CN206271883U - A circularly polarized patch antenna for medical detection - Google Patents

Abstract

The embodiment of the utility model discloses a circularly polarized patch antenna for medical detection, which is used to solve the problem that the existing circularly polarized patch antenna has a complex structure, difficult integration, high cost, large volume and lack of Directional technical issues. A circularly polarized patch antenna for medical detection according to an embodiment of the utility model includes: an elliptical patch, a microstrip feeder, a single-layer double-sided PCB board, and a grooved floor; wherein the microstrip feeder is protrudingly connected to the The outer periphery of the elliptical patch; the grooved floor includes a hollowed out elliptical groove and a rectangular patch; the rectangular patch is recessed in the elliptical groove; the annular seam formed by the elliptical groove and the elliptical patch Capacitive loading is formed; the elliptical patch and the rectangular patch are coupled and short-circuited to form inductive loading.

Description

A circularly polarized patch antenna for medical detection

technical field

The utility model relates to the field of antennas and microwaves, in particular to a circularly polarized patch antenna for medical detection.

Background technique

With the development of modern communication technology, pure linear polarization is difficult to meet the communication requirements. Circularly polarized antennas can receive incoming waves of any polarization mode, and their radiated waves can also be received by antennas of any polarization mode. They have the advantages of rotation orthogonality, ability to suppress cloud and rain interference, and anti-multipath reflection.

Microstrip circularly polarized antennas are widely used in wireless applications due to the combination of the advantages and characteristics of both microstrip antennas and circularly polarized antennas, such as: measurement, communication, satellite, aerospace, global positioning system and RFID systems and other satellites The development of communication, remote control and telemetry technology.

At present, the microstrip circularly polarized antennas that can be formed in communication and measurement and control systems mainly have the following structural forms. Although they have their own characteristics in performance, they all have certain shortcomings.

1. Coaxial feed circularly polarized microstrip antenna. This type of antenna has the characteristics of wide impedance and axial ratio bandwidth, but it is difficult to integrate the circuit board, which is not conducive to installation.

2. Corner-cutting circularly polarized microstrip antenna, this type of antenna has a simple structure and low profile, but the axial ratio and standing wave bandwidth of the antenna are less than 2%.

3. The circularly polarized microstrip antenna form with an external circularly polarized bridge. The axial ratio and standing wave bandwidth of the microstrip antenna in this form are relatively wide. Usually, the axial ratio bandwidth of less than 3dB is greater than 15%, and the standing wave bandwidth of less than 2dB is greater than 20%, but the external circular polarization bridge takes up a lot of space, the feeder is long, and the difference loss is large, which is not conducive to the integration of antenna and network.

4. It is a current research hotspot to use single-side feed technology to realize circular polarization, but the structure is complex and difficult to realize. Therefore, simplifying its structural design becomes the key to the design.

5. Medical testing equipment requires antennas to be small in size and have directional performance, but most circularly polarized antennas do not have directional properties, which is an urgent problem to be solved in the field of medical testing.

Utility model content

The embodiment of the utility model discloses a circularly polarized patch antenna for medical detection, which solves the problem that the existing circularly polarized patch antenna has a complex structure, difficult integration, high cost, large volume and lack of orientation sexual technical issues.

The embodiment of the utility model provides a circularly polarized patch antenna for medical detection, including:

Elliptical patch, microstrip feeder, single-layer double-sided PCB board, grooved floor;

The microstrip feeder is protrudingly connected to the outer periphery of the elliptical patch;

The grooved floor includes hollowed out oval grooves and rectangular patches;

The rectangular patch is recessed in the elliptical groove;

The annular seam formed by the elliptical groove and the elliptical patch constitutes capacitive loading;

The elliptical patch and the rectangular patch are coupled and short-circuited to form inductive loading.

Preferably,

The working frequency of the circularly polarized patch antenna is 5.8GHz ISM frequency band.

