A broadband circularly polarized array element suitable for AOP millimeter wave phased array

Abstract

The present invention discloses a broadband circular polarization array element suitable for AOP millimeter wave phased array, which is composed of a millimeter wave radiation patch, a dielectric layer and a bottom floor; the millimeter wave radiation patch is located at the center of the upper surface of the dielectric layer; the bottom floor is located on the lower surface of the dielectric layer, and a rectangular gap structure, a rectangular microstrip feeder and a BGA ball planting structure are provided on the bottom floor; the millimeter wave radiation patch is connected to the rectangular microstrip feeder of the bottom floor through a metal through hole inside the dielectric layer. The array element is interconnected with the radio frequency front end through the BGA ball planting structure based on the AOP technology, and has the characteristics of low loss, light weight, low cost, etc.; at the same time, it overcomes the disadvantage of the narrow bandwidth of the traditional microstrip antenna and solves the technical problems of low profile and wide coverage of the existing satellite-borne phased array elements.

Description

Technical Field

[0001] The present invention relates to a satellite-borne phased array antenna technology applied in the field of satellite Internet communications, and in particular to a broadband circularly polarized array element applicable to an AOP phased array. Background Art

[0002] Satellite-borne phased array antenna technology has always been a research hotspot in the field of satellite Internet communications. With the popularization of commercial applications of satellite mobile communication systems in the civilian field and the sharp increase in the number of users, broadband large-capacity communications, high-speed data transmission and wide-area coverage have become the mainstream trends in the development of satellite communications. Compared with traditional single satellites, high-volume satellite Internet constellation systems are more complex, and the millimeter-wave payload is extremely sensitive to the electromagnetic environment, which puts higher requirements on satellite-borne antennas, which are called "satellite lifelines". Designing satellite-borne multi-beam phased array antennas with extremely low profiles and broadband characteristics is an important guarantee for adapting to the "one rocket, multiple satellites" high-volume satellite Internet applications.

[0003] However, there are still many theoretical problems and technical bottlenecks to build a high-gain broadband phased array antenna with an extremely low profile. First, due to the development of satellite miniaturization and the absolute reduction of satellite space resources, the envelope size of the satellite-borne antenna is strictly limited, and the demand for miniaturization and lightweight of the phased array elements is becoming increasingly urgent. Flat-plate phased array antennas have extremely low profiles, but the mainstream of satellite-borne flat-plate phased array elements is currently achieved through coaxial cables, SMP, SMA and other traditional types of connectors and millimeter wave front ends to achieve electrical interconnection, which has the disadvantages of large size, large weight, and large insertion loss. Secondly, in response to the broadband communication capacity requirements of satellite communication systems, satellite-borne antennas must have broadband functions. At present, circularly polarized antennas with broadband performance, such as waveguide antennas and multi-layer microstrip antennas, are large in weight and volume, and have high costs, and are not suitable for use on microsatellites; although the latter structure can achieve broadband communication to a large extent, it has high requirements for processing technology. At the same time, when used in a satellite-borne high and low temperature alternating environment (usually about ±90 degrees), it faces a huge risk of delamination failure due to the inconsistent thermal expansion coefficients of the multi-layer radiation medium and the intermediate bonding layer. Therefore, in order to reduce the risk of delamination failure, the use of single-layer microstrip antennas is undoubtedly a better choice. However, conventional single-layer microstrip antennas can only achieve an impedance bandwidth of about 5%, and their circular polarization bandwidth is narrower, which cannot meet the broadband requirements of satellite communications. Summary of the invention

[0004] Aiming at the application requirements of high-throughput and high-speed satellite communications, a broadband circularly polarized array element suitable for AOP millimeter-wave phased array is provided. It is a low-cost, wide-coverage, and highly reliable phased array antenna element that can be used in satellite applications. The element is based on AOP (Antenna on Package) technology and uses a BGA (Ball Grid Array, a PCB packaging method for integrated circuits using organic substrates) ball-planting structure to achieve interconnection with the RF front end. It has the characteristics of low loss, light weight, and low cost. At the same time, it overcomes the shortcomings of the narrow bandwidth of traditional microstrip antennas and solves the technical problems of low profile and wide coverage of existing satellite-borne phased array elements.

[0005] The technical solution of the present invention is: a broadband circularly polarized array element suitable for an AOP millimeter wave phased array, which is composed of a millimeter wave radiation patch, a dielectric layer and a bottom floor;

[0006] The millimeter wave radiation patch is located at the center of the upper surface of the dielectric layer;

[0007] The bottom floor is located on the lower surface of the dielectric layer, and a rectangular gap structure, a rectangular microstrip feeder and a BGA ball planting structure are provided on the bottom floor;

[0008] The millimeter wave radiation patch is connected to a rectangular microstrip feed line of the bottom floor through a metal through hole inside the dielectric layer.

