CN114421149A

CN114421149A - Compact broadband crescent patch pair antenna

Info

Publication number: CN114421149A
Application number: CN202210085812.5A
Authority: CN
Inventors: 胡南; 谢文青; 刘建睿; 刘爽; 赵丽新
Original assignee: Beijing Xingyinglian Microwave Technology Co ltd
Current assignee: Beijing Xingyinglian Microwave Technology Co ltd
Priority date: 2022-01-25
Filing date: 2022-01-25
Publication date: 2022-04-29
Also published as: CN116053793A; CN116053793B

Abstract

The invention discloses a compact broadband crescent patch pair antenna, which comprises a dielectric substrate, wherein two symmetrical radiation patches are formed on one surface of the dielectric substrate, the two radiation patches feed in opposite directions with equal amplitude to cause that the current directions on the two patches are the same, and then broadside radiation is carried out; one end of each radiating patch close to the inner side is provided with a connecting part penetrating through the dielectric substrate, the other surface of the dielectric substrate is provided with a feeding ground plane, and the radiating patches and the feeding ground planes corresponding to the radiating patches are connected together through the connecting parts; and a reflector ground plane is formed on one side opposite to the feed ground plane, and one ends of the two coaxial cables penetrate through the reactor ground plane and are respectively connected with the feed ground plane. The bandwidth of the antenna can reach an octave, and the antenna has good radiation characteristics in the full frequency band.

Description

Compact broadband crescent patch pair antenna

Technical Field

The invention relates to the technical field of antennas, in particular to a compact broadband crescent patch pair antenna.

Background

Due to the proliferation of modern broadband communication systems, the need for small, low cost printed broadband antennas is increasing. Coplanar waveguide (CPW) fed printed wide slot antennas and CPW fed monopole antennas have wide bandwidths and omnidirectional radiation patterns. However, in certain applications, directional radiation is required. A tapered slot line antenna (TSA) is an end-fire broadband antenna that can provide bandwidths greater than 3: 1. Aperture Stacked Patch (ASP) antennas can increase the bandwidth of microstrip antennas to over 90%. However, these types of antennas are always of relatively large height. In addition, the VSWR bandwidth of the series-fed printed strip dipole exceeds 30%, the antenna height is low, but the frequency band is not wide enough.

Disclosure of Invention

The invention aims to solve the technical problem of how to provide a compact broadband crescent patch pair antenna which has the advantages that the bandwidth of the antenna can reach an octave and has good radiation characteristics in a full frequency band.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a compact broadband crescent patch pair antenna, characterized in that: the broadband wide-side radiation antenna comprises a dielectric substrate, wherein two radiation patches which are symmetrical to each other are formed on one surface of the dielectric substrate, the two radiation patches feed in opposite directions with equal amplitude, so that the current directions on the two patches are the same, and then wide-side radiation is performed; one end of each radiating patch close to the inner side is provided with a connecting part penetrating through the dielectric substrate, the other surface of the dielectric substrate is provided with a feeding ground plane, and the radiating patches and the feeding ground planes corresponding to the radiating patches are connected together through the connecting parts; and a reflector ground plane is formed on one side opposite to the feed ground plane, one ends of two coaxial cables penetrate through the reactor ground plane and are respectively connected with the feed ground plane, and the other ends of the coaxial cables are connected with a coaxial interface.

The further technical scheme is as follows: the radiation patch is crescent-shaped and comprises a crescent part and rectangular parts, the opening of the crescent part is arranged outwards, the rectangular parts are connected with the inner side ends of the crescent part, the two rectangular parts are arranged oppositely, and a certain distance is kept between the inner side ends of the two rectangular parts.

