CN115064865A

CN115064865A - Single-pulse substrate integrated waveguide collinear slot array antenna

Info

Publication number: CN115064865A
Application number: CN202210516081.5A
Authority: CN
Inventors: 靳贵平; 黄丽; 廖绍伟
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2022-05-12
Filing date: 2022-05-12
Publication date: 2022-09-16
Anticipated expiration: 2042-05-12
Also published as: CN115064865B

Abstract

The invention provides a single-pulse substrate integrated waveguide collinear slot array antenna.A first dielectric substrate is provided with a network feed structure, the network feed structure comprises a slot which is in feed coupling with a network microstrip, and the slot which is in feed coupling with the network microstrip is parallel to an H surface of the antenna; a substrate integrated collinear gap unit is arranged on the first metal layer and comprises at least one row of radiation gaps; waveguide walls are arranged on the second dielectric substrate at positions corresponding to the radiation gaps, and the radiation waveguides in the second dielectric substrate are in mirror symmetry with respect to the xoz plane; and a difference network feed structure is arranged on the third dielectric substrate and comprises a difference network microstrip feed coupling gap, and the difference network microstrip feed coupling gap is parallel to the E surface of the antenna. The cross polarization of the antenna array is reduced by arranging the collinear slot waveguide, and a single pulse network structure is realized by microstrip slot coupling feed, so that the antenna can realize sum and difference wave beams in an X frequency band, and the single pulse performance is ensured.

Description

Single-pulse substrate integrated waveguide collinear slot array antenna

Technical Field

The invention relates to the field of antennas of electronic communication technology, in particular to a single-pulse substrate integrated waveguide collinear slot array antenna.

Background

With the technology in the field of communication tracking radar becoming more mature, the waveguide slot antenna which is compact in structure and easy to process is more widely applied. The ultra-low side lobe characteristic of the waveguide slot antenna is very suitable for tracking radars carried on various aircrafts and ships, and the waveguide slot antenna is remarkably concerned in the field by combining the characteristics of light weight and small size.

The monopulse radar antenna is used as a high-precision tracking antenna, is widely applied to the military field and is used for measuring angles and distances of targets. The positioning and detection are important applications of the monopulse radar, the monopulse system radar cannot be interfered by the fading fluctuation of echoes while rapidly acquiring the amplitude-phase information of a reflected signal and a difference wave beam, the speed of acquiring the information data rate is high, and meanwhile, the monopulse system radar has certain strong anti-interference capability and is often applied to aspects of passive positioning, ground satellite communication, missile guidance and the like.

The existing method for realizing a single pulse sum difference structure based on SIW mainly comprises two methods: firstly, the magic T structure is a three-dimensional structure, the bandwidth realized by the method is wide, the traditional waveguide magic T occupies a large volume and is not beneficial to integration, and the SIW magic T has a small volume and is easier to integrate; the second is realized by a bridge phase shift method, which is a planar structure but has a narrow bandwidth.

The magic T is an important microwave power distribution and synthesis device, the waveguide magic T has the advantages of large power capacity, good port performance and the like, and Likejuan and the like provide a broadband waveguide magic T in a novel broadband waveguide magic T design [ C ]//.2021 national microwave millimeter wave conference corpus (volume below), 2021:202-204, DOI:10.26914/c.cnkihy.2021.023613, and the waveguide magic T is subjected to impedance matching by using a blending cone, a blending step and a metal diaphragm. The relative bandwidth of the waveguide reaches 47.5%, and the working frequency band of the BJ100 waveguide is completely covered. Meanwhile, the insertion loss is less than 0.1dB, and the amplitude consistency is better. Kim et al, in "protocol Ku-base dual polarization SIW monopulse antenna," Proceedings of 20143 rd Asia-Pacific Conference on Antennas and Propagation,2014, pp.565-568, doi:10.1109/APCAP.2014.6992556, propose millimeter wave monopulse Antennas based on SIW technology, the monopulse antenna arrays are integrated on a double-layer plane, and each subarray consists of 8 × 5 slot arrays of + -45 degrees. The test result shows that: at the center frequency, the maximum gain of the sum beam is up to 22dB, the first side lobe level is below-10 dB, and the maximum null depth of the difference beam is-27 dB. Liu et al, "in IEEE Transactions on Antenna and Propagation, vol.57, No.1, pp.275-279, Jan.2009, doi:10.1109/TAP.2008.2009743," propose a low-profile Ka-band SIW Monopulse Antenna, which is Integrated on a single-layer dielectric Substrate, and radiates energy through a Slot Array, and a microstrip feed is used at a port, so that the structure is compact, and the requirement of the low-profile Antenna is met.

