A P-band wideband characteristic planar dipole antenna

Abstract

The application discloses a P-waveband broadband characteristic planar dipole antenna and belongs to the technical field of decimeter wave radio frequency front-end devices. A pair of printed planar dipoles composed of a half-elliptical part and a rectangular part and respectively located on the upper and lower surfaces of a dielectric substrate form the main radiation structure of the antenna. A metal base is composed of a metal side wall and a metal ground back plate, the metal side wall plays a role of supporting the dielectric substrate and also plays a role of a parasitic element, the current of the dipole is coupled to the parasitic element metal side wall, the current is avoided from being concentrated in the center of the dipole patch, and therefore the impedance bandwidth of the antenna is improved. The antenna has good radiation performance at 0.4 GHz, 0.5 GHz, 0.6 GHz, 0.7 GHz and 0.8 GHz, and the antenna can be widely applied to P-waveband wireless communication systems with requirements of broadband, low profile and stable performance.

Description

Technical Field

[0001] This invention relates to a P-band broadband planar dipole antenna, belonging to the field of decimeter-wave radio frequency front-end device technology. Background Technology

[0002] The P-band (frequency range 0.3GHz-1GHz), as a decimeter-wave band, possesses core characteristics such as strong electromagnetic wave diffraction capability, low atmospheric attenuation coefficient, and excellent penetration through clouds and vegetation. It has irreplaceable application value in fields such as long-range early warning radar, low-altitude emergency communication, dual-use military and civilian satellite remote sensing, and geological exploration signal transmission. For example, in border long-range early warning systems, P-band radar needs to achieve wideband coverage of 0.5GHz-1GHz to simultaneously detect both low-speed targets (such as drones) and high-speed targets (such as cruise missiles). In low-altitude communication scenarios, P-band antennas need to be adaptable to mobile platforms such as vehicles and ships, requiring miniaturized and easily integrated structural features.

[0003] Planar dipole antennas have become one of the mainstream antenna types in the P-band due to their advantages such as simple structure (composed of symmetrical conductor arms and feeding structure), low manufacturing cost (can be printed on dielectric substrates such as FR4 and PTFE), and strong compatibility with printed circuit boards (PCBs). Traditional planar dipole antennas are designed based on the half-wave resonance principle. Their basic structure includes: two parallel dipole arms (the length is usually 1 / 4 of the operating wavelength, and the total length is close to 1 / 2 wavelength), a feeding port located in the middle of the two arms (fed via coaxial line or microstrip line), and a balun (such as a microstrip balun or choke balun) for balancing-to-unbalanced signal conversion.

[0004] However, most existing P-band planar dipole antennas have narrow bandwidths in practical applications, failing to cover the diverse needs of the P-band. The resonant bandwidth of traditional half-wave planar dipole antennas is typically only 5%-15% (relative bandwidth). For example, an antenna designed for 0.8 GHz has an effective operating bandwidth of only 0.76 GHz-0.84 GHz, which cannot cover the wideband application scenarios (such as multi-band radar signal reception and cross-system communication compatibility) within the P-band (0.5 GHz-1 GHz). To achieve wideband coverage, existing technologies often employ the stacking of multiple resonant elements, significantly increasing the complexity of the antenna structure and making it prone to electromagnetic coupling between elements, leading to gain fluctuations (with fluctuation amplitudes exceeding 1.5 dBi). Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the aforementioned background technology and provide a P-band broadband planar dipole antenna. It adopts a symmetrical layout, with the antenna's metal base consisting of two metal sidewalls and a metal ground plate. This design simultaneously supports the antenna's dielectric substrate structure, reduces the antenna's profile height, optimizes the radiation pattern, and extends the antenna's impedance bandwidth during operation. Furthermore, by etching grooves into the radiating patch and placing parasitic patches around it, the antenna's impedance bandwidth is further optimized.

[0006] The objective of this invention is achieved as follows:

[0007] A broadband planar dipole antenna for the P-band includes a metal base, a dielectric substrate, a main radiating patch, a secondary radiating patch, and a feed probe.

[0008] The metal base consists of a metal back plate and side plates; two side plates are provided, each standing on top of the metal back plate; the dielectric substrate is located above the metal back plate and its two ends overlap the side plates respectively; the main radiating patch and the secondary radiating patch are located on the upper and lower surfaces of the dielectric substrate respectively; two parasitic patches are also provided on the upper and lower surfaces of the dielectric substrate; in the same plane, the two parasitic patches are located on both sides of the corresponding radiating patch, and the parasitic patches are perpendicular to the side plates;

[0009] The secondary radiation patch has a circular cutout at its center; the inner end of the main radiation patch is connected to a power feed patch, the other end of which extends above the circular cutout, the top of the power feed probe is connected to the power feed patch, and the bottom end passes through the circular cutout.

