CN221727442U - Compact low-orbit satellite antenna - Google Patents

Abstract

The utility model discloses a compact low-orbit satellite antenna, which comprises a four-arm spiral antenna body, a feed PCB and a radio frequency output port, wherein the four-arm spiral antenna body is arranged on the feed PCB; the four-arm spiral antenna body is wound into a cylinder shape and comprises a first dielectric substrate and four radiation arms; the four radiation arms have the same shape and are sequentially arranged at intervals of 90 degrees around the axis of the cylinder; the length of each radiation arm is one quarter of the working wavelength, and the radiation arm is coiled into a spiral shape through four times of bending, and comprises a first metal circuit, a second metal circuit, a third metal circuit, a fourth metal circuit and a fifth metal circuit which are sequentially connected from outside to inside; a feed column and a short-circuit column are arranged at the bottom edge of the first metal circuit; the feed PCB comprises a second medium base material and a feed network; the feed network comprises four signal ports and four grounding ports; the four radiating arms are sequentially connected with four signal ports through respective feed columns and are sequentially connected with four grounding ports through respective short-circuit columns; the technical effects of circular polarization, miniaturization, light weight and wide lobe are achieved.

Description

Compact low-orbit satellite antenna

Technical Field

The utility model relates to a satellite antenna, in particular to a compact low-orbit satellite antenna, and belongs to the technical field of satellite communication antennas.

Background

In recent years, the internet of things of the low-orbit satellite has absolute advantages in terms of power consumption, time delay, cost and the like, and compared with the communication of the medium-high-orbit satellite, the low-orbit satellite has the advantages of small satellite-ground delay, small path loss, miniaturized terminal and the like, and a microstrip antenna, a ceramic antenna, a quadrifilar helix antenna or the like are generally adopted as the low-orbit satellite communication antenna. The microstrip antenna and the ceramic antenna have the technical problems of narrow beam width, narrow bandwidth of standing wave, lower gain of low elevation angle and the like, and the overall performance is poor when the microstrip antenna and the ceramic antenna are used for low-orbit satellite communication; while a quadrifilar helix antenna generally has a wider circularly polarized radiation beam, with some gain at low elevation angles. Thus, the prior art generally employs a quadrifilar helical antenna for low orbit satellite communications.

But aiming at a low-orbit satellite antenna with the working frequency band of about 400Mhz, most of the low-orbit satellite antenna is a linear polarization antenna, the other low-orbit satellite antenna is a microstrip medium antenna, and the other low-orbit satellite antenna is rarely provided with a four-arm spiral antenna. Moreover, the antenna patterns of the linear polarized antennas are all radiated towards the surroundings, and are not suitable for low-orbit satellite transmission because of the small energy radiated from the top; in order to meet the requirement of 400Mhz, which is a particularly low frequency, the microstrip dielectric antenna is not a preferred choice because it is not only large in size, heavy in weight, inconvenient to use, but also cannot meet the requirement of low-profile radiation characteristics after being made into a circularly polarized antenna.

In summary, under the premise of ensuring higher performance indexes, the circularly polarized antenna must have the characteristics of low cost, compact structure and small volume, and therefore, a brand new quadrifilar helical antenna needs to be developed and designed to adapt to the application requirement of the frequency around 400 MHz.

Disclosure of Invention

In view of the above-mentioned existing technical problems, an object of the present utility model is to provide a compact low-orbit satellite antenna with circular polarization, miniaturization, light weight, and wide lobe.