However, the sum and difference formed by the magic T is larger than the network structure, and the magic T is difficult to process, design and manufacture and has high cost. Although the microstrip structure is not suitable for high-power transmission, the microstrip structure is relatively suitable for airborne or aerospace application with low cost due to the light and handy planar structure, for example, a 180-degree directional coupler is formed by combining an O-degree/90-degree 3dB coupler and a 90-degree phase shifter in the development of a microstrip phased-array antenna, a microstrip monopulse antenna and an MEMS phase shifter [ D ]. Nanjing university of Physician institute, 2003 ] of Cheng Guang light and the like, so that the sum-difference comparison network and the microstrip antenna array are integrated on the same plane, and the zero depth of the finally obtained monopulse antenna array is better than-25 dB in the bandwidth range, but the surface area of the antenna is too large based on the phase shifter principle, the bandwidth is relatively narrow, and the integration and the application are not facilitated.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a single-pulse substrate integrated waveguide collinear slot array antenna, cross polarization of an antenna array is reduced by arranging collinear slot waveguides, a single-pulse network structure is realized by microstrip slot coupling feeding, the structure is simplified, sum and difference beams of the antenna can be realized in an X frequency band, single-pulse performance is ensured, and the antenna is easy to integrate.

In order to achieve the purpose of the invention, the single-pulse substrate integrated waveguide collinear slot array antenna provided by the invention is sequentially provided with a first dielectric substrate, a first metal layer, a second dielectric substrate, a second metal layer and a third dielectric substrate from top to bottom,

a network feed structure is arranged on the first dielectric substrate, the network feed structure comprises a network feed port arranged on the first dielectric substrate, a network feed micro-strip and a network micro-strip feed coupling gap arranged on the first metal layer, and the network feed coupling gap is parallel to the H surface of the antenna;

a substrate integrated collinear gap unit is arranged on the first metal layer and comprises at least one row of radiation gaps, and each row of radiation gaps comprises a plurality of collinear radiation gaps;

waveguide walls are arranged on the second dielectric substrate at positions corresponding to the radiation gaps, and the radiation waveguides in the second dielectric substrate are in mirror symmetry with respect to the xoz plane;

and a difference network feed structure is arranged on the third dielectric substrate, the difference network feed structure comprises a difference network feed interface arranged on the third dielectric substrate, a difference network feed microstrip connected with the difference network feed interface and a difference network microstrip feed coupling gap arranged on the second metal layer, and the difference network microstrip feed coupling gap is parallel to the E surface of the antenna.

Further, the sum network feeding microstrip and the difference network feeding microstrip are both metal layers.

Furthermore, the materials of the first dielectric substrate, the second dielectric substrate and the third dielectric substrate are Rogers RO 4003.

Further, the dielectric constant of the first dielectric substrate, the second dielectric substrate and the third dielectric substrate is 3.55.

Further, in the substrate integrated collinear slot unit, the distance between the waveguide wall correspondingly arranged in each radiation slot and the waveguide center line is adjustable.

Further, the air conditioner is provided with a fan,

further, the microstrip feed coupling slot is a butterfly slot.

Further, the differential network microstrip feed coupling slot is a butterfly slot.

Further, the antenna includes two rows of radiating slots.

Further, the antenna can work in an X wave band of 9-10.5 GHz.

Compared with the prior art, the invention can at least realize the following beneficial effects:

1. compared with the traditional antenna with non-collinear slots, the antenna unit with the collinear slot waveguide has the advantages of low cross polarization and high gain.

2. The design of the microstrip slot coupling feed structure simplifies the structure of the traditional magic T and realizes the monopulse performance based on the SIW collinear slot antenna.

3. The electric field in the waveguide is disturbed by moving the position of the waveguide wall relative to the central line of the waveguide, so that collinear slot waveguide is realized, the cross polarization of the antenna array is reduced, and the high-gain and low-cross polarization antenna is realized.

4. The single-pulse network structure is realized through microstrip slot coupling feed, the design of the magic T structure is greatly simplified, the antenna can realize sum and difference wave beams in an X frequency band, the single-pulse performance is ensured, and the antenna is easy to integrate.

5. The micro-strip coupling slot adopts a butterfly shape with a small middle part and narrow two sides, which can ensure that energy can be coupled to the radiation waveguide, thereby improving the radiation efficiency and expanding the bandwidth.

Drawings

Fig. 1 is an overall structure of a single-pulse substrate integrated waveguide collinear slot array antenna provided by an embodiment of the invention.