Preferably,

The long axis a1 of the elliptical patch is 0.3-0.4 times the wavelength corresponding to the operating frequency of the circularly polarized patch antenna, the long axis a1 of the elliptical patch and the short axis b1 of the elliptical patch The ratio is 1.04-1.05.

Preferably,

The single-layer double-sided PCB board is FR4_epoxy microwave material, the relative dielectric constant is 4-5, the tangent loss is 0-0.05, the thickness is 0-2mm, the thickness of the double-sided copper clad board is 30-40 μm, and the length L1 is 30-35mm, width W1 is 30-50mm.

Preferably,

The input impedance of the microstrip feeder is 50Ω, the length L2 is 8mm, and the width W2 is 1.82mm.

Preferably,

The area of the elliptical groove is larger than the area of the elliptical patch.

Preferably,

The major axis a2 of the elliptical groove is 15-30 mm, and the minor axis b2 is 21-22 mm.

Preferably,

The length L3 of the rectangular patch is 10-20 mm, and the width W3 is 1.6-2.0 mm.

Preferably,

The projection angle between the major axis of the elliptical slot and the microstrip feeder is 40-50 degrees;

Preferably,

The angle between the long axis of the elliptical patch and the microstrip feeder line is 40-50 degrees.

As can be seen from the above technical solutions, the utility model embodiment has the following advantages:

The embodiment of the utility model provides a circularly polarized patch antenna for medical detection, including: an elliptical patch, a microstrip feeder, a single-layer double-sided PCB board, and a grooved floor; wherein the microstrip feeder is protrudingly connected At the outer periphery of the elliptical patch; the grooved floor includes a hollowed out elliptical groove and a rectangular patch; the rectangular patch is recessed in the elliptical groove; the elliptical groove and the elliptical patch are formed The circular seam constitutes capacitive loading; the coupled short circuit of the elliptical patch and the rectangular patch constitutes inductive loading. In this embodiment, the circular polarization, simplification, miniaturization and directional design of the antenna are realized by loading capacitance and inductance, and the advantages and characteristics of the combination of the microstrip antenna and the circular polarization antenna are fully utilized, and the performance of the antenna is relatively high. High, solid, high practicability, and low cost, the antenna is designed with single-point feed, simple in structure, easy to integrate, compared with other circularly polarized microstrip antennas, no external circularly polarized feed network is required, and a relatively Good circularly polarized radiation effect. In addition, the design realizes the integrated design of antenna and network, and can realize the design of array antenna. It is suitable for medical detection equipment requiring circularly polarized antennas, and solves the problem of existing circularly polarized patches. The antenna structure is relatively complex, the integration is difficult, the cost is high, the volume is large, and there are technical problems of non-directionality.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are only some embodiments of the present utility model, and those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

Fig. 1 is a schematic structural diagram of an embodiment of a circularly polarized patch antenna device for medical detection provided in an embodiment of the utility model;

Fig. 2 is a structural diagram of an elliptical patch of a circularly polarized patch antenna device for medical detection provided in an embodiment of the utility model;

Fig. 3 is a structural diagram of a grooved floor of a circularly polarized patch antenna device for medical detection provided in an embodiment of the utility model;

Fig. 4 is a return loss diagram of a circularly polarized patch antenna device for medical detection provided in an embodiment of the utility model;

Fig. 5 is a gain pattern on the xz and yz sections of a circularly polarized patch antenna device for medical detection provided in the embodiment of the utility model;

Fig. 6 is a three-dimensional gain pattern diagram of a circularly polarized patch antenna device for medical detection provided in an embodiment of the utility model.

detailed description

The embodiment of the utility model discloses a circularly polarized patch antenna for medical detection, which is used to solve the problem that the existing circularly polarized patch antenna has a complex structure, difficult integration, high cost, large volume and lack of Directional technical issues.