In order to achieve the above purpose, the utility model provides a compact low-orbit satellite antenna, which comprises a quadrifilar helix antenna body, a feed PCB and a radio frequency output port;

The four-arm spiral antenna body is wound into a cylinder and comprises a first dielectric substrate and four radiation arms loaded on the outer surface of the first dielectric substrate; the four radiation arms have the same shape and are sequentially arranged at intervals of 90 degrees around the axis of the cylinder;

The length of each radiation arm is one quarter of the working wavelength, and the radiation arm is coiled into a spiral shape through four times of bending, and the radiation arm comprises a first metal circuit, a second metal circuit, a third metal circuit, a fourth metal circuit and a fifth metal circuit which are sequentially connected from outside to inside; a feed column and a short-circuit column are arranged at the bottom edge of the first metal circuit;

the feed PCB comprises a second dielectric substrate and a feed network loaded on the top surface of the second dielectric substrate; the feed network comprises four signal ports and four grounding ports;

The four radiating arms are sequentially connected with four signal ports of the feed network through respective feed columns, and are sequentially connected with four grounding ports of the feed network through respective short-circuit columns;

The radio frequency output port is connected with the bottom surface of the feed PCB to output radio frequency signals to the feed PCB.

In the utility model, the first metal circuit, the third metal circuit and the fifth metal circuit are mutually parallel and form a preset inclination angle with the bottom edge of the first medium substrate; the second metal circuit and the fourth metal circuit are respectively parallel to the bottom edge of the first dielectric substrate.

In the utility model, the feed network respectively carries out constant amplitude excitation on the four radiation arms through the four signal ports and respectively outputs signals with phases of 0 degree, 90 degrees, 180 degrees and 270 degrees.

In the utility model, the phase is delayed by 90 degrees in sequence clockwise to form left-hand circular polarization.

In a further aspect of the present utility model, the feed network further includes a coupler Q1, a coupler Q2 and a coupler Q3; each coupler comprises an input pin, an output pin, a coupling pin and an isolation pin;

The output pin of the coupler Q1 is respectively connected with the matching capacitor C1 and the radio frequency output port, the coupling pin of the coupler Q1 is connected with the resistor R1, the input pin of the coupler Q3 is connected with the output pin of the coupler Q2 through a microstrip line with the length of 1/4 working wavelength;

The coupling pin of the coupler Q2 is connected with a resistor R2; the coupling pin of the coupler Q3 is connected with a resistor R3;

The input pin and the isolation pin of the coupler Q3 and the input pin and the isolation pin of the coupler Q2 are sequentially connected with the four signal ports and respectively output signals with phases of 0 DEG, 90 DEG, 180 DEG and 270 deg.

In the utility model, the quadrifilar helix antenna body adopts a flexible printed circuit board.

In the utility model, one side edge of the first medium substrate is provided with a back adhesive area, and the other side edge is connected with the back adhesive area.

In the utility model, the diameter of the cylindrical shape wound by the quadrifilar helix antenna body is 70mm, and the height is 64mm.

The utility model further provides a feed PCB board which is made of Rogowski high-frequency boards.

In the utility model, the working frequency band of the antenna is 400Mhz-403Mhz, and when the elevation angle is more than or equal to 30 degrees, the gain is more than or equal to-1 dBi.

In summary, the compact low-orbit satellite antenna provided by the utility model has the characteristics of circular polarization, miniaturization, light weight and wide lobe, and has the following technical advantages compared with the existing product:

1. the radiation arm of the existing four-arm spiral antenna is bent for 1-2 times, the radiation arm is bent for 4 times, the spiral type antenna is formed by five metal lines, and the performance is improved on the basis of ensuring the compact size.

2. The feed PCB board of the utility model adopts 3 equal-amplitude 90-degree phase-shifting 3dB bridges, and combines board end phase-shifting wiring of quarter-working wavelength to synthesize a feed network which is close to equal amplitude and has phase difference of 90 degrees in sequence, thereby realizing excitation of equal amplitude to four radiation arms 12 respectively and outputting signals with phase positions of 0 degree, 90 degree, 180 degree and 270 degree respectively.

3. The loss of the conventional feed PCB adopting FR4 is relatively large, and the feed PCB adopting the Rogowski high-frequency board reduces the loss of the whole feed network and improves the efficiency and gain of the satellite antenna.

4. The main body size of the utility model is phi 70 multiplied by 64mm, the extension size of the circular polarized antenna is reduced, the whole size of the circular polarized antenna is reduced, and the application requirements of low cost, compact structure and small volume of the circular polarized antenna are met on the premise of ensuring higher performance indexes.