Fig. 2 is a multi-layer structure diagram of a single-pulse substrate integrated waveguide collinear slot array antenna provided by an embodiment of the present invention, where (a) is a side view, i.e., a front view, of the antenna, and (b) is a top view of the antenna.

Fig. 3 is a schematic diagram of an SIW collinear slot structure and a waveguide electric field provided in an embodiment of the present invention.

Fig. 4 is a schematic diagram of a network feed structure according to an embodiment of the present invention.

Fig. 5 is a schematic diagram of a differential network feeding structure provided by an embodiment of the present invention.

FIG. 6 is a S parameter diagram in an embodiment of the present invention.

Fig. 7 is a schematic diagram of isolation S21 in an embodiment of the invention.

Fig. 8 is a poor network antenna gain pattern in an embodiment of the present invention.

Fig. 9 is a network antenna gain pattern in an embodiment of the present invention.

FIG. 10 is a graph of gain patterns at 9.8GHz, 9.9GHz, 10GHz and for a network antenna in an embodiment of the invention.

Fig. 11 is a gain pattern of the time difference network antenna at 9.8GHz, 9.9GHz, 10GHz in an embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be 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 some, but not all, embodiments of the present invention. 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.

Referring to fig. 1 to 5, the single-pulse substrate integrated waveguide collinear slot array antenna provided by the present invention includes a first dielectric substrate 100, a first metal layer 200, a second dielectric substrate 300, a second metal layer 400, and a third dielectric substrate 500, which are sequentially disposed from top to bottom, and is fed by a microstrip disposed on the first dielectric substrate 100 and the third dielectric substrate 500 through slot coupling. In some embodiments of the present invention, a Rogers RO4003(tm) plate is used for all three substrates, and the dielectric constant is 3.55.

In some embodiments of the present invention, antennas are provided that are capable of operating in the X-band 9-10.5 GHz.

In some of the embodiments of the present invention, the thickness of the second dielectric substrate 300 is 1.524 mm.

Referring to fig. 1, a network feeding structure is disposed on a first dielectric substrate 100, and the network feeding structure includes a network feeding port 1 disposed on the first dielectric substrate 100, a network feeding microstrip 2 and a network microstrip feeding coupling slot 3 disposed on a first metal layer 200, and the network microstrip feeding coupling slot 3 is parallel to an H-plane of an antenna; a substrate integrated collinear gap unit is arranged on the first metal layer 200, and comprises at least one row of radiation gaps 4;

waveguide walls are arranged on the second dielectric substrate 300 at positions corresponding to the radiation slits 4, the radiation waveguides in the second dielectric substrate 300 are symmetrical with respect to the xoz mirror image, and each row of radiation slits 4 comprises a plurality of collinear radiation slits; a difference network feed structure is arranged on the third dielectric substrate 500, the difference network feed structure comprises a difference network feed interface 5 arranged on the third dielectric substrate 500, a difference network feed microstrip 6 connected with the difference network feed interface 5, and a difference network microstrip feed coupling slot 7 arranged on the second metal layer 400, and the microstrip feed coupling slot 7 is parallel to the E-plane of the antenna. The energy of the sum network is fed into the second dielectric substrate 300 through the sum network microstrip feed coupling slot 3, and the energy in the difference network is radiated through the radiation slot 4.

The waveguide has current distribution on its four walls, vertical current distribution on its narrow side and alternate converging or diverging distribution on its wide side with half-wave guide wavelength as period, and the slots must be used to radiate energy and cut current in the same direction.

In some embodiments of the present invention, in the substrate-integrated collinear slot unit, the distance between the waveguide wall of each radiation slot 4 and the waveguide center line is adjustable. According to the embodiment of the invention, the electric field distribution in the SIW is disturbed by moving the position of the waveguide wall relative to the central line, so that the SIW collinear slot antenna is realized. A schematic diagram of the structure of the substrate-integrated collinear slit unit is shown in fig. 3.

In some embodiments of the present invention, the substrate-integrated collinear slot unit is designed to have two rows of 8 radiation slots 4, although other values may be used in other embodiments. The size of the number of the two rows of 8 gaps is not large, the gain ratio is high, the conformal effect on a military radar is facilitated, the effect is better, only 4 gaps are shown in fig. 3, the medium substrate adopts Rogers RO4003(tm), the thickness of the substrate is 1.524mm, the dielectric constant is 3.55, and the loss tangent is 0.0027. The dotted line in the figure represents the center line of the waveguide, the arrow represents the current distribution of the SIW waveguide wall after moving the waveguide wall up and down relative to the center line, and it can be seen that after moving the waveguide wall, the relative position of the electric field inside the SIW is changed, and correspondingly the position of the current of the waveguide wall is also moved, and at this time, the collinear slits can cut the current in the same direction on the SIW waveguide wall, so as to form the in-phase radiation and overlap in space. In the mode, because the gaps are collinear, the cross polarization of the antenna can be reduced, the symmetry of a directional diagram is ensured, and the performance of the antenna is improved. In addition, in order to improve the gain of the SIW antenna, the distance of the waveguide wall corresponding to each slot from the center line of the waveguide can be adjusted, so that the voltage of each slot is distributed in a constant amplitude as much as possible, and higher gain can be obtained.

