Dual-frequency dual-circularly-polarized common-aperture microstrip antenna

Abstract

At present, a multi-feed-point antenna form is mostly adopted by a dual-frequency dual-circularly-polarized common-caliber antenna, and a complex feed network needs to be added, so that the loss of a system is increased, and the cost is not favorably reduced. According to the dual-frequency dual-circularly-polarized common-caliber microstrip antenna provided by the invention, two circularly-polarized microstrip antennas working in the S frequency band and the C frequency band respectively adopt a 1: 4 ratio nested design, and the S frequency band antenna patch adopts a four-leaf boomerang-shaped design, so that the shielding effect of the S frequency band antenna on the C frequency band antenna is reduced, and the isolation characteristic between the S frequency band antenna and the C frequency band antenna is improved; the problem of signal interference between nested antennas is solved; and meanwhile, the gap of the C frequency band is rotated, and the feed strip lines of the dual-frequency-band antenna are arranged on the same layer, so that the low-cost design of the dual-frequency nested antenna is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of radar antennas, and in particular relates to a dual-frequency dual-circular polarization common-aperture microstrip antenna. Background Art

[0002] In recent years, satellite communication technology has developed rapidly. As one of the core components of satellite communication systems, antennas are responsible for transmitting and receiving electromagnetic signals. Compared with linear polarization antennas, circular polarization antennas can receive any linear polarization signal, and circular polarization signals can also be received by any linear polarization antenna. Circular polarization antennas have the advantages of stable reception, can offset the polarization rotation effect of the ionosphere, strong resistance to cloud and rain fading, and strong resistance to multipath interference, and have broad application prospects in engineering technology.

[0003] With the increasingly fierce competition for spectrum resources, in order to increase the capacity of communication systems and improve the efficiency of spectrum utilization, satellite antennas are usually required to work in a multi-frequency and multi-polarization mode. Domestic and foreign scholars have turned their attention to dual-frequency dual circularly polarized antennas. At present, dual-frequency dual circularly polarized antennas have been widely used in satellite communications, high-throughput data transmission, military communications and other fields. The implementation methods of circularly polarized microstrip antennas mainly include: single-feed circularly polarized microstrip antennas based on perturbation elements to achieve orthogonal polarization degenerate mode separation, multi-feed circularly polarized microstrip antennas with multi-point orthogonal feeding combined with circularly polarized feeding networks, and multi-element methods of circularly polarized feeding networks and multi-linearly polarized microstrip antennas. The 3dB axial ratio bandwidth of single-feed circularly polarized antennas is very narrow, and their application is limited; at present, dual-frequency dual circularly polarized common-aperture antennas mostly use multi-feed antennas, which require the addition of complex feeding networks, which not only increases the loss of the system, but also is not conducive to reducing costs. Summary of the invention

[0004] In order to overcome the shortcomings of the existing circularly polarized co-aperture antenna, the present invention proposes a dual-frequency dual circularly polarized co-aperture microstrip antenna. The co-aperture antenna uses a 1:4 ratio nested design for two circularly polarized microstrip antennas working in the S and C bands respectively, integrates the patch perturbation technology and the orthogonal slot coupling feeding technology, improves the circular polarization characteristics of the antenna, broadens the antenna 3dB axial ratio bandwidth, and solves the problem of narrow axial ratio bandwidth of circularly polarized antennas with single feed points; the S-band antenna patch adopts a four-leaf boomerang shape design to reduce the shielding effect of the S-band antenna on the C-band antenna, improve the isolation characteristics between the S / C-band antennas, and solve the problem of signal interference between nested antennas; at the same time, the C-band slot is rotated, and the feeding strip lines of the dual-band antenna are placed on the same layer, realizing the low-cost design of the dual-band nested antenna.

[0005] The dual-frequency dual-circularly polarized common-aperture microstrip antenna of the present invention comprises an S-band left-handed circularly polarized antenna and a C-band right-handed circularly polarized antenna, both of which adopt a microstrip antenna configuration of a single-feed-point slot coupling excitation mode; the orthogonal slots of the S-band left-handed circularly polarized antenna and the C-band right-handed circularly polarized antenna both comprise: an "I"-shaped slot and a "Z"-shaped slot, which are orthogonally crossed and combined; the feeding strip line is a "T"-shaped strip line, which is placed in the middle of the orthogonal slot and forms an angle of 45 degrees with the orthogonal slot, and the feeding strip lines of the S-band left-handed circularly polarized antenna and the C-band right-handed circularly polarized antenna are located in the same layer; dielectric columns are used to support the patches of the microstrip antennas; the S-band left-handed circularly polarized antenna and the C-band right-handed circularly polarized antenna are nested in a 1:4 ratio.