The further technical scheme is as follows: the distance between two end points of the outer arc of the crescent part is 2L, and L =11 mm; the distance from the midpoint of a line between the two end points of the outer arc of the crescent to the midpoint of the inner arc of the crescent is L R1=11 x 1.75=19.25 mm; the distance from the midpoint of the line between the two end points of the outer arc of the crescent to the midpoint of the outer arc of the crescent is L R2=11 0.2=22 mm.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in: the patch-to-antenna described herein utilizes coupling between the two patches, and measurements and simulations show that the antenna provides about 87% of the bandwidth and has good radiation performance over the full frequency band.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Fig. 1a is a schematic cross-sectional structure diagram of an antenna according to an embodiment of the present invention;

fig. 1b is a schematic top view of a pair of radiating patches in the antenna according to the embodiment of the present invention;

fig. 2 is a graph of S-parameters of an antenna according to an embodiment of the present invention;

figure 3a is the radiation pattern of the antenna (2.5 GHz);

figure 3b is the radiation pattern of the antenna (4.4 GHz);

figure 3c is the radiation pattern of the antenna (6 GHz);

figure 3d is the radiation pattern of the antenna (6.5 GHz);

FIG. 4a is the antenna characteristic (4.3 GHz) with/without reflective floor;

FIG. 4b is the antenna characteristics (active reflection coefficient) of the reflective/non-reflective floor;

FIG. 5 is the gain in the direction perpendicular to the patch;

FIG. 6a is the active reflection coefficient (change L) of the antenna;

FIG. 6b is the active reflection coefficient of the antenna (change fd);

FIG. 6c is the active reflection coefficient of the antenna (change R1);

FIG. 6d is the active reflection coefficient of the antenna (change h);

wherein: 1. a dielectric substrate; 2. a radiation patch; 3. a connecting portion; 4. a feed ground plane; 5. a reactor ground plane; 6. a coaxial cable; 2-1, crescent; 2-2, rectangular part.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, 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 invention.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

As shown in fig. 1a, the embodiment of the present invention discloses a compact broadband crescent patch pair antenna, which includes a dielectric substrate 1, wherein two radiation patches 2 symmetrical to each other are formed on one surface of the dielectric substrate 1, and the two radiation patches 2 feed in opposite phases with equal amplitude, so that the directions of currents on the two radiation patches are the same, and then broadside radiation is performed; one end of each radiation patch 2 close to the inner side is provided with a connecting part 3 penetrating through the dielectric substrate 1, the other surface of the dielectric substrate 1 is provided with a feeding ground plane 4, and the radiation patches 2 and the feeding ground planes 4 corresponding to the radiation patches are connected together through the connecting parts 3; a reflector ground plane 5 is formed on one side opposite to the feed ground plane 4, one ends of two coaxial cables 6 penetrate through the reactor ground plane 5 and then are respectively connected with the feed ground plane 4, and the other ends of the coaxial cables 6 are connected with a coaxial interface.

As shown in fig. 1b, the radiation patch 2 is crescent-shaped, the radiation patch comprises a crescent part 2-1 and a rectangular part 2-2, the opening of the crescent part 2-1 is arranged outwards, the rectangular part 2-2 is connected with the middle part of the inner arc of the crescent part 2-1, the two rectangular parts 2-2 are oppositely arranged, and a certain distance is kept between the inner end parts of the two rectangular parts 2-2.

The antenna comprises two metal crescent-shaped radiating patches on the top of the substrate and two small feed ground planes on the bottom. The two patches are fed back in 180 degrees phase, resulting in lateral radiation from the antenna. The reflector ground plane is mounted behind the radiating patch to increase radiation in the desired direction, similar to a dipole reflector antenna.

The crescent-shaped radiation patch is obtained by subtracting two concentric ellipses. Two small feed ground planes are on the other side of the substrate, the radiating patches feed in opposite phases with equal amplitude, resulting in the same current direction on the two patches, and broadside radiation is performed. If both patches are fed with the same phase and oriented in the same direction, the impedance bandwidth will become narrower. Furthermore, the fact that the maximum radiation direction is not perpendicular to the microstrip patch is due to the asymmetry of the antenna structure. The coupling between the two patches is utilized in the design of the antenna in order to make the active reflection coefficient of the antenna better, wherein the reflector ground plane is used to change the omnidirectional radiation into directional radiation.