5. The frequency of the utility model can be covered to 400Mhz-403Mhz, and the performance requirement of the low-orbit satellite on the antenna is met, and the market gap of the four-arm spiral antenna with the working frequency band of about 400MHz is filled.

6. The utility model can realize that the minimum value of gain of 400Mhz-403Mhz is more than or equal to-1 dBi and standing wave is less than or equal to 1.8 at more than 60 degrees Theta, ensures the lobe width of an antenna directional diagram, improves the gain of low elevation angle and ensures that the antenna can meet the communication requirement of a satellite antenna in the upper hemispherical direction.

Drawings

FIG. 1 is a perspective view of the structure of the present utility model;

FIG. 2 is a top plan view of the structure of the present utility model;

fig. 3 is an expanded view of the quadrifilar helix antenna body of the present utility model;

FIG. 4 is a schematic diagram of the structure of a feed PCB in the present utility model;

FIG. 5 is a schematic circuit diagram of a feed network of the present utility model;

FIG. 6 is a primary radiation pattern when the present utility model is implemented;

FIG. 7 is a Theta 60 deg. radiation pattern as practiced by the present utility model;

FIG. 8 is a 3D radiation pattern when the utility model is implemented;

In the figure: 1. the four-arm spiral antenna body comprises a four-arm spiral antenna body 11, a first dielectric substrate 12, a radiating arm 101, a feed post 102, a short circuit post 121, a first metal circuit 122, a second metal circuit 123, a third metal circuit 124, a fourth metal circuit 125, a fifth metal circuit 13, a back glue area 2, a feed PCB 21, a second dielectric substrate 22, a feed network 224, a signal port 225, a ground port 3 and a radio frequency output port.

Detailed Description

The utility model is further described below with reference to the drawings and examples.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

It should be further noted that, if directional indications (such as front, rear, inner, outer, top, bottom … …) are included in the embodiments of the present utility model, the directional indications are merely used to explain the relative positional relationship, movement conditions, etc. between the components in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are correspondingly changed.

As shown in fig. 1-3, the present embodiment provides a compact low-orbit satellite antenna in the form of a quadrifilar helix antenna, which includes a quadrifilar helix antenna body 1, a feed PCB 2 and a radio frequency output port 3, as described in detail below.

As shown in fig. 1 and 2, the quadrifilar helix antenna body 1 is wound in a cylindrical shape, and includes a first dielectric substrate 11, and four radiating arms 12 loaded on the outer surface thereof; the four radiation arms 12 are identical in shape and size, uniformly distributed around the axis of the cylinder on the circumference formed by the first medium substrate 11, and sequentially arranged at intervals of 90 ° in the circumferential direction.

In other embodiments, as shown in fig. 2 and 3, the quadrifilar helix antenna body 1 employs a flexible printed circuit board FPC. In this way, the quadrifilar helix antenna body 1 processed by the flexible printed circuit board FPC has good mechanical property and assembly property, ensures the stability of the utility model, and is not easy to deform in the installation process.

In other embodiments, as shown in fig. 3, one side edge of the first medium substrate 11 is provided with a back adhesive area 13, and the other side edge is connected through the back adhesive area 13, so that the two side edges are fixed together after being wound into a cylinder shape.

In specific implementation, the first dielectric substrate 11 is rectangular, and has a diameter of 70mm and a height of 64mm, so that the diameter of the cylindrical shape wound by the quadrifilar helix antenna body 1 is 70mm, the height is 64mm, and the four radiation arms 12 are uniformly distributed on the outer side surface of the quadrifilar helix antenna body 1. Compared with the existing four-arm spiral antenna, the antenna has the advantages that the size is reduced, the structure is more compact, and the miniaturization of the antenna is facilitated.