[0006] The S-band left-hand circularly polarized antenna is composed of a patch layer, a dielectric column, and a slot layer from top to bottom, and the dielectric column is supported between the patch layer and the slot layer; the patch layer includes an S-band microstrip antenna metal patch and a metal patch support plate, the metal patch is in the shape of a four-leaf boomerang, and is composed of a circle with a radius of R0 cut off from four circles with a radius of R1, R0>2R1; the metal patch support plate is also in the shape of a four-leaf boomerang, and is composed of a circle with a radius of R0+2mm cut off from four circles with a radius of R1, and four fixing holes are opened on the metal patch support plate, and the dielectric column supports and fixes the metal patch support plate through the fixing holes; the orthogonal slots on the slot layer are composed of an "I"-shaped slot and a "Z"-shaped slot placed orthogonally, and the feeding strip line is in the shape of a "T", and is placed at an orthogonal position between the "I"-shaped slot and the "Z"-shaped slot, and forms an angle of 45° with the orthogonal slot.

[0007] The C-band right-hand circularly polarized antenna is composed of a metal patch, a dielectric column, and a slot layer from top to bottom, and the dielectric column is supported between the metal patch and the slot layer; the C-band right-hand circularly polarized antenna is placed at the four circular positions with a radius of R1 cut off by the S-band left-hand circularly polarized antenna; the metal patch is in the shape of a ring with a radius smaller than R1, which improves the isolation between the two circularly polarized antennas; the metal patch is chamfered, and the cut is rectangular; four fixing holes are opened on the metal patch, and the dielectric column supports and fixes the metal patch through the fixing holes; the orthogonal slots on the slot layer are composed of an "I"-shaped slot and a "Z"-shaped slot placed orthogonally, and the feeding strip line is in a "T"-like shape, placed at the orthogonal position of the "I"-shaped slot and the "Z"-shaped slot, forming an angle of 45° with the orthogonal slot, and its tail is inclined at 45° to avoid interference with the dielectric column.

[0008] The beneficial effects of the present invention are

[0009] 1. Wide axial ratio bandwidth: The dual-band dual circularly polarized common-aperture antenna involved in the present invention integrates the patch perturbation technology and the orthogonal slot coupling feeding technology to improve the circular polarization characteristics of the antenna, broaden the antenna 3dB axial ratio bandwidth, and solve the technical problem of narrow axial ratio bandwidth of circularly polarized antennas with a single feed point.

[0010] 2. High isolation: The dual-band dual circularly polarized common-aperture antenna involved in the present invention has an S-band antenna patch designed in the shape of a four-leaf boomerang, which reduces the shielding effect of the S-band antenna on the C-band antenna, improves the isolation characteristics between the S / C-band antennas, and solves the problem of signal interference between nested antennas.

[0011] 3. Simple structure: The dual-band dual circularly polarized co-aperture antenna involved in the present invention, both the S and C microstrip antennas adopt a single feed point slot coupling excitation method to achieve circular polarization. Compared with the same type of co-aperture circularly polarized antennas, the structure is very simple and easy to integrate.

[0012] 4. Low processing cost: The dual-band dual circularly polarized common-aperture antenna involved in the present invention adopts a microstrip antenna structure with a single feeding point and slot coupling. The feeding networks of the S and C antennas are designed on the same layer, and the metal patches of the microstrip antenna are supported by dielectric columns, so the processing cost is low.

[0013] 5. Low profile: The dual-band dual circularly polarized common-aperture antenna involved in the present invention, both the S and C antennas are microstrip antennas, both adopt slot-coupled excitation to achieve dual circular polarization, and the profile is lower than 1 / 9λ (λ is the intermediate frequency working wavelength of the S-band antenna). BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a side view of the S / C dual-band dual circular polarization common aperture antenna of the present invention.

[0015] Figure 2 It is a top view of the S / C dual-band dual circular polarization common aperture antenna of the present invention.

[0016] Figure 3 It is a side view of the S-band antenna of the present invention.

[0017] Figure 4 FIG. 4 is a top view of the S-band antenna of the present invention.

[0018] Figure 5 It is a side view of the C-band antenna of the present invention.

[0019] Figure 6 FIG. 4 is a top view of the C-band antenna of the present invention.

[0020] Figure 7 It is a standing wave and axial ratio curve diagram of the S-band antenna of the present invention.

[0021] Figure 8 It is a standing wave and axial ratio curve diagram of the C-band antenna of the present invention.

[0022] Fig. 9 It is the intermediate frequency lobe pattern of the S-band antenna of the present invention.

[0023] Fig.10 It is the intermediate frequency lobe pattern of the C-band antenna of the present invention.