A series of waveguides are arranged side by side, a plurality of gaps are formed in the surfaces of the waveguides, the control is carried out through a sum-difference network, the function of a single pulse is achieved, and the antenna is a single-pulse waveguide gap antenna. The SIW collinear slot units are arranged according to 1 x 2 to form an array, the realization of single pulse is mainly realized by sum-difference network feeding, the traditional single pulse network mainly adopts a magic T structure, a plurality of researches are made in order to simplify the structure of the feeding network, the method which is usually adopted for the improved design of the magic T is to connect two waveguides at a common narrow edge of the parallel waveguides by a slot gap, and the sum-difference calculation is realized by the phase difference caused by two input signals, and the method has smaller volume but needs a longer 90-degree phase compensation line; the other method is a novel planar waveguide magic T, and the E arm and the H arm are connected through a coupling gap, so that the size and the performance are considered.

Although the planar waveguide magic T is improved on the traditional magic T, the structure is still more complicated, and the invention further simplifies the structure. The single pulse structure provided by the present invention comprises a sum-difference network, a sum network feeding structure for realizing sum network feeding is arranged on a first dielectric substrate 100, a difference network feeding structure for realizing difference network feeding is arranged on a third dielectric substrate 500, and the two-part structure is shown in fig. 4 and fig. 5, wherein the sum network feeding structure comprises a sum network feeding port 1 arranged on the first dielectric substrate 100, a sum network feeding microstrip 2 connected with the network feeding port 1, and a sum network microstrip feeding slot 3 arranged on a first metal layer 200, and the energy of the network is fed into a second dielectric substrate 300 through the sum network microstrip feeding slot 3 to feed a SIW collinear slot unit, and since the sum network feeding slot 3 is parallel to the H-plane of the antenna, the energy of the left and right sides of the second dielectric substrate 300 is in equal amplitude and in phase, similar to the H-T structure of magic T, and since the radiation waveguide in the second dielectric substrate 300 has mirror symmetry on both sides with respect to the xoz plane, the resulting sum beam is obtained. Referring to fig. 5, the difference network feeding structure for realizing difference network feeding includes a difference network feeding interface 5 disposed on the third dielectric substrate 500, a difference network feeding microstrip 6 connected to the difference network feeding interface 5, and a difference network microstrip feeding coupling slot 7 disposed on the second metal layer 400, wherein energy in the difference network feeding interface 5 is fed into the second dielectric substrate 300 through the difference network microstrip feeding slot 7 and radiated through the radiation slot 4. Because the differential network microstrip feed coupling slot 7 is parallel to the E-plane of the antenna, and the energy fed to the left and right sides of the second dielectric substrate 300 is equal in amplitude but has a phase difference of 180 degrees, the energy radiated by the radiation slot 4 is inverted to obtain a differential beam, similar to the E-T structure of the magic T. The monopulse feed structure obtained by the design does not need a phase shifter, reduces the surface area, is not too large like the three-dimensional structure of the traditional waveguide, greatly reduces the volume of the antenna, is easier to process and is easy to integrate in radar or satellite.

In some embodiments of the invention, the sum network microstrip feed coupling gap 3 and the difference network microstrip feed coupling gap 7 in the structure adopt a butterfly shape, the matching effect same as that of a common gap is realized by the butterfly shape gap with a smaller length, and meanwhile, the resonance point can be increased to expand the bandwidth.

In some embodiments of the present invention, the first dielectric substrate 100 and the third dielectric substrate 500 both employ Rogers RO4003(tm), the substrate thickness is 0.508mm, the dielectric constant is 3.55, and the loss tangent is 0.0027.