As shown in fig. 3, each of the radiation arms 12 is a metal wire on the flexible printed circuit board FPC, and has a length of one quarter of an operating wavelength. And, each radiating arm 12 is wound into a spiral shape by four times of bending, and includes a first metal line 121, a second metal line 122, a third metal line 123, a fourth metal line 124 and a fifth metal line 125 which are sequentially connected from outside to inside, so that the size of the four radiating arms 12 is greatly reduced, the extension size of the four-arm spiral antenna body 1 is reduced, and the overall size of the antenna is reduced. And, the bottom side of the first metal line 121 is provided with a feeding post 101 and a shorting post 102, and extends downward beyond the bottom side of the first dielectric substrate 11.

In other embodiments, the second metal line 122 and the fourth metal line 124 are parallel to the bottom side of the first dielectric substrate 11, respectively. The first metal line 121, the third metal line 123, and the fifth metal line 125 are parallel to each other and form a preset inclination angle with the bottom edge of the first dielectric substrate 11, so as to implement a wide beam of the radiation pattern. For example: the predetermined inclination angle may be 80 deg. -85 deg.. The preset inclination angle may be selected according to the actual application, and is not limited herein, according to the requirements of the length of each radiating arm 12, the length of each metal line, and the height of the quadrifilar helix antenna body 1.

In particular, in order to determine the position of the radiation arm 12 where the four bends are performed, it may be required that the length of the first metal line 121 > the length of the third metal line 123 > the length of the fifth metal line 125, and the length of the second metal line 122 > the length of the fourth metal line 124. It may be further required that the gap from the first metal wiring 121 to the fifth metal wiring 125 may be the same width as the gap from the fifth metal wiring 125 to the third metal wiring 123 in the horizontal direction; in the vertical direction, the gap from the second metal line 122 to the fifth metal line 125 may be equal in height to the gap from the fifth metal line 125 to the bottom side of the first metal line 121. The specific length and width of each metal line can be adjusted according to practical situations, and are not limited herein. And, compared with the traditional four-arm helical antenna, the size of the helical radiating arm 12 formed by winding five metal lines is greatly reduced, so that the volume of the low-orbit satellite antenna is reduced.

As shown in fig. 4, the feeding PCB 2 includes a second dielectric substrate 21, and a feeding network 22 loaded on the top surface thereof; the feed network 22 includes four signal ports 224 and four ground ports 225 for providing the four radiating arms 12 with signals of equal amplitude and phase differing in sequence by 90 °.

In other embodiments, the feeding PCB 2 is made of rogers high-frequency board, so that the feeding loss of the whole feeding PCB 2 is reduced to the minimum, and the gain and efficiency of the finished antenna are improved.

In specific implementation, the second medium substrate 21 is circular, and has an outer diameter of 75mm and a height of 0.8mm; the four signal ports 224 and the four ground ports 225 are respectively uniformly distributed on the circumference of the second dielectric substrate 21, and each signal port 224 and each ground port 225 respectively correspond to one radiation arm 12.

And, the four radiating arms 12 are sequentially connected to the four signal ports 224 of the feed network 22 through respective feeding columns 101, and are sequentially connected to the four ground ports 225 of the feed network 22 through respective shorting columns 102. In a specific implementation, the feeding column 101 and the shorting column 102 of the radiating arm 12 are welded to the signal port 224 and the ground port 225 of the feeding network 22 respectively.

In other embodiments, the feeding network 22 excites the four radiating arms 12 with equal amplitude through four signal ports 224, respectively, and sequentially outputs signals with phases of 0 °, 90 °, 180 °, 270 °. In specific implementation, the feed network 22 converts the input electric signal into four feed signals with equal amplitude and sequentially different by 90 ° and provides the four feed signals to the four radiation arms 12, so that the feed phases of the four radiation arms 12 are sequentially different by 90 °, and the phases are sequentially delayed by 90 ° clockwise to form left-hand circular polarization, thereby meeting the requirement of the four-arm helical antenna for transmitting the left-hand circular polarized electromagnetic wave, and the utility model has good wide wave beam and circular polarization characteristics.