[0009] Furthermore, the millimeter wave radiation patch is circular, and four rectangular grooves are cut on the edge of the patch, and the four rectangular grooves are centrally symmetrical relative to the center of the patch; an arc-shaped groove is opened on the inner side of the patch, and the groove width of the arc-shaped groove is 0.1mm~0.25mm, and the center of the arc-shaped groove coincides with the center of the patch.

[0010] Furthermore, the opening angle of the arc-shaped slot is 90 degrees to 120 degrees, and the angle between the central axis of the opening angle of the arc-shaped slot and the central axis of the long side of the rectangular microstrip feeder line is 90 degrees or -90 degrees.

[0011] Furthermore, the dielectric layer is made of radiation-resistant material.

[0012] Furthermore, the metal through hole is a metal cylinder with a diameter of 0.2 mm, the center of the contact surface between the metal through hole and the millimeter wave radiation patch deviates from the center of the millimeter wave radiation patch, and the center of the contact surface with the rectangular microstrip feeder is on the central axis of the short side of the rectangular microstrip feeder.

[0013] Furthermore, the center of the rectangular slot structure on the bottom floor coincides with the center of the rectangular microstrip feeder; the length and width of the rectangular slot structure are respectively greater than the length and width of the rectangular microstrip feeder, and the difference is a fixed value of 0.15 mm.

[0014] Furthermore, the BGA ball planting structure is located on the lower surface of the rectangular microstrip feeder, and the contact surface center of the BGA ball planting structure and the rectangular microstrip feeder and the contact surface center of the metal through hole and the rectangular microstrip feeder are symmetrical relative to the long side center axis of the rectangular microstrip feeder.

[0015] The beneficial effects of the present invention are:

[0016] 1. The phased array elements are directly interconnected with the RF front end through the BGA ball planting structure, which has the characteristics of low loss, light weight and low cost.

[0017] 2. The phased array element adopts a single-layer microstrip antenna form, which has a simple structure and low cost. It can effectively reduce the failure risk of the antenna in the high and low temperature alternating environment on board, and meet the high reliability requirements of the onboard antenna.

[0018] 3. The phased array elements excite the high-order modes of the microstrip antenna through the arc-shaped slots, breaking through the conventional microstrip degenerate mode narrowband radiation mode, and can effectively expand the bandwidth by more than 12%, meeting the wide coverage requirements of the satellite-borne phased array.

[0019] 4. The phased array elements achieve good circular polarization radiation within the working bandwidth by cutting rectangular slots on the edge of the patch. The structure is simple and meets the circular polarization characteristics requirements of satellite-borne antennas. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A side structural diagram of a broadband circularly polarized microstrip array element of a millimeter-wave AOP phased array according to an embodiment of the present invention;

[0021] Figure 2 A front structural diagram of a broadband circularly polarized microstrip array element of a millimeter-wave AOP phased array according to an embodiment of the present invention;

[0022] Figure 3 A simulated standing wave ratio curve of a broadband circularly polarized microstrip array element of a millimeter wave AOP phased array according to an embodiment of the present invention;

[0023] Figure 4 A simulated gain-frequency curve of a broadband circularly polarized microstrip array element of a millimeter-wave AOP phased array according to an embodiment of the present invention;

[0024] Figure 5 A simulated axial ratio-frequency curve of a broadband circularly polarized microstrip array element of a millimeter-wave AOP phased array according to an embodiment of the present invention;

[0025] Figure 6 A simulated radiation pattern of a broadband circularly polarized microstrip array element of a millimeter-wave AOP phased array at 27.8 GHz according to an embodiment of the present invention;

[0026] Figure 7A simulated radiation pattern of a broadband circularly polarized microstrip array element of a millimeter-wave AOP phased array at 28.8 GHz according to an embodiment of the present invention;