In some embodiments of the present invention, referring to fig. 6-11, simulated performance of the antenna is shown, where port 1 represents the bad network feed port and port 2 represents the net feed port. As can be seen in fig. 6, the antenna operates in the X band, where the difference network operating band is 9.63-10.38GHz and the network band is 9.45-10.02 GHz; FIG. 7 shows the isolation between the feed ports of the sum and difference network, where the isolation between the two ports is below-38 dB, the isolation is good, and the signals between the ports of the antenna are leaked little from each other, so that the mutual influence between the two ports of the antenna is avoided to a great extent, and the target positioning can be achieved better; fig. 8-9 are antenna sum and difference network beam direction gain diagrams, wherein the maximum gain of the sum network reaches 14.2dBi, the side lobe is lower than-13 dBi, the maximum gain of the difference network is 9.6dBi, the zero depth is-14.7 dBi, the side lobe is lower than-9.3 dBi, and the side lobe of the sum beam is very low and has higher gain, so that the monopulse antenna of the present invention has stronger anti-electromagnetic interference capability and better sensitivity, and can be well applied to military radars for target orientation; the transformation of the directional diagram and the difference beam is realized by controlling the transformation of the feed port, and the directional diagram can meet the basic requirement of the single-pulse antenna; FIG. 10 is a gain pattern of a network antenna at multiple frequency points, and it can be seen from the figure that the gain of the antenna sum beam is higher and the side lobe is low at 9.9GHz and 10GHz, which basically meet the requirement of a monopulse antenna, and the gain starts to decrease and the side lobe rises at 9.8 GHz; fig. 11 is a gain directional diagram of a difference network antenna at multiple frequency points, and it can be known from the diagram that beams of the antenna at three frequency points are symmetrical, the zero depth is more than-11.9 dBi, and the sum and difference beams of the three frequency points are symmetrical, so that a single-pulse function can be realized in practical application, and the requirement is met.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The single-pulse substrate integrated waveguide collinear slot array antenna is characterized in that a first dielectric substrate (100), a first metal layer (200), a second dielectric substrate (300), a second metal layer (400) and a third dielectric substrate (500) are sequentially arranged from top to bottom,

a network feed structure is arranged on the first dielectric substrate (100), the network feed structure comprises a network feed port (1) arranged on the first dielectric substrate (100), a network feed micro-strip (2) and a network micro-strip feed coupling gap (3) arranged on the first metal layer (200), and the network micro-strip feed coupling gap (3) is parallel to the H surface of the antenna;

a substrate integrated collinear gap unit is arranged on the first metal layer (200), the substrate integrated collinear gap unit comprises at least one row of radiation gaps (4), and each row of radiation gaps (4) comprises a plurality of collinear radiation gaps;

waveguide walls are arranged on the second dielectric substrate (300) at positions corresponding to the radiation slits (4), and the radiation waveguides in the second dielectric substrate (300) are mirror-symmetrical about the xoz plane;

a difference network feed structure is arranged on the third dielectric substrate (500), the difference network feed structure comprises a difference network feed interface (5) arranged on the third dielectric substrate (500), a difference network feed microstrip (6) connected with the difference network feed interface (5) and a difference network microstrip feed coupling slot (7) arranged on the second metal layer (400), and the difference network microstrip feed coupling slot (7) is parallel to the E surface of the antenna.

2. A monopulse substrate integrated waveguide collinear slot array antenna according to claim 1, wherein the sum network feed microstrip (2) and the difference network feed microstrip (6) are both metal layers.

3. A single-pulse substrate integrated waveguide collinear slot array antenna according to claim 1, wherein the first dielectric substrate (100), the second dielectric substrate (300) and the third dielectric substrate (400) are all made of Rogers RO 4003.

4. The single-pulse substrate integrated waveguide collinear slot array antenna according to claim 1, wherein the dielectric constant of the first dielectric substrate (100), the second dielectric substrate (300), and the third dielectric substrate (400) is 3.55.

5. A single-pulse substrate integrated waveguide collinear slot array antenna according to claim 1, wherein in the substrate integrated collinear slot unit, the distance between the waveguide wall of each radiation slot (4) and the waveguide center line is adjustable.

6. A single-pulse substrate integrated waveguide collinear slot array antenna according to claim 1, wherein the microstrip feed coupling slot (3) is a butterfly slot.

7. A single-pulse substrate integrated waveguide collinear slot array antenna according to claim 1, wherein the differential network microstrip feed coupling slot (7) is a butterfly slot.

8. A single-pulse substrate integrated waveguide collinear slot array antenna according to claim 1, characterized in that the antenna comprises two rows of radiating slots (4).

9. A single-pulse substrate integrated waveguide collinear slot array antenna according to claim 8, wherein each row of radiating slots (4) comprises 4 collinear radiating slots.

10. The single-pulse substrate integrated waveguide collinear slot array antenna of any one of claims 1 to 9, wherein the antenna is capable of operating in the X-band of 9-10.5 GHz.