A method for suppressing pattern distortion of an ultra-wideband vivaldi antenna

Abstract

The application provides a method for inhibiting distortion of a VIVALDI antenna pattern of an ultra-wideband, and relates to the field of mobile communication antennas. Two horizontal slots are loaded on a metal radiation surface, one is a long slot, which is used for prolonging the path of an edge current, so that the antenna can be miniaturized to a certain extent, the length of the long slot is 75-90 mm, the width of the long slot is 3-5 mm, and the loading specific position is located at h12 above an antenna resistance loading slot, h12 is 7-12 mm; the other is a short slot which is opened on a current radiation slot of the antenna, and the loading specific position is located at h11 above the antenna resistance loading slot, h11 is 12-22 mm. The length of the short slot is 5-15 mm, and the width of the short slot is 3-5 mm. The application solves the distortion of the antenna pattern in a frequency band, and also has a certain improvement on the standing wave of the antenna.

Description

Technical Field

[0001] This invention relates to the field of mobile communication antennas, and more specifically to a method for suppressing pattern distortion in ultra-wideband VIVALDI antennas. Background Technology

[0002] With the continuous advancement of communication technology and the continuous improvement of communication speed, the advantages of ultra-wideband antennas are becoming increasingly prominent. With its ultra-wide coverage frequency, ultra-wideband antennas can meet the requirements of multiple operating frequency bands and can achieve integrated transmission and reception, which has high practical value for the increasingly complex communication systems.

[0003] However, the radiation pattern distortion problem of ultra-wideband antennas has always existed. Due to their ultra-wideband bandwidth, local current resonances inevitably occur within the frequency band, which in turn affects the antenna's radiation pattern, leading to a certain decrease in radiation performance. Therefore, solving the radiation pattern distortion problem of ultra-wideband antennas is currently a hot topic in the field of ultra-wideband antenna research. Summary of the Invention

[0004] To address the pattern distortion problem of ultra-wideband (UWB) VIVALDI antennas and meet the needs of practical engineering applications, this invention proposes a method to suppress UWB VIVALDI antenna pattern distortion. Compared to traditional methods for addressing UWB VIVALDI antenna distortion—such as slotting the antenna edge, adding directors, increasing parasitic structures, and changing the ground plane size—this invention proposes a novel distortion reduction method: slotting the antenna's radiating current slot line to alter the antenna's radiating current. Simulation results show that this method can significantly solve the pattern distortion problem within the antenna's frequency band and also improves the antenna's standing wave ratio (VSWR). For dual-polarized antennas, it improves the two-port isolation and VSWR, and also increases the maximum gain.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for suppressing pattern distortion in an ultra-wideband (UWB) VIVALDI antenna involves loading two horizontal slots onto the antenna's metallic radiating surface to form an antenna metallic surface. The two horizontal slots are a long horizontal slot and a short horizontal slot. The long horizontal slot has a length of 75-90 mm and a width of 3-5 mm. The short horizontal slot has a length of 5-15 mm and a width of 3-5 mm. The long horizontal slot extends the path of the edge current, enabling antenna miniaturization. The long horizontal slot is located 7-12 mm above the antenna resistance loading slot, starting from the edge of the antenna metallic surface and extending inwards towards the current radiating slot. The long horizontal slots on both sides of the antenna metallic surface are symmetrical with respect to the current radiating slot in the middle of the antenna metallic surface. The short horizontal slot is located 12-22 mm above the antenna resistance loading slot, starting from the current radiating slot inside the antenna metallic surface and extending inwards towards the edge of the antenna metallic surface. The short horizontal slots on both sides of the antenna metallic surface are symmetrical with respect to the current radiating slot.

[0007] Furthermore, the number of horizontal long slots and horizontal short slots is two for each antenna metal surface; the entire antenna body has a total of four horizontal long slots and four horizontal short slots.

[0008] Furthermore, the vertical distance between the horizontal long groove and the horizontal short groove is 5-10 mm.