Further, as shown in fig. 1a-1b, the distance between the two end points of the outer arc of the crescent 2-1 is 2L, and L =11 mm; the distance from the midpoint of the connecting line between the two end points of the outer arc of the crescent 2-1 to the midpoint of the inner arc of the crescent 2-1 is L R1=11 x 1.75=19.25 mm; the distance from the midpoint of the line between the two end points of the outer arc of the crescent 2-1 to the midpoint of the outer arc of the crescent 2-1 is L R2=11 0.2=22 mm. Preferably, the diameter of the feed ground plane 4 is larger than the diameter of the connection portion 3 and larger than the diameter of the coaxial cable 6. The distance between two of said feed ground planes 4 is fd, fd =4 mm; the diameter of the feed ground plane 4 is pl, pl =6 mm; the reflector ground plane 4 has a dimension of 100 x 84 mm, and the distance between the dielectric substrate 1 and the reactor ground plane 4 is h, h =20 mm.

To analyze the impedance and pattern, the proposed antenna was first simulated by HFSS and then fabricated on a substrate with a dielectric constant of 2.2 and a thickness of 0.787 mm. The 3dB power divider is connected to the antenna feed port in a 180 DEG reversed manner. The reflector ground plane size is 100 x 84 mm. The antenna optimization parameters are as follows according to the configuration in fig. 1a-1 b: l =11mm, R1=1.75mm, R2=0.2mm, f =4mm, fd =4mm, pl =6mm, h =20 mm. Fig. 2 shows the reflection coefficient and the coupling coefficient between two patches. It can be seen that 2.6-2.8GHz is greater than 9.6dB (vswr), 2.6-4GHz is also greater than 9.6dB, but in the 2.6-6.6GHz band, the active reflection coefficient is less than 9.6dB due to the coupling with the two patches. Since both ports are excited during operation of the antenna, the active reflection coefficient is more valuable in practical applications. The reflection coefficient measured at the input port of the power divider is almost below 9.6dB in the range of 2.6-6.6GHz, which is consistent with the simulated active reflection coefficient. Since the stability of the power dividers is not very good, their measured reflection coefficients fluctuate. In addition, the shape of the patch was found by simulation to be not a critical point for the antenna. Due to the larger area, the elliptical band is wider than the triangular band. The crescent shape allows the antenna to be miniaturized a little, but not much. Patches of different shapes can be designed as desired.

Active reflection coefficients of the antennas in fig. 6a-6d fig. 6a changes L, fig. 6b changes fd, fig. 6c changes R1, fig. 6d changes h; the radiation patterns of the antenna at the frequencies of 2.5GHz, 4.4GHz, 6GHz and 6.5GHz are shown in fig. 3 a-3 d. Although active reflection coefficients above 6GHz are acceptable, good uniformity of the radiation pattern is impaired. Such an antenna can be seen as an inverted binary array, arranged on the broad side of the reflecting surface. As the frequency increases, the distance between the radiating surface and the reflecting surface approaches 0.5 wavelength, which causes the depth in the broadside direction to warp downward. In conclusion, the antenna can well cover 2.6-6 GHz. Additionally, the front-to-back ratio is greater than 15 dB. It can be seen from fig. 4a that the front-to-back ratio is improved, about 20 dB, using the reflector ground plane at 4.3 GHz. Of course, the introduction of the reflector ground plane affects the reflection coefficient of the antenna. As shown in fig. 4 b), the available impedance band of the reflector-less antenna is shifted to higher frequencies. The gain at the broadside, perpendicular to the direction of the patch, is shown in fig. 5. It can be seen that the measured gain is less than the simulated gain, which may be due to attenuation by the power divider. The effect of changing the parameters is that all but one of the parameter dimensions remain unchanged at the values described above. Fig. 6a depicts the effect of varying the length of the semi-major axis of the ellipse (L) on the active reflection coefficient. It can be seen that the first resonant frequency of the antenna decreases as L increases and the frequency band becomes wider, but the reflection coefficient at some frequency points of the frequency band is greater than 9.6 dB. The effect of varying the distance between the two patches (fd) is shown in fig. 6 b. This is a key parameter as it contributes to the whole frequency band. Fig. 6c shows the effect of changing the ellipse ratio (R1). It is observed that this may slightly adjust the properties in fig. 6d, the thickness h of the antenna is varied. It should be noted that it serves to control the matching characteristics of the antenna over the entire frequency band. The resonant frequency can be adjusted to design a practical antenna.