Please refer to Fig. 1, a circularly polarized patch antenna for medical detection provided in the embodiment of the utility model, including:

Elliptical patch 1, microstrip feeder 2, single-layer double-sided PCB board, grooved floor 4;

The microstrip feeder 2 is protrudingly connected to the outer periphery of the elliptical patch 1;

The grooved floor 4 includes a hollowed-out oval groove 5 and a rectangular patch 6;

The rectangular patch 6 is recessed in the oval groove 5;

The annular seam formed by the elliptical groove 5 and the elliptical patch 1 constitutes capacitive loading;

The elliptical patch 1 and the rectangular patch 6 are coupled and short-circuited to form inductive loading.

further,

The working frequency of the circularly polarized patch antenna is 5.8GHz ISM frequency band.

further,

The major axis a1 of the elliptical patch 1 is 0.3-0.4 times the wavelength corresponding to the operating frequency of the circularly polarized patch antenna, the major axis a1 of the elliptical patch 1 and the short axis of the elliptical patch 1 The shaft b1 shaft ratio is 1.04-1.05.

further,

The single-layer double-sided PCB board is FR4_epoxy microwave material, the relative dielectric constant is 4-5, the tangent loss is 0-0.05, the thickness is 0-2mm, the thickness of the double-sided copper clad board is 30-40 μm, and the length L1 is 30-35mm, width W1 is 30-50mm.

further,

The input impedance of the microstrip feeder 2 is 50Ω, the length L2 is 8mm, and the width W2 is 1.82mm.

further,

The area of the elliptical groove 5 is larger than the area of the elliptical patch.

further,

The major axis a2 of the oval groove 5 is 15-30 mm, and the minor axis b2 is 21-22 mm.

further,

The length L3 of the rectangular patch 6 is 10-20mm, and the width W3 is 1.6-2.0mm.

further,

The projection angle between the major axis of the elliptical groove 5 and the microstrip feeder 2 is 40-50 degrees;

further,

The included angle between the long axis of the elliptical patch 1 and the microstrip feeder 2 is 40-50 degrees.

Please refer to Fig. 1, a circularly polarized patch antenna for medical detection provided in the embodiment of the utility model, including:

Elliptical patch 1, microstrip feeder 2, rectangular single-layer double-sided PCB board 3, grooved floor 4;

The microstrip feeder 2 protrudes outside the ellipse patch 1, and the microstrip feeder 2 is connected to the ellipse circumference of the ellipse patch 1;

The grooved floor 4 includes a hollowed-out oval groove 5 and a rectangular patch 6;

The rectangular patch 6 is recessed in the oval groove 5;

The annular seam formed by the elliptical groove 5 and the elliptical patch 1 constitutes capacitive loading;

The elliptical patch 1 and the rectangular patch 6 are coupled and short-circuited to form inductive loading;

The grooved floor 4 is rectangular;

The length and width of the grooved floor 4 are respectively the same as the length and width of the rectangular single-layer double-sided PCB board 3 .

further,

The working frequency of the circularly polarized patch antenna is 5.8GHz ISM frequency band.

further,

As shown in Figure 2, the major axis a1 of the elliptical patch 1 antenna is 0.34 times the wavelength corresponding to the operating frequency of the circularly polarized patch antenna, and the major axis a1 of the elliptical patch 1 antenna and the elliptical patch antenna The minor axis b1 axial ratio of the chip 1 antenna is 1.0438.

further,

As shown in Figure 2, the rectangular single-layer double-sided PCB board 3 is made of FR4_epoxy microwave material, the relative dielectric constant is 4.4, the tangent loss is 0.02, the thickness is 1mm, the thickness of the double-sided copper clad board is 35μm, and the length L1 is 33.5mm , the width W1 is 40mm.

further,

As shown in FIG. 2 , the input impedance of the microstrip feeder 2 is 50Ω, the length L2 is 8mm, and the width W2 is 1.82mm.

further,

The area of the elliptical groove 5 is larger than the area of the elliptical patch 1 .

further,

The major axis a2 of the oval groove 5 is 22 mm, and the minor axis b2 is 21.07 mm.

further,

As shown in FIG. 3 , the length L3 of the rectangular patch 1 is 15 mm, and the width W3 is 1.85 mm.

further,

The projection angle between the major axis of the elliptical slot 5 and the microstrip feeder 2 is 45 degrees;

further,

The included angle between the long axis of the elliptical patch 1 and the microstrip feeder 2 is 45 degrees.