[0009] Furthermore, the antenna consists of, from top to bottom, an antenna radome, a metal director, a dielectric substrate, an antenna metal surface, and a ground plane.

[0010] Furthermore, the antenna is a vertically and horizontally dual-polarized antenna.

[0011] Beneficial effects:

[0012] (1) The present invention makes a slot on the radiation current slot line of the antenna to change the radiation current of the antenna, thereby solving the distortion problem of ultra-wideband VIVALDI antenna.

[0013] (2) The present invention also improves the standing wave of the original antenna.

[0014] (3) The present invention does not affect the isolation of the antenna after slotting the antenna radiator.

[0015] (4) The present invention improves the maximum gain of the antenna to a certain extent. Attached Figure Description

[0016] Figure 1 Figure 1 shows the overall structure of the antenna of the present invention and a schematic diagram of the radiating surface before and after loading the present invention; Figure 2 shows the overall structure of the antenna; Figure 3 shows the front view of the antenna metal surface loaded with the present invention; Figure 4 shows the rear view of the antenna metal surface loaded with the present invention.

[0017] Figure 2 Standing wave ratio (SWR) curves at each port of the dual-polarized antenna before and after loading the horizontal slot;

[0018] Figure 3 Port isolation curves of dual-polarized antennas before and after loading the horizontal slot.

[0019] Figure 4 The main polarization pattern of the horizontally polarized antenna without the horizontal short slot is shown.

[0020] Figure 5 The main polarization pattern of the horizontally polarized antenna plane for loading the horizontal short slot;

[0021] Figure 6 This is a diagram showing the maximum radiation gain of the antenna. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0023] like Figure 1 As shown, the antenna involved in this invention is composed of an antenna radome 5, a metal director 6, a dielectric substrate 7, an antenna metal surface 10, and a ground plane 8 from top to bottom. The antenna involved in this invention is a vertically and horizontally dual-polarized antenna. The metal radiating surface 9 before use is fabricated into the antenna metal surface 10 using the method of this invention.

[0024] This invention involves loading two horizontal slots onto the metal radiating surface 9: a long horizontal slot 1 with a length of l1 (75-90 mm) and a width of d1 (3-5 mm); and a short horizontal slot 2 with a length of l2 (5-15 mm) and a width of d2 (3-5 mm). The long horizontal slot 1, formed by length l1 and width d1, extends the path of the edge current, allowing for a degree of antenna miniaturization. The short horizontal slot 2, formed by length l2 and width d2, is located on the current radiating slot 11 of the antenna. This is an innovation of this invention. Previous slotting methods typically placed the slots at the edges of the antenna's metal radiating surface, where the edge current is weakest, primarily aimed at adjusting and optimizing the standing wave ratio of the VAVILDI antenna, without significantly improving the radiation pattern. This invention achieves a distortion-free antenna radiation pattern by slotting the current radiating slot 11. The vertical distance between the long horizontal slot 1 and the short horizontal slot 2 is 5-10 mm.

[0025] The horizontal long slot 1 is located above the antenna resistor loading slot 13 at a position h12, where h12 is 7-12mm. The horizontal long slot 1 is oriented as follows: it starts from the edge of the antenna metal surface 10 and extends into the current radiation slot 11. The horizontal long slots 1 on both sides of the antenna metal surface 10 are symmetrical with respect to the current radiation slot 11 in the middle of the antenna metal surface 10.

[0026] The horizontal short slot 2 is located at h11 above the antenna resistor loading slot 13, where h11 is 12-22 mm. The horizontal short slot 2 is oriented as follows: it starts from the current radiation slot 11 inside the antenna metal surface 10 and extends towards the edge of the antenna metal surface 10. The horizontal short slots 2 on both sides of the antenna metal surface 10 are symmetrical with respect to the current radiation slot 11. There are two horizontal long slots 1 and two horizontal short slots 2 on each antenna metal surface 10; the entire antenna body has a total of four horizontal long slots 1 and four horizontal short slots 2.

[0027] Preferably, the slotting direction of the horizontal long slot 1 and the horizontal short slot 2 is perpendicular to the current radiation slot 11.