In other embodiments, as shown in fig. 4, in order to excite the left-hand circularly polarized signal, the feeding network 22 further includes a coupler Q1, a coupler Q2 and a coupler Q3, each having four pins for transmitting signals, including an input pin, an output pin, a coupling pin and an isolation pin, and other regions for grounding. Excitation with nearly constant amplitude and 90 deg. phase difference is output to the four radiating arms 12 through these three couplers, thereby realizing circular polarization.

In the implementation, as shown in fig. 5, the arrow in the figure indicates the connection relationship, the output pin of the coupler Q1 is respectively connected to the matching capacitor C1 and the radio frequency output port 3, the coupling pin is connected to the resistor R1, the resistance is 51 ohms, the input pin is connected to the output pin of the coupler Q3, and the isolation pin is connected to the output pin of the coupler Q2 through a microstrip line with a length of 1/4 of the operating wavelength. The coupling pin of the coupler Q2 is connected with a resistor R2, and the resistance value is 51 ohms. The coupling pin of the coupler Q3 is connected with a resistor R3, and the resistance value is 51 ohms. The input pin and the isolation pin of the coupler Q3, and the input pin and the isolation pin of the coupler Q2 are sequentially connected to the four signal ports 224, and output signals with phases of 0 °, 90 °, 180 °, and 270 ° respectively.

The feed PCB 2 can excite the four radiating arms 12 of the four-arm helical antenna 1 to have equal amplitude, and the phases output through the four signal ports 224 lag by 90 ° in turn clockwise, so that the four radiating arms 12 emit the left-hand circularly polarized electromagnetic wave.

As shown in fig. 1 and 2, the radio frequency output port 3 is connected to the bottom surface of the feeding PCB 2, and is configured to output a radio frequency signal to the feeding PCB 2. In implementation, the rf output port 3 is connected to the output pin of the coupler Q1.

In summary, the compact low-orbit satellite antenna provided by the above embodiment adopts the four-arm spiral antenna body 1 provided with four spiral radiation arms 12, and is matched with three equal-amplitude 90-degree phase-shifting 3dB bridges, and the plate end phase-shifting routing of quarter-division working wavelength is added to synthesize the feed network 22 which is close to equal-amplitude and has the phase difference of 90 degrees in sequence, so that the sizes of the four-arm spiral antenna body 1 and the feed PCB 2 are greatly reduced, the circular polarization characteristic of the four-arm spiral antenna is obtained, the size of the four-arm spiral antenna is reduced, the performance of the four-arm spiral antenna is improved, the main size is phi 70 x 64mm, the working frequency band is 400Mhz-403Mhz, and the left-hand circular polarization gain is more than or equal to-1 dBi when the elevation angle is more than or equal to 30 degrees.

The present utility model was tested as follows, the main radiation pattern of the present utility model is shown in fig. 6, the Theta 60 deg. radiation pattern is shown in fig. 7, the 3D radiation pattern is shown in fig. 8, and the corresponding performance parameter measurements are shown in table 1.

TABLE 1

As can be seen from Table 1, the operating frequency range of the utility model is 400Mhz-403Mhz, which meets the performance index of the low-orbit satellite antenna. As can be seen from the combination of FIG. 6 and FIG. 7, in the operating frequency range of 400Mhz-403Mhz, the gain peak of the utility model is basically above 3dBi, even at Theta 60 DEG, the minimum value of the left-hand circular polarization gain is above-1 dBi, the standing wave is less than or equal to 1.8, and the utility model is superior to the performance parameters of the common antenna, and has good wide beam characteristics and left-hand circular polarization performance. As can be seen from the combination of FIG. 8, the antenna pattern of the present utility model has uniform radiation, ensures the lobe width of the antenna pattern and improves the low elevation gain on the basis of ensuring the compact size, so that the antenna can meet the communication requirement of the satellite antenna in the upper hemispherical direction.