[0010] Furthermore, both the main radiating patch and the secondary radiating patch consist of two parts: a rectangular part and a semi-elliptical part. One of the long sides of the rectangular part coincides with the major axis of the semi-elliptical part, and the other long side of the rectangular part is close to and parallel to the metal base.

[0011] Furthermore, both the main radiating patch and the secondary radiating patch are provided with three parallel slots; the length of the slots on both sides is greater than the length of the middle slot; the slots are vertical and extend through to the other long side of the rectangular portion.

[0012] Furthermore, both the main radiating patch and the secondary radiating patch are provided with through holes, which are located on the minor axis of the semi-elliptical portion and close to the inner end of the radiating patch.

[0013] Furthermore, the power supply patch consists of a transmission line and a stub, which are perpendicular to each other to form a cross-shaped structure, wherein the power supply probe is connected to the end of the transmission line.

[0014] Furthermore, the metal back plate is provided with a circular through hole, which is located directly below the circular cut.

[0015] Furthermore, the ratio of the major axis to the minor axis of the indivisible semiellipse is 1.3.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. The side plate of the present invention not only supports the dielectric substrate, but also acts as a parasitic structure. When the antenna is working, the radiating patch couples a portion of the current to the side plate, which is beneficial to optimizing the impedance bandwidth of the antenna.

[0018] 2. In this invention, slots are etched on both radiating patches. The slots on the radiating patches further improve the current flow direction and density on the radiating patches when the antenna is working. At the same time, the radiating patches are coupled with the parasitic patches around the radiating patches to jointly optimize the impedance bandwidth when the antenna is working.

[0019] 3. The core advantage of this invention is that the antenna proposed in this invention achieves an ultra-wide operating frequency band of 0.396-0.941GHz, with a calculated relative bandwidth of approximately 81.5%. It not only fully covers the core range of the P-band, but also has good radiation performance at 0.4GHz, 0.5GHz, 0.6GHz, 0.7GHz and 0.8GHz. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of the overall structure of a broadband planar dipole antenna in the P-band.

[0021] Figure 2 This is a schematic diagram of the overall structure of a broadband planar dipole antenna in the P-band.

[0022] Figure 3 This is a top view of the overall structure of a P-band broadband planar dipole antenna.

[0023] Figure 4 This is a top view of the main radiating patch structure of a broadband planar dipole antenna in the P-band.

[0024] Figure 5 This is a top view of the subradiating patch structure of a broadband planar dipole antenna in the P-band.

[0025] Figure 6 This is a partial top view of the feed patch of a P-band broadband planar dipole antenna.

[0026] Figure 7 This is a top view of the main radiating patch block structure of a P-band broadband planar dipole antenna.

[0027] Figure 8This is a schematic diagram showing the relative positions of the parasitic patch and the radiating patch in a broadband planar dipole antenna for the P-band.

[0028] Figure 9 This is the gain pattern of the antenna at key frequencies in the P-band;

[0029] Figure 10 This is the impedance matching diagram S11 for the antenna.

[0030] In the diagram: 1. Metal base, 2. Dielectric substrate, 3. Parasitic patch, 4. Main radiating patch, 41. Rectangular portion, 42. Semi-elliptical portion, 5. Secondary radiating patch, 6. Power supply patch, 4-1. First side slot, 4-2. First center slot, 4-3. First through hole, 5-1. Second through hole, 5-2. Side slot, 5-3. Center slot, 5-4. Circular cutout, 6-1. Short stub, 6-2. Narrow segment, 6-3. Matching segment, 6-4. Wide segment. Detailed Implementation

[0031] The present invention will now be described in further detail.

[0032] A P-band broadband planar dipole antenna includes a metal base 1, a dielectric substrate 2, a parasitic patch 3, a main radiating patch 4, a secondary radiating patch 5, and a feed probe.

[0033] The main radiating patch 4 and the secondary radiating patch 5 are located on the upper and lower surfaces of the dielectric substrate 2, respectively. The main structure of the main radiating patch 4 is a metal patch composed of a semi-elliptical portion 42 and a rectangular portion 41. The ratio of the major axis to the minor axis of the semi-elliptical portion 42 is 1.3. The long side of the rectangular portion 41, which is combined with the semi-elliptical portion 42, has the same length as the major axis of the semi-elliptical portion 42. The major axis of the semi-elliptical portion 42 and the long side of the rectangular portion 41 are bonded together to form the radiating patch structure.