[0028] Preferably, the distance from one end of the horizontal long slot 1 away from the edge of the antenna metal surface 10 to the current radiation slot 11 is equal to the length l2 of the horizontal short slot 2.

[0029] The VIVALDI radiation mechanism is as follows: current flows in the direction of the index groove. If half the wavelength is greater than the width of the index groove, it radiates; otherwise, it continues to flow forward. This is also the ultra-wideband principle of VAVILDI antennas. Theoretically, it can achieve wireless bandwidth, but the actual manufacturing size will limit its bandwidth.

[0030] like Figure 2 As shown, the solid line represents the standing wave curve after loading, and the dashed line represents the standing wave curve of the unloaded horizontal groove. From Figure 2 It can be seen that after loading, the VSWR at 0.45 GHz decreased significantly to around 1.75, but there was a slight increase at 0.65 GHz. Overall, however, loading did improve the VSWR to some extent.

[0031] like Figure 3 As shown, the overall isolation of the ports increases to some extent after loading the horizontal slot, with the worst being around 37dB.

[0032] like Figure 4 As shown, there is significant distortion within the frequency band, and the direction of maximum radiation changes, affecting the antenna's performance. Figure 5 For the orientation pattern after loading the horizontal slot, compare... Figure 4 The change in radiation pattern is clearly visible, with the maximum radiation direction returning to normal.

[0033] like Figure 6As shown, the solid line represents the maximum gain curve after loading, and the dashed line represents the maximum gain curve without loading the horizontal slot. It can be seen from the image that the antenna's maximum gain increases to some extent after loading.

[0034] In summary, the horizontal slot on the current radiation slot 11 proposed in this invention has the effect of improving the radiation pattern distortion of the antenna, and also has a certain improvement on the circuit and radiation parameters.

[0035] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for suppressing pattern distortion of an ultra-wideband VIVALDI antenna, characterized in that, Two horizontal slots are loaded onto the metal radiating surface of the antenna to form the antenna metal surface. The two horizontal slots are a long horizontal slot and a short horizontal slot. Both the long horizontal slot and the short horizontal slot are non-through slots. The long horizontal slot has a length of 75-90 mm and a width of 3-5 mm. The short horizontal slot has a length of 5-15 mm and a width of 3-5 mm. The long horizontal slot is used to extend the path of the edge current, enabling the antenna to be miniaturized. The long horizontal slot is located 7-12 mm above the antenna resistor loading slot and starts from the edge of the antenna metal surface towards the inward current radiating slot. The long horizontal slots on both sides of the antenna metal surface are symmetrical with respect to the current radiating slot in the middle of the antenna metal surface. The short horizontal slot is opened on the current radiating slot of the antenna, located 12-22 mm above the antenna resistor loading slot. It starts from the inward current radiating slot of the antenna metal surface and starts from the edge of the antenna metal surface. The short horizontal slots on both sides of the antenna metal surface are symmetrical with respect to the current radiating slot. The vertical distance between the horizontal long groove and the horizontal short groove is 5-10mm; The slotting direction of the horizontal long slot and the horizontal short slot is perpendicular to the current radiation slot; the distance from the edge of the horizontal long slot away from the antenna metal surface to the current radiation slot is equal to the length of the horizontal short slot.

2. The method for suppressing pattern distortion of an ultra-wideband VIVALDI antenna according to claim 1, characterized in that, The number of horizontal long slots and horizontal short slots is two for each antenna metal surface; the entire antenna body has a total of four horizontal long slots and four horizontal short slots.

3. The method for suppressing pattern distortion of an ultra-wideband VIVALDI antenna according to claim 1, characterized in that, The antenna consists of, from top to bottom, a radome, a metal director, a dielectric substrate, a metal antenna surface, and a ground plane.

4. The method for suppressing pattern distortion of an ultra-wideband VIVALDI antenna according to claim 1, characterized in that, The antenna is a vertically and horizontally dual-polarized antenna.

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