Furthermore, while the principles of the utility model have been described in detail in connection with the preferred embodiments, it should be understood by those skilled in the art that the foregoing embodiments are illustrative of only and are not limiting of the scope of the utility model. The details of the embodiments are not to be taken as limiting the scope of the utility model, and any obvious modifications based on equivalent changes, simple substitutions, etc. of the technical solution of the utility model fall within the scope of the utility model without departing from the spirit and scope of the utility model.

Claims (10)

1. The compact low-orbit satellite antenna is characterized by comprising a four-arm spiral antenna body, a feed PCB and a radio frequency output port;

The four-arm spiral antenna body is wound into a cylinder and comprises a first dielectric substrate and four radiation arms loaded on the outer surface of the first dielectric substrate; the four radiation arms have the same shape and are sequentially arranged at intervals of 90 degrees around the axis of the cylinder;

The length of each radiation arm is one quarter of the working wavelength, and the radiation arm is coiled into a spiral shape through four times of bending, and the radiation arm comprises a first metal circuit, a second metal circuit, a third metal circuit, a fourth metal circuit and a fifth metal circuit which are sequentially connected from outside to inside; a feed column and a short-circuit column are arranged at the bottom edge of the first metal circuit;

the feed PCB comprises a second dielectric substrate and a feed network loaded on the top surface of the second dielectric substrate; the feed network comprises four signal ports and four grounding ports;

The four radiating arms are sequentially connected with four signal ports of the feed network through respective feed columns, and are sequentially connected with four grounding ports of the feed network through respective short-circuit columns;

The radio frequency output port is connected with the bottom surface of the feed PCB to output radio frequency signals to the feed PCB.

2. The compact low-orbit satellite antenna according to claim 1, wherein the first metal wire, the third metal wire and the fifth metal wire are parallel to each other and form a predetermined inclination angle with the bottom edge of the first dielectric substrate; the second metal circuit and the fourth metal circuit are respectively parallel to the bottom edge of the first dielectric substrate.

3. The compact low-orbit satellite antenna according to claim 1, wherein the feed network excites the four radiating arms with equal amplitude through four signal ports, and outputs signals with phases of 0 °, 90 °, 180 °, 270 °, respectively.

4. A compact low-orbit satellite antenna according to claim 3, wherein the phases are sequentially delayed by 90 ° in a clockwise direction to form a left-hand circular polarization.

5. A compact low-orbit satellite antenna according to claim 3 or 4, wherein the feed network further comprises a coupler Q1, a coupler Q2 and a coupler Q3; each coupler comprises an input pin, an output pin, a coupling pin and an isolation pin;

The output pin of the coupler Q1 is respectively connected with the matching capacitor C1 and the radio frequency output port, the coupling pin of the coupler Q1 is connected with the resistor R1, the input pin of the coupler Q3 is connected with the output pin of the coupler Q2 through a microstrip line with the length of 1/4 working wavelength;

The coupling pin of the coupler Q2 is connected with a resistor R2; the coupling pin of the coupler Q3 is connected with a resistor R3;

The input pin and the isolation pin of the coupler Q3 and the input pin and the isolation pin of the coupler Q2 are sequentially connected with the four signal ports and respectively output signals with phases of 0 DEG, 90 DEG, 180 DEG and 270 deg.

6. The compact low-orbit satellite antenna according to claim 1, wherein the quadrifilar helix antenna body comprises a flexible printed circuit board.

7. The compact low-orbit satellite antenna according to claim 1, wherein one side of the first dielectric substrate is provided with a back adhesive region and the other side is connected by the back adhesive region.

8. A compact low-orbit satellite antenna according to claim 1, 6 or 7, wherein the diameter of the cylindrical shape into which the quadrifilar helix antenna body is wound is 70mm and the height is 64mm.

9. The compact low-orbit satellite antenna according to claim 1, wherein the feed PCB is formed from rogers high-frequency board.

10. A compact low-orbit satellite antenna according to any of claims 1, 2, 3, 4, 6, 7 and 9, wherein the operating band of the antenna is 400Mhz-403Mhz, and the gain is not less than-1 dBi at an elevation angle not less than 30 °.