CN112186338A

CN112186338A - Broadband circularly polarized microstrip antenna

Info

Publication number: CN112186338A
Application number: CN202010999288.3A
Authority: CN
Inventors: 李俊; 詹敏峰; 唐开华
Original assignee: Guangzhou Jiesai Communication Planning And Design Institute Co ltd; GCI Science and Technology Co Ltd
Current assignee: Guangzhou Jiesai Communication Planning And Design Institute Co ltd; GCI Science and Technology Co Ltd
Priority date: 2020-09-22
Filing date: 2020-09-22
Publication date: 2021-01-05

Abstract

The invention discloses a broadband circularly polarized microstrip antenna, which comprises: the antenna comprises a dielectric substrate, an antenna port and two radiating unit groups, wherein the antenna port and the two radiating unit groups are arranged on the dielectric substrate; the two radiation unit groups comprise a first radiation unit group and a second radiation unit group, the first radiation unit group comprises at least two radiation units, and the second radiation unit group comprises at least two radiation units; the antenna port comprises an output end and two input ends, and the two input ends are respectively connected with the output end of the first radiating unit group and the output end of the second radiating unit group; the radiation units in each radiation unit group are connected through a feed circuit; the phases between two adjacent radiation elements in each radiation element group are different by 90 degrees. The embodiment of the invention provides a broadband circularly polarized microstrip antenna, which can effectively reduce the cost of the antenna while realizing the improvement of the bandwidth of the antenna.

Description

Broadband circularly polarized microstrip antenna

Technical Field

The invention relates to the technical field of antennas, in particular to a broadband circularly polarized microstrip antenna.

Background

With the development of mobile communication technology, circularly polarized antennas are also widely used, especially for receiving and transmitting RFID signals and satellite signals. The microstrip antenna has the unique advantages of small volume, light weight, thin section and the like, but the frequency band is narrow, the relative bandwidth of the common microstrip antenna is usually only 1% -6%, and the broadening of the frequency band is a key problem to be solved in the design of the circular polarized antenna. The existing microstrip antenna realizes bandwidth expansion by adding a parasitic element, improving the antenna profile, using a high dielectric constant dielectric plate and the like, but the existing microstrip antenna can improve the bandwidth, but has a complex structure and higher cost.

Disclosure of Invention

The invention provides a broadband circularly polarized microstrip antenna, which aims to solve the technical problems of complicated structure and high cost of the microstrip antenna in the prior art.

A first embodiment of the present invention provides a broadband circularly polarized microstrip antenna, including:

the antenna comprises a dielectric substrate, an antenna port and two radiating unit groups, wherein the antenna port and the two radiating unit groups are arranged on the dielectric substrate;

the two radiating element groups include a first radiating element group and a second radiating element group, the first radiating element group includes at least two radiating elements, and the second radiating element group includes at least two radiating elements;

the antenna port comprises an output end and two input ends, and the two input ends are respectively connected with the output end of the first radiating element group and the output end of the second radiating element group;

the radiation units in each radiation unit group are connected through a feed circuit; the phases of two adjacent radiation units in each radiation unit group are different by 90 degrees.

Furthermore, the microstrip antenna further includes a plurality of one-to-two power dividers, and the radiation unit in each radiation unit group is connected to the antenna port through one corresponding one-to-two power divider.

Further, feeding phases of the first and second radiating element groups are different by 180 degrees.

Further, the radiation unit is a rectangular microstrip antenna.

Further, the one-to-two power divider is provided with a balance resistor for balancing the current of the one-to-two power divider.

The embodiment of the invention provides a broadband circularly polarized microstrip antenna, wherein two radiation unit groups are arranged on a dielectric substrate, each radiation unit group at least comprises two radiation units, the phase difference between every two adjacent radiation units in each radiation unit group is 90 degrees, and the radiation units are mutually offset and inhibited during synthesis, so that the impedance bandwidth and the axial ratio bandwidth can be effectively improved.

Drawings

Fig. 1 is a schematic structural diagram of a broadband circularly polarized microstrip antenna according to an embodiment of the present invention;

fig. 2 is another schematic structural diagram of a broadband circularly polarized microstrip antenna according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a balanced resistance structure of a broadband circularly polarized microstrip antenna according to an embodiment of the present invention;

fig. 4 is a graph of return loss versus frequency of a broadband circularly polarized microstrip antenna according to an embodiment of the present invention;

fig. 5 is a graph of axial ratio versus frequency of a broadband circularly polarized microstrip antenna according to an embodiment of the present invention.

Wherein the drawings in the attached drawings of the specification are marked as follows:

1. a dielectric substrate; 2. a radiation unit; 21. a first radiation unit; 22. a second radiation unit; 23. a third radiation unit; 24. a fourth radiation unit; 3. a feed circuit; 4. a one-to-two power divider; 5 an antenna port; 6. balancing the resistance.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it is to be understood that the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

Referring to fig. 1-2, a first embodiment of the present invention provides a wideband circularly polarized microstrip antenna as shown in fig. 1-2, including:

the antenna comprises a dielectric substrate 1, an antenna port 5 and two radiating unit groups, wherein the antenna port 5 and the two radiating unit groups are arranged on the dielectric substrate 1;

the two radiation element groups include a first radiation element group and a second radiation element group, the first radiation element group includes at least two radiation elements 2, and the second radiation element 2 includes at least two radiation elements 2; the antenna port 5 comprises an output end and two input ends, and the two input ends are respectively connected with the output end of the first radiating unit group and the output end of the second radiating unit group;

the radiation elements 2 in each radiation element group are connected through a feed circuit 3; the phases between two adjacent radiation elements 2 in each radiation element group are different by 90 degrees. In the embodiment of the present invention, the feeding directions of each radiation unit 2 are different, that is, the amplitude and the phase of the radiation direction of each radiation unit 2 are different, the phase difference between two adjacent radiation units 2 in each radiation unit group is 90 degrees, and the radiation units 2 are mutually offset and suppressed during synthesis, so that the impedance bandwidth and the axial ratio bandwidth can be effectively improved.