[0034] Each main radiating patch 4 has three slots and one through hole. The two longer first lateral slots 4-1 are symmetrical about the antenna axis, while the shorter middle slot 4-2 is located at the edge of the antenna's central axis. All three slots are parallel to the short side of the rectangular portion 41 of the main radiating patch 4. The first through hole 4-3 is located at the edge of the central axis of the semi-elliptical portion 42 of the main radiating patch 4. Both the first through hole 4-3 and the slots on the main radiating patch 4 serve to adjust the current path and distribution on the main radiating patch, preventing excessive current concentration in specific areas of the dipole arm (such as the junction of the rectangle and the semicircle), thereby optimizing the antenna's input impedance characteristics.

[0035] The structure of the secondary radiating patch 5 is basically similar to that of the primary radiating patch 4, except that it has a circular cutout 5-4 for the feed probe to pass through.

[0036] The main radiating patch 4 is connected to the feed patch 6. The feed patch consists of a transmission line (wide section 6-4, narrow section 6-2 and matching section 6-3) and a stub 6-1. The transmission line and the stub 6-1 together form a "cross" structure. The stub 6-1 can further optimize the impedance matching of the antenna.

[0037] The metal base 1 is composed of a metal back plate and side plates; the thickness of the metal base is 1mm.

[0038] The metal side plates of the metal base 1 are located at both ends of the metal back plate. While supporting the dielectric substrate 2, they also serve as a parasitic structure. The side plates are "Π" shaped metal structures. When the antenna is working, part of the current of the main radiating patch 4 and the secondary radiating patch 5 can be coupled to the side plates. The current will not be concentrated at the center of the main radiating patch 4 and the secondary radiating patch 5, thereby improving the impedance bandwidth of the antenna.

[0039] The metal base plate of the metal base 1 serves as a reflector for the antenna, controlling the antenna's radiation direction and helping to achieve directional radiation characteristics. At the same time, the metal base plate also provides a stable grounding reference for the antenna, which helps maintain the stability of impedance matching and further supports the antenna's broadband operating characteristics.

[0040] The metal base 1 has a circular through hole in its metal back plate, which is a reserved position for the coaxial line.

[0041] The dielectric substrate 2 is made of FR4 material with a relative permittivity of 4.4 and a thickness of 2mm. On the dielectric substrate 2, there is a hole at the concentric position of the circular cutout 5-4 of the sub-radiation patch 5 for the feed probe to pass through.

[0042] There are four parasitic patches 3, which are located on both sides of the corresponding radiating patch.

[0043] The two parasitic patches 3 on the left and right of the main radiating patch 4 are located on the upper surface of the dielectric substrate 2.

[0044] The two parasitic patches 3 on the left and right of the sub-radiation patch 5 are located on the lower surface of the dielectric substrate 2.

[0045] The following is a more detailed explanation:

[0046] Reference Figures 1 to 8 In this embodiment, the support structure and the metal backplate are combined into a whole, and the two together form the metal base 1, which not only ensures the working performance of the antenna, but also strengthens the structural strength of the antenna itself.

[0047] The main radiating patch 4 and the secondary radiating patch 5 are located on the upper and lower surfaces of the dielectric substrate, respectively. The secondary radiating patch 5 has an additional circular cutout 5-4 compared to the main radiating patch 4, which ensures that the power supply probe can power the main radiating patch 4 normally without interfering with the secondary radiating patch 5.

[0048] Compared to traditional linear dipoles, the main radiating patch 4 and the secondary radiating patch 5 are both composed of a semi-elliptical part 42 and a rectangular part 41. This hybrid shape results in a more uniform current distribution. The semi-elliptical part 42 can broaden the low-frequency current coverage range, while the rectangular part 41 optimizes the high-frequency current path, enabling the dipole to maintain an "effective radiation length" over a wide frequency range and avoiding drastic fluctuations in radiation impedance caused by frequency changes.

[0049] The radiating patch has through holes (first through hole 4-3 and second through hole 5-1). This structure can adjust the current path on the surface of the radiating patch and avoid the formation of local high impedance in areas where the current tends to concentrate, such as the junction of the semi-elliptical part 42 and the rectangular part 41. This makes the impedance more stable over a wide frequency range and reduces bandwidth loss caused by structural abrupt changes.

[0050] Each radiating patch has three parallel slots (first side slot 4-1, first center slot 4-2, side slot 5-2, and center slot 5-3). All three slots serve to disperse the current on the radiating patch. The longer first side slots 4-1 and 5-2 on the left and right sides have a greater guiding effect on the current than the shorter first center slots 4-2 and 5-3 in the center. This further optimizes the current distribution on the radiating patch and further expands the impedance bandwidth of the antenna.

[0051] There is a pair of parasitic patches 3 around the radiating patch. When the antenna is working, the parasitic patches 3 are coupled with the radiating patch. At the same time, the parasitic patches 3 and the part of the radiating patch that is separated by the long groove together form a new structure (similar to the structure of the Yagi Uda antenna). When the antenna is working, a new resonant point is generated, which further expands the impedance bandwidth of the antenna.

