizontal direction, and the two slots (21) are arranged at intervals in parallel along the height direction to form loading stubs (22) extending along the horizontal direction between the two slots (21).
The radiating element according to claim 1, characterized by, each of the loading stubs (22) comprises a first loading stub (221),

wherein end portions of the first loading stub (221) of the pair of oscillator balun circuit boards (2) are short-circuited so as to form heteropolarization isolation.
The radiating element according to claim 2, characterized by, each of the loading stubs (22) further comprises: a second loading stub (222); the first loading stub (221) and the second loading stub (222) respectively extend horizontally from both ends of the oscillator balun circuit board (2) towards a midline of the oscillator balun circuit board (2); and end portions of the first loading stub (221) and the second loading stub (222) are arranged at intervals.
The radiating element according to claim 3, characterized by, end portions of the second loading stub (222) of the pair of oscillator balun circuit boards (2) are open-circuited and connected in parallel.
The radiating element according to claim 3, characterized by, the second loading stub (222) has a length of 1/8 wavelength.
The radiating element according to any one of claims 1 to 4, characterized by, each of the oscillator baluns further comprises:

a feed circuit (23); and

a parasitic feed circuit (24), adjacent to at least a portion of the feed circuit (23) for coupling with the feed circuit (23).
The radiating element according to claim 6, characterized by, the parasitic feed circuit (24) comprises a first parasitic stub (241) and a second parasitic stub (242) arranged in parallel; the first parasitic stub (241) and the second parasitic stub (242) are arranged along the height direction of the oscillator balun circuit board (2), and top ends thereof are connected in one piece.
The radiating element according to claim 7, characterized by, bottom ends of the first parasitic stub (241) and the second parasitic stub (242) share a same bottom surface with the oscillator balun circuit board (2); and

at least one of the first parasitic stub (241) and the second parasitic stub (242) is grounded by a bottom end thereof.
The radiating element according to claim 6, characterized by, the feed circuit (23) comprises a first feed stub (231) arranged along the height direction of the oscillator balun circuit board (2), and a second feed stub (232) bent inwards from a top end of the first feed stub (231); and

the parasitic feed circuit (24) is disposed outside the first feed stub (231).
A radiating antenna, characterized by, comprising a plurality of the radiating elements according to any one of claims 1 to 9, wherein the radiating elements are arranged on a substrate at intervals; and no dividing wall is arranged between adjacent radiating elements.