Fig. 1 is an overall structural diagram of a directional circularly polarized patch antenna for medical detection provided by the utility model. The antenna consists of an elliptical patch 1 , a microstrip feeder 2 , a rectangular single-layer double-sided PCB 3 and a grooved floor 4 .

FIG. 2 is a structure diagram of an elliptical patch antenna in an embodiment of the present invention, including an elliptical patch 1 , a microstrip feeder 2 and a rectangular single-layer double-sided PCB 3 .

In a specific implementation, the angle between the long axis of the elliptical patch 1 and the microstrip feeder 2 is 45 degrees. The major axis a1 of the elliptical patch 1 is 0.34 times the wavelength corresponding to the working center frequency of the antenna, a1 is 17.35 mm, b1 is 16.62 mm, and the axial ratio is 1.0438. The input impedance of the microstrip feeder is 50Ω, the length L2 is 8mm, and the width W2 is 1.82mm. The rectangular single-layer double-sided PCB board 3 is made of FR4_epoxy microwave material, the dielectric constant is 4.4, the tangent loss is 0.02, the thickness is 1mm, and the thickness of the double-sided copper clad board is 35 μm. The length L1 is 33.5 mm, and the width W1 is 40 mm.

FIG. 3 is a floor structure diagram of a groove in an embodiment of the present invention, including a hollowed out elliptical groove 5 and a rectangular patch 6 .

In a specific implementation, the projected angle between the long axis of the hollowed-out elliptical slot 5 and the microstrip feeder 2 is 45 degrees, and the area of the elliptical slot 5 is larger than the area of the elliptical patch 1 . The major axis a2 of the oval groove 5 is 22 mm, and the minor axis b2 is 21.07 mm. The length L3 of the rectangular patch 6 is 15 mm, and the width W3 is 1.85 mm.

Among them, the circular seam formed by the elliptical groove 5 and the elliptical patch 1 constitutes capacitive loading, and the coupled short circuit of the elliptical patch 1 and the rectangular patch 6 constitutes inductive loading, thereby realizing circularly polarized directional radiation within the working frequency band.

Fig. 4 is a return loss diagram of a directional circularly polarized patch antenna for medical detection provided by an embodiment of the present invention. As shown in Figure 4, the working center frequency of the antenna is 5.8GHz, the working frequency band is 5.42GHz-6.32GHz, and the absolute bandwidth reaches 0.9GHz, which meets the requirements of broadband antennas.

Fig. 5 is an electromagnetic simulation axial ratio curve diagram of a directional circularly polarized patch antenna for medical detection provided by an embodiment of the present invention. As shown in Figure 5, within the range of -4.5deg-21.0deg in the main radiation direction, the axial ratios are all less than 3dB, indicating that the circular polarization effect is better.

Fig. 6 is a gain pattern on the xz and yz sections of a directional circularly polarized patch antenna for medical detection provided by an embodiment of the present invention. As shown in Figure 6, the gain pattern on the xz section shows that the antenna has the strongest radiation along the z-axis direction, and the gain pattern on the yz section shows that the radiation of the antenna is very concentrated along the z-axis and -z-axis directions, thus indicating that The designed antenna has good directional radiation performance.

The utility model discloses a directional circularly polarized patch antenna for medical detection, which is composed of an elliptical patch 1, a microstrip feeder 2, a rectangular single-layer double-sided PCB board 3 and a grooved floor 4. The rectangular single-layer double-sided PCB board 3 is made of FR4_epoxy microwave material, and the grooved floor 4 is composed of a hollowed-out elliptical groove 5 and a rectangular patch 6 . The utility model has the characteristics of simple structure, small size, low cost and wide working frequency band. Compared with the existing circularly polarized microstrip antenna, the design adopts single-point feeding and simultaneously loads capacitance and inductance to realize directional circular poles. And it works in the 5.8GHz ISM frequency band, which can be widely used in the field of medical detection.