[0052] Figures 1 to 8 The dimensions of the structure are (in millimeters):

[0053] Structure a length = 26, structure b length = structure f length = 300, structure c length = 234, structure d length = 250, structure e length = 70, structure g length = 54, structure h length = 30, structure i length = 200, structure j length = 37.8, structure k length = 20, structure l length = 70, structure m length = 20, structure n length = 6, structure o length = 4, structure p length = 0.9, structure q length = 1.3, through hole diameter length = 10, circular cut diameter length = 4, structure r length = 250, structure s length = 290, structure t length = 80, structure u length = 20, structure v length = 70, structure w length = 232, circular through hole diameter length = 6.

[0054] Figure 9 The diagram shows the return loss curve of the antenna, which is below -10dB at key frequencies of 0.4GHz, 0.5GHz, 0.6GHz, 0.7GHz and 0.8GHz.

[0055] Figure 10 The antenna's gain pattern is shown at key frequencies in the P-band. The half-power beamwidths at 0.4GHz, 0.5GHz, 0.6GHz, 0.7GHz, and 0.8GHz are 106.5°, 118°, 115°, 121°, and 108°, respectively, which are characteristic of a wide-beam antenna.

[0056] The above is just one example. To obtain broadband planar dipole antennas with different center frequencies in the P-band, different parameters can be adjusted according to the specific implementation method to achieve different operating frequency bands.

[0057] It should be understood that the above description of the specific embodiments of this patent is merely an exemplary description provided to facilitate understanding of the patent solution by those skilled in the art, and does not imply that the scope of protection of this patent is limited to these specific examples. Those skilled in the art can obtain more specific embodiments without any creative effort by combining technical features, replacing some technical features, adding more technical features, etc., of the various examples listed in this patent, provided that they have a full understanding of the technical solution of this patent. All of these specific embodiments are within the scope of the claims of this patent, and therefore, these new specific embodiments should also be within the scope of protection of this patent.

Claims

1. A broadband planar dipole antenna for the P-band, characterized in that, It includes a metal base (1), a dielectric substrate (2), a main radiating patch (4), a secondary radiating patch (5), and a feed probe; The metal base (1) is composed of a metal back plate and side plates; there are two side plates, which are respectively placed on the top of the metal back plate; the dielectric substrate (2) is located above the metal back plate and its two ends are respectively attached to the two side plates; the main radiating patch (4) and the secondary radiating patch (5) are respectively located on the upper surface and the lower surface of the dielectric substrate (2); the upper and lower surfaces of the dielectric substrate (2) are also provided with two parasitic patches (3); in the same plane, the two parasitic patches (3) are respectively located on both sides of the corresponding radiating patch, and the parasitic patches (3) are perpendicular to the side plates; The secondary radiation patch (5) has a circular cutout (5-4) at its center; the inner end of the main radiation patch (4) is connected to a power feed patch (6), the other end of the power feed patch (6) extends above the circular cutout (5-4), the top end of the power feed probe is connected to the power feed patch (6), and the bottom end passes through the circular cutout (5-4).

2. The P-band broadband planar dipole antenna according to claim 1, characterized in that, The main radiating patch (4) and the secondary radiating patch (5) are each composed of two parts, namely a rectangular part (41) and a semi-elliptical part (42); one of the long sides of the rectangular part (41) coincides with the major axis of the semi-elliptical part (42), and the other long side of the rectangular part (41) is close to the metal base (1) and parallel to the metal base (1).

3. A broadband planar dipole antenna for the P-band according to claim 2, characterized in that, The main radiating patch (4) and the secondary radiating patch (5) are provided with three parallel slots; the length of the two side slots (4-1) is greater than the length of the middle slot (4-2); the slots are perpendicular and extend to the other long side of the rectangular part (41).

4. A broadband planar dipole antenna for the P-band according to claim 2, characterized in that, Both the main radiating patch (4) and the secondary radiating patch (5) are provided with through holes (4-3), which are located on the minor axis of the semi-elliptical portion (42) and close to the inner end of the radiating patch.

5. A P-band broadband planar dipole antenna according to claim 1, characterized in that, The power supply patch (6) consists of a transmission line and a stub (6-1). The transmission line and the stub (6-1) are perpendicular to each other to form a cross-shaped structure, wherein the power supply probe is connected to the end of the transmission line.

6. A broadband planar dipole antenna for the P-band according to claim 1, characterized in that, The metal back plate is provided with a circular through hole, which is located directly below the circular cut (5-4).

7. A P-band broadband planar dipole antenna according to claim 2, characterized in that, The ratio of the major axis to the minor axis of the semi-elliptical portion (42) is 1.3.

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