In the embodiment of the present invention, each of the first radiation unit group and the second radiation unit group is provided with 2 radiation units 2, and each radiation unit 2 is connected to an antenna port 5 through a one-to-two power divider 4 and a feeding circuit 3. Optionally, the dielectric substrate 1 is a PCB substrate, and the material thereof is FR4FR4 epoxy double-sided board.

As a specific implementation manner of the embodiment of the present invention, the microstrip antenna further includes a plurality of one-to-two power dividers 4, and the radiation unit 2 in each radiation unit group is connected to the antenna port 5 through one corresponding one-to-two power divider 4.

As a specific implementation of the embodiment of the present invention, the feeding phases of the first radiating element group and the second radiating element group are different by 180 degrees.

In the embodiment of the present invention, the phases of the first radiation unit group and the second radiation unit group are different by 180 degrees, and the first radiation unit 2 and the second radiation unit 2 cancel and suppress each other when combined, so that the bandwidth of the antenna can be effectively improved.

As a specific implementation manner of the embodiment of the present invention, the radiation unit 2 is a rectangular microstrip antenna.

In the embodiment of the invention, the feeding mode of the rectangular microstrip antenna is side feeding. Optionally, the shape of the radiation unit 2 includes, but is not limited toIn the form of polygon, rectangle, circle and ellipse, the shape of the radiation unit 2 in this embodiment is square, and the side length thereof is 0.4-0.5 λ_g，λ_gIs a microstrip line wavelength, so that the radiation unit 2 can form a circularly polarized wave; and a two-point feeding structure is formed according to the one-to-two power divider 4, and the one-to-two power divider 4 forms two paths of signals with equal amplitude and 90-degree phase difference to feed the radiation unit 2. Referring to fig. 2, after the second radiation unit 22 rotates 90 degrees counterclockwise relative to the first radiation unit 21, the second radiation unit 22 is connected together through the one-to-two power divider 4, the third radiation unit 23 rotates 180 degrees relative to the second radiation unit 22, the fourth radiation unit 24 rotates 180 degrees relative to the first radiation unit 21, and the third radiation unit 23 is connected to the fourth radiation unit 22 through the one-to-two power divider 4 and is connected to the antenna main port through the other one-to-two power divider 4.

Referring to fig. 3, the one-to-two power divider 4 is provided with a balancing resistor 6 for balancing the current of the one-to-two power divider 4.

In the embodiment of the invention, the balance resistor 6 is used for balancing the power dividing current, so that the amplitude and the phase of the power dividing circuit can be uniformly distributed, and the bandwidth of the antenna can be improved. Optionally, the balancing resistor 6 is a 100 ohm balancing resistor 6.

Please refer to fig. 4, which is a graph illustrating a relationship between return loss and frequency of a wideband circularly polarized microstrip antenna according to an embodiment of the present invention; please refer to fig. 5, which is a diagram illustrating the relationship between the axial ratio and the frequency of a wideband circularly polarized microstrip antenna according to an embodiment of the present invention. As can be seen from fig. 4-5, the broadband circularly polarized microstrip antenna according to the embodiment of the present invention has good return loss and axial ratio in the frequency band range of 790-960 MHz, and the relative bandwidth reaches 20%.

The embodiment of the invention has the following beneficial effects:

in the embodiment of the present invention, two radiation unit groups are disposed on a dielectric substrate 1, each radiation unit group at least includes two radiation units 2, a phase difference between two adjacent radiation units 2 in each radiation unit group is 90 degrees, and when the radiation units 2 are synthesized, impedance bandwidth and axial ratio bandwidth can be effectively improved by canceling and suppressing each other.

Furthermore, the phases of the first radiating element group and the second radiating element group of the embodiment of the present invention are different by 180 degrees, and the first radiating element 2 and the second radiating element 2 cancel and suppress each other when they are combined, so that the bandwidth of the antenna can be effectively improved

The foregoing is a preferred embodiment of the present invention, and it should be noted that it would be apparent to those skilled in the art that various modifications and enhancements can be made without departing from the principles of the invention, and such modifications and enhancements are also considered to be within the scope of the invention.

Claims

1. A wideband circularly polarized microstrip antenna comprising:

2. The broadband circularly polarized microstrip antenna according to claim 1 wherein each of the radiating element groups further comprises a plurality of one-to-two power dividers, and the radiating elements in each of the radiating element groups are connected to the antenna port through a corresponding one-to-two power divider.

3. The broadband circularly polarized microstrip antenna of claim 1 wherein the feed phases of the first and second radiating element groups are 180 degrees out of phase.

4. The wideband circularly polarized microstrip antenna of claim 1 wherein the radiating element is a rectangular microstrip antenna.

5. The broadband circularly polarized microstrip antenna according to claim 2 wherein the one-to-two power divider is provided with a balancing resistor for balancing the current of the one-to-two power divider.