[0024] Among them, 1-S band microstrip antenna metal patch, 2-S band microstrip antenna metal patch supporting plate, 3-C band antenna metal patch, 4-S / C band antenna network layer, 5-S band antenna dielectric column, 6-C band antenna dielectric column, 7-S band antenna feeding strip line, 8-S band antenna orthogonal slot, 9-C band antenna feeding strip line, 10-C band antenna orthogonal slot 10, sl1, sl2, sl3-S band antenna orthogonal slot size, cl1, cl2, cl3, cl4-C band antenna orthogonal slot size, h, h1, h2-S / C band nested antenna profile height. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1 , Figure 2 As shown, the dual-band dual circularly polarized common-aperture microstrip antenna includes an S-band left-hand circularly polarized antenna and a C-band right-hand circularly polarized antenna; both the S-band antenna and the C-band antenna adopt a microstrip antenna structure in a slot coupling excitation mode with a single feed point, and the orthogonal slots are an orthogonal cross combination of a "I"-shaped slot and a "Z"-shaped slot; as shown Figure 4 and 6 As shown, the feeding strip line is a 'T'-shaped strip line, placed in the middle of the orthogonal slots, forming an angle of 45° with the slots, and the feeding strip lines of the S and C antennas are designed on the same layer; the patches of the microstrip antennas are supported by dielectric columns; the S-band left-handed circularly polarized antenna and the C-band right-handed circularly polarized antenna are designed with a 1:4 ratio nesting.

[0027] See also Figure 2 , Figure 3 , Figure 4The S-band left-hand circularly polarized antenna is composed of a patch layer, a support column, and a slot layer from top to bottom; in order to reduce the shielding effect of the S-band antenna on the C-band antenna, the S-band microstrip antenna metal patch 1 is designed to be in the shape of a four-leaf boomerang, which is composed of a circle with a radius of R0 and four circles with a radius of R1 cut off; similarly, the metal patch support plate 2 is designed to be in the shape of a four-leaf boomerang, which is composed of a circle with a radius of R0+2mm and four circles with a radius of R1 cut off; the metal patch support plate 2 is made of FR4_epoxy material and has four fixing holes on it, and the S-band antenna dielectric column 5 fixes the metal patch support plate 2 through the fixing holes. Support and fixation; the S-band antenna dielectric column 5 is made of Teflon material and there are 4 of them; the S-band antenna orthogonal slot 8 is composed of an "I"-shaped slot and a "Z"-shaped slot placed orthogonally, the "I"-shaped slot length is sl1, and the "Z"-shaped slot is composed of a long slot with a length of sl2 and a short slot with a length of sl3; the S-band antenna feeding strip line 7 is in the shape of a "T", placed in the middle of the slot at the orthogonal position between the "I"-shaped slot and the "Z"-shaped slot, and forming an angle of 45° with the orthogonal slot; the distance from the slot layer to the patch layer is h1, and considering the length of the dielectric column 5, the cross-sectional height of the antenna is h.

[0028] In this embodiment, some dimensions of the antenna are preferably as follows:

[0029] The large circle radius R0 of the metal patch 1 of the S-band microstrip antenna is 32.6mm; the cutting circle radius R1 of the metal patch 1 of the S-band microstrip antenna is 14.4mm; the length of the "I"-shaped gap sl1 is 36.5mm; the length of the "Z"-shaped gap sl2 is 38mm; the length of the "Z"-shaped gap sl3 is 6.7mm; the distance from the gap layer to the patch layer h1 is 9.1mm; the cross-sectional height h of the antenna is 12.2mm.

[0030] See also Figure 2 , Figure 5 , Figure 6The C-band right-hand circularly polarized antenna is composed of a metal patch, a support column, and a gap layer from top to bottom; the C-band antenna metal patch 3 is optimized to a circular ring shape, which reduces the radius of the patch, increases the physical distance between the S- and C-band antenna patches, and improves the isolation between the S- and C-bands; at the same time, the patch is chamfered, and the cut is rectangular with a length of cl4 and a width of ck4; the C-band antenna metal patch 3 is made of 0.5mm thick metal copper and has 4 fixing holes on the patch; the C-band antenna dielectric column 6 supports and fixes the C-band antenna metal patch 3 through the fixing holes; the 4 The dielectric column is made of Teflon material; the orthogonal slot 10 of the C-band antenna is composed of an "I"-shaped slot and a "Z"-shaped slot placed orthogonally, the length of the "I"-shaped slot is cl1, and the "Z"-shaped slot is composed of a long slot with a length of cl2 and a short slot with a length of cl3; the C-band antenna feeding strip line 9 is quasi-"T" shaped, placed in the middle of the slot at the orthogonal position of the "I"-shaped slot and the "Z"-shaped slot, forming an angle of 45° with the orthogonal slot, and its tail is inclined at 45° to avoid interference with the C-band antenna dielectric column 6; the distance from the slot layer to the patch layer is h2.