[0027] Figure 8 A simulated radiation pattern of a broadband circularly polarized microstrip array element of a millimeter-wave AOP phased array at 31.4 GHz according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0029] like Figure 1 and Figure 2 As shown, a broadband circularly polarized microstrip array element of a millimeter wave AOP phased array includes a millimeter wave radiation patch 1, a dielectric layer 2 and a bottom floor 3. The millimeter wave radiation patch 1 is circular with a radius of 1.1 mm, and four rectangular grooves 101, 102, 103, and 104 with a size of 0.8 mm*0.2 mm are cut on the edge of the patch, which are centrally symmetrical relative to the center of the patch. The millimeter wave radiation patch 1 has an arc groove 11 with a radius of 0.6 mm, a width of 0.15 mm, and an angle of 96 degrees. The center of the arc groove 11 coincides with the center of the millimeter wave radiation patch 1, and the central axis of the angle is 90 degrees to the central axis of the long side of the rectangular microstrip feed line 32. The dielectric layer 2 is made of radiation-resistant material with a dielectric constant of 3.47, with a size of 5.1 mm*5.1 mm*1 mm, and a metal through hole 21 with a radius of 0.1 mm is provided inside to connect the millimeter wave radiation patch 1 and the bottom floor 3. The center of the contact surface between the metal through hole 21 and the millimeter wave radiation patch 1 deviates from the center of the millimeter wave radiation patch 1 by 0.2 mm. The bottom floor 3 is located on the lower surface of the dielectric layer 2, and a rectangular gap structure 31, a rectangular microstrip feed line 32 and a BGA ball planting structure 33 are provided on the bottom floor 3. The size of the rectangular gap structure 31 is 0.8mm*2.8mm, the size of the rectangular microstrip feed line 32 is 0.5mm*2.5mm, and the center of the rectangular gap structure 31 coincides with the center of the rectangular microstrip feed line 32. The BGA ball planting structure 33 is a metal hemisphere with a radius of 0.5mm, which is located on the lower surface of the rectangular microstrip feed line 32, and the center of the contact surface between the BGA ball planting structure and the rectangular microstrip feed line and the center of the contact surface between the metal through hole 21 and the rectangular microstrip feed line 32 are symmetrical relative to the central axis of the long side of the rectangular microstrip feed line 32.

[0030] Based on the above design scheme, the corresponding simulation results are given below. Figure 3-8The simulated standing wave ratio curve, simulated gain-frequency curve, simulated axial ratio-frequency curve, 27GHz simulated radiation pattern, 28.8GHz simulated radiation pattern, and 31.2GHz simulated radiation pattern of the antenna are shown respectively. It can be seen that the phased array element is a single-layer microstrip structure with an envelope size of 5.1mm*5.1mm*1mm. It is directly interconnected with the RF front end through a BGA ball planting structure, and has the characteristics of simple structure, low profile, light weight and low cost. And it achieves VSWR <1.5 in the full frequency band of 27.8GHz-31.4GHz, gain greater than 6db, axial ratio less than 5dB, and can perform effective circularly polarized high-gain radiation within a working bandwidth of more than 12%, meeting the requirements of low profile, wide coverage and high reliability of satellite-borne antennas for high-throughput and high-speed satellite communication applications.

[0031] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A broadband circularly polarized array element suitable for an AOP millimeter wave phased array, characterized in that: It consists of a millimeter wave radiation patch, a dielectric layer and a bottom floor; The millimeter wave radiation patch is located at the center of the upper surface of the dielectric layer; The bottom floor is located on the lower surface of the dielectric layer, and a rectangular gap structure, a rectangular microstrip feeder and a BGA ball planting structure are provided on the bottom floor; The millimeter wave radiation patch is connected to the rectangular microstrip feed line of the bottom floor through the metal through-hole inside the dielectric layer; The center of the rectangular slot structure on the bottom floor coincides with the center of the rectangular microstrip feeder; the length and width of the rectangular slot structure are respectively greater than the length and width of the rectangular microstrip feeder, and the difference is a fixed value of 0.15 mm; The BGA ball planting structure is located on the lower surface of the rectangular microstrip feeder, and the contact surface center of the BGA ball planting structure and the rectangular microstrip feeder and the contact surface center of the metal through hole and the rectangular microstrip feeder are symmetrical relative to the long side center axis of the rectangular microstrip feeder.

2. The broadband circularly polarized array element suitable for an AOP millimeter wave phased array according to claim 1, characterized in that: The millimeter wave radiation patch is circular, and four rectangular grooves are cut on the edge of the patch, and the four rectangular grooves are centrally symmetrical relative to the center of the patch; an arc-shaped groove is opened on the inner side of the patch, and the groove width of the arc-shaped groove is 0.1mm~0.25mm, and the center of the arc-shaped groove coincides with the center of the patch.

3. The broadband circularly polarized array element suitable for an AOP millimeter wave phased array according to claim 2, characterized in that: The opening angle of the arc-shaped slot is 90 degrees to 120 degrees, and the included angle between the central axis of the opening angle of the arc-shaped slot and the central axis of the long side of the rectangular microstrip feeder line is 90 degrees or -90 degrees.

4. The broadband circularly polarized array element suitable for an AOP millimeter wave phased array according to claim 1, characterized in that: The dielectric layer is made of radiation-resistant material.

5. A broadband circularly polarized array element suitable for an AOP millimeter wave phased array according to claim 1 or 4, characterized in that: The metal through hole is a metal cylinder with a diameter of 0.2 mm. The center of the contact surface between the metal through hole and the millimeter wave radiation patch deviates from the center of the millimeter wave radiation patch, and the center of the contact surface with the rectangular microstrip feeder is on the central axis of the short side of the rectangular microstrip feeder.

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