The utility model is applied to medical detectors in the 5.8GHz ISM frequency band or instruments and equipment that have directional requirements on the radiation direction. The utility model provides a circularly polarized patch antenna for medical detection. The circular polarization, simplification, miniaturization and directional design of the antenna are realized by loading capacitance and inductance. The performance of the antenna of the utility model is high , strong sturdiness, high practicability, and low cost. The designed antenna adopts single-point feed design, which has a simple structure and is easy to integrate. Compared with other circularly polarized microstrip antennas, no external circularly polarized feed network is required, and a relatively Good circularly polarized radiation effect. In addition, the design realizes the integrated design of the antenna and the network, and can realize the array antenna design, which is suitable for medical detection equipment requiring circularly polarized antennas.

A circularly polarized patch antenna for medical detection provided by the utility model has been introduced in detail above. For those of ordinary skill in the art, according to the idea of the utility model embodiment, in terms of specific implementation and application range There will be changes. In summary, the content of this specification should not be understood as limiting the utility model.

Claims (10)

1. a kind of for the medical circularly-polarized patch antenna for detecting, it is characterised in that including：

Ellipse patch, microstrip feed line, single-layer double-side pcb board, grooving floor；

The microstrip feed line is protruded and is connected at the ellipse patch periphery；

The grooving floor includes the oval groove, the rectangular patch that hollow out；

The rectangular patch is recessed in the oval groove；

The oval groove constitutes capacitive load with the circumferential weld that the ellipse patch is formed；

The ellipse patch and the rectangular patch coupling short constitute inductance loading.

2. according to claim 1 for the medical circularly-polarized patch antenna for detecting, it is characterised in that

The working frequency of the circularly-polarized patch antenna is 5.8GHz ISM bands.

3. according to claim 2 for the medical circularly-polarized patch antenna for detecting, it is characterised in that

The major axis a1 of the ellipse patch be the circularly-polarized patch antenna working frequency corresponding to 0.3-0.4 times of wavelength, The major axis a1 of the ellipse patch and the short axle b1 axles ratio of the ellipse patch are 1.04-1.05.

4. according to claim 3 for the medical circularly-polarized patch antenna for detecting, it is characterised in that

The single-layer double-side pcb board is FR4_epoxy microwave materials, and relative dielectric constant is 4-5, and tangent loss is 0-0.05, Thickness is 0-2mm, and the thickness of double face copper is 30-40 μm, and length L1 is 30-35mm, and width W1 is 30-50mm.

5. according to claim 4 for the medical circularly-polarized patch antenna for detecting, it is characterised in that

The input impedance of the microstrip feed line is 50 Ω, and length L2 is 8mm, and width W2 is 1.82mm.

6. according to claim 5 for the medical circularly-polarized patch antenna for detecting, it is characterised in that

Area of the area of the oval groove more than the ellipse patch.

7. it is according to claim 6 for the medical circularly-polarized patch antenna for detecting, it is characterised in that the oval groove Major axis a2 is 15-30mm, and short axle b2 is 21-22mm.

8. it is according to claim 7 for the medical circularly-polarized patch antenna for detecting, it is characterised in that the rectangular patch Length L3 be 10-20mm, width W3 be 1.6-2.0mm.

9. it is according to claim 8 for the medical circularly-polarized patch antenna for detecting, it is characterised in that the oval groove Major axis is 40-50 degree with the projection angle of the microstrip feed line.

10. it is according to claim 9 for the medical circularly-polarized patch antenna for detecting, it is characterised in that the oval patch The major axis of piece is 40-50 degree with the angle of the microstrip feed line.