The antenna consists of two simple patch pairs with opposite phase feeds. An antenna with a size of about 54.5 mm was constructed and tested, taking into account the coupling between the two patches in the design. Simulation results show that the active reflection coefficient of the antenna in a frequency band of 2.6-6GHz is less than 9.6 dB. The coupling between the two patches is applied during the design process. The bandwidth of the antenna reaches octave. The antenna has good radiation characteristics in the full frequency band.

Claims

1. A compact broadband crescent patch pair antenna, characterized in that: the broadband wide-angle broadband antenna comprises a dielectric substrate (1), wherein two symmetrical radiation patches (2) are formed on one surface of the dielectric substrate (1), the two radiation patches (2) feed in opposite directions with equal amplitude, so that the current directions on the two radiation patches are the same, and then broadside radiation is performed; one end of each radiating patch (2) close to the inner side is provided with a connecting part (3) penetrating through the dielectric substrate (1), the other surface of the dielectric substrate (1) is provided with a feeding ground plane (4), and the radiating patches (2) and the feeding ground planes (4) corresponding to the radiating patches are connected together through the connecting parts (3); and a reflector ground plane (5) is formed on one side opposite to the feed ground plane (4), one ends of two coaxial cables (6) penetrate through the reactor ground plane (5) and then are respectively connected with the feed ground plane (4), and the other ends of the coaxial cables (6) are connected with a coaxial interface.

2. The compact broadband crescent patch pair antenna of claim 1, wherein: the radiation patch (2) is crescent-shaped and comprises a crescent part (2-1) and a rectangular part (2-2), an opening of the crescent part (2-1) is arranged outwards, the rectangular part (2-2) is connected with the middle of an inner arc of the crescent part (2-1), the rectangular parts (2-2) are arranged oppositely, and a certain distance is kept between the inner end parts of the rectangular parts (2-2).

3. The compact broadband crescent patch pair antenna of claim 2, wherein: the distance between two end points of the outer arc of the crescent (2-1) is 2L, and L =11 mm; the distance from the midpoint of the line between the two end points of the outer arc of the crescent (2-1) to the midpoint of the inner arc of the crescent (2-1) is L R1=11 x 1.75=19.25 mm; the distance from the midpoint of the line between the two end points of the outer arc of the crescent (2-1) to the midpoint of the outer arc of the crescent (2-1) is L R2=11 0.2=22 mm.

4. The compact broadband crescent patch pair antenna of claim 2, wherein: the rectangular portion (2-2) has a length f, f =4 mm.

5. The compact broadband crescent patch pair antenna of claim 1, wherein: the width of the rectangular part (2-2) is smaller than the width of the crescent part (2-1).

6. The compact broadband crescent patch pair antenna of claim 1, wherein: the diameter of the feed ground plane (4) is greater than the diameter of the connection portion (3) and greater than the diameter of the coaxial cable (6).

7. The compact broadband crescent patch pair antenna of claim 1, wherein: -the distance between two of said feed ground planes (4) is fd, fd =4 mm; the diameter of the feed ground plane (4) is pl, pl =6 mm.

8. The compact broadband crescent patch pair antenna of claim 1, wherein: the reflector ground plane (4) has a dimension of 100 x 84 mm, and the distance between the dielectric substrate (1) and the reactor ground plane (4) is h, h =20 mm.

9. The compact broadband crescent patch pair antenna of claim 1, wherein: the dielectric substrate (1) has a dielectric constant of 2.2 and a thickness dh, dh =0.787 mm.

10. The compact broadband crescent patch pair antenna of claim 1, wherein: the length and width of the feed ground plane (4) are greater than the length and width of the dielectric substrate (1), respectively.