[0031] In this embodiment, some dimensions of the antenna are preferably as follows:

[0032] The cut corner length cl4 of the metal patch 3 of the C-band antenna is 5mm; the cut corner width ck4 of the metal patch 3 of the C-band antenna is 1.8mm; the length of the "I"-shaped gap cl1 is 14mm; the length of the "Z"-shaped gap cl2 is 12.8mm; the length of the "Z"-shaped gap cl3 is 2.3mm; the distance from the gap layer to the patch layer h2 is 6.5mm.

[0033] Figure 7 , Figure 8 The curves of standing wave and axial ratio of dual-band dual circular polarization microstrip antenna changing with frequency are given. Fig. 9 , Fig.10 The intermediate frequency lobe radiation pattern of the dual-band dual circularly polarized microstrip antenna is given. It can be seen from the figure that the S-band antenna impedance bandwidth is 14.2% and the 3dB axial ratio bandwidth is 11.8%; the C-band antenna impedance bandwidth is 13.8% and the 3dB axial ratio bandwidth is 10.4%.

[0034] It should be clear that the above contents are detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these contents. For technicians in the technical field to which the invention belongs, without departing from the concept of the present invention, several simple deductions and substitutions can be made, such as changing the four-leaf boomerang to a "cross" patch, designing the ring patch to a square patch, and designing the gap to a double "S" orthogonal gap combination, etc., which should all be regarded as belonging to the invention protection scope determined by the submitted claims.

Claims

1. A dual-frequency dual-circular polarization common-aperture microstrip antenna, characterized in that: It includes an S-band left-hand circularly polarized antenna and a C-band right-hand circularly polarized antenna, both of which adopt a microstrip antenna configuration with a single feed point slot coupling excitation mode; The orthogonal slots of the S-band left-hand circularly polarized antenna and the C-band right-hand circularly polarized antenna both include: a "I"-shaped slot and a "Z"-shaped slot, which are orthogonally crossed. The feeding strip line is a 'T'-shaped strip line, which is placed in the middle of the orthogonal slots and forms an angle of 45° with the orthogonal slots. The feeding strip lines of the S-band left-hand circularly polarized antenna and the C-band right-hand circularly polarized antenna are located on the same layer; dielectric columns are used to support the patches of the microstrip antennas; the S-band left-hand circularly polarized antenna and the C-band right-hand circularly polarized antenna are nested in a 1:4 ratio.

2. The dual-frequency dual-circular polarization co-aperture microstrip antenna according to claim 1, characterized in that: The S-band left-hand circularly polarized antenna is composed of a patch layer, a dielectric column, and a slot layer from top to bottom, and the dielectric column is supported between the patch layer and the slot layer; the patch layer includes an S-band microstrip antenna metal patch and a metal patch support plate, the metal patch is in the shape of a four-leaf boomerang, and is composed of a circle with a radius of R0 cut off from 4 circles with a radius of R1, R0>2R1; the metal patch support plate is also in the shape of a four-leaf boomerang, and is composed of a circle with a radius of R0+2mm cut off from 4 circles with a radius of R1, and 4 fixing holes are opened on the metal patch support plate, and the dielectric column supports and fixes the metal patch support plate through the fixing holes; the orthogonal slots on the slot layer are composed of an "I"-shaped slot and a "Z"-shaped slot placed orthogonally, and the feeding strip line is in the shape of a "T", and is placed at an orthogonal position between the "I"-shaped slot and the "Z"-shaped slot, and is at an angle of 45° with the orthogonal slot.

3. The dual-frequency dual-circular polarization co-aperture microstrip antenna according to claim 2, characterized in that: The C-band right-hand circularly polarized antenna is composed of a metal patch, a dielectric column, and a slot layer from top to bottom, and the dielectric column is supported between the metal patch and the slot layer; the C-band right-hand circularly polarized antenna is placed at the four circular positions with a radius of R1 cut off by the S-band left-hand circularly polarized antenna; the metal patch is in the shape of a ring with a radius smaller than R1, which improves the isolation between the two circularly polarized antennas; the metal patch is chamfered, and the incision is rectangular; four fixing holes are opened on the metal patch, and the dielectric column supports and fixes the metal patch through the fixing holes; the orthogonal slots on the slot layer are composed of an "I"-shaped slot and a "Z"-shaped slot placed orthogonally, and the feeding strip line is in a "T"-like shape, placed at the orthogonal position of the "I"-shaped slot and the "Z"-shaped slot, forming an angle of 45° with the orthogonal slot, and its tail is inclined 45° to avoid interference with the dielectric column.

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