Low-height L-shaped airborne ultrashort wave antenna

Abstract

The utility model relates to the technical field of communication antennas, in particular to a low-height L-shaped airborne ultrashort wave antenna which comprises a radio frequency connector, a grounding base and a radiation assembly, the radio frequency connector is fixedly connected to the bottom face of the grounding base, the radiation assembly is fixedly connected to the top face of the grounding base, and the radiation assembly comprises a radiator, a matching circuit and a feed piece. The matching circuit is arranged on the top face of the grounding base, the output end of the matching circuit is electrically connected with the radio frequency connector, the input end of the matching circuit is electrically connected with the first end of the feed piece, the second end of the feed piece is fixedly connected to the radiator, the connecting point of the feed piece and the radiator serves as a feed point, and the radiator is bent by 90 degrees towards the leeside. A 90-degree inclination angle is formed between the bent lower part of the radiator and the grounding base, and the vertical height of the bent lower part of the radiator is smaller than 1 / 15 of the central frequency wavelength. The antenna can meet the requirement of an aircraft on a low-height monopole antenna, and the antenna can obtain reasonable gain in a predetermined frequency band through loading the matching circuit.

Description

Technical Field

[0001] The utility model relates to the technical field of communication antennas, in particular to a low-height L-shaped airborne ultra-short wave antenna. Background Art

[0002] The monopole antenna is a mature horizontal omnidirectional antenna, which is widely used in ultra-short wave communication systems. In airborne ultra-short wave communication systems, monopole antennas of various structures are also often used.

[0003] A typical monopole antenna is in a vertical position relative to the ground plane. Due to the requirements of aircraft flight aerodynamics, when used as an airborne antenna, the monopole antenna has an inclination angle relative to the flight direction of the aircraft, but the maximum inclination angle generally does not exceed 40 degrees. The height of the monopole antenna with an inclination angle is generally not less than 70% of the 1 / 4 wavelength of the corresponding working frequency; when the inclination angle is large, due to the influence of the asymmetry of the ground plane relative to the antenna, the antenna will have an inclination angle in the pitch direction, affecting the gain in the flight direction. At the same time, the working bandwidth of the antenna will become narrower. When it is necessary to meet the broadband requirement, a wider and thicker antenna radiator is required, such as the commonly used knife-shaped antenna. Although the knife-shaped antenna has the advantage of a wider working bandwidth, the radiator is thicker and an antenna jacket is required to protect the radiator, so it is heavy and is not suitable for certain occasions with weight restrictions.

[0004] Based on this, there is an urgent need for an airborne ultra-short wave antenna that can meet both the low altitude and working bandwidth requirements. Utility Model Content

[0005] The purpose of the utility model is to provide a low-height L-shaped airborne ultra-short wave antenna, in which the radiator is bent into an L shape so that the vertical height of the bent lower part of the radiator is less than 1 / 15 of the wavelength of the center frequency, so as to meet the requirements of the aircraft for a low-height monopole antenna, and by loading a matching circuit, the antenna can be better matched within a predetermined frequency band and ensure a reasonable gain, thereby solving the problems pointed out in the background technology.

[0006] The embodiment of the utility model is realized by the following technical scheme: a low-height L-shaped airborne ultra-short wave antenna, comprising a radio frequency connector, a ground base and a radiation component, wherein the radio frequency connector is fixedly connected to the bottom surface of the ground base, the radiation component is fixedly connected to the top surface of the ground base, the radiation component is composed of a radiator, a matching circuit and a feeding plate, the matching circuit is arranged on the top surface of the ground base, the output end of the matching circuit is electrically connected to the radio frequency connector, the input end of the matching circuit is electrically connected to the first end of the feeding plate, the second end of the feeding plate is fixedly connected to the radiator, the connection point between the feeding plate and the radiator serves as a feeding point, the radiator is bent 90° toward the leeward side, the bent lower part of the radiator forms a 90° inclination angle with the ground base, and the vertical height of the bent lower part of the radiator is less than 1 / 15 of the center frequency wavelength.

[0007] According to a preferred embodiment, the matching circuit includes a radio frequency power resistor R1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first inductor L1 and a second inductor L2;

[0008] Among them, the first end of the RF power resistor R1 is connected to the first end of the feed plate, the second end of the RF power resistor R1 is connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is respectively connected to the first end of the second capacitor C2 and the first end of the first inductor L1, the second end of the second capacitor C2 is grounded, the second end of the first inductor L1 is respectively connected to the first end of the third capacitor C3 and the first end of the second inductor L2, the second end of the third capacitor C3 is grounded, the second end of the second inductor L2 is connected to the first end of the fourth capacitor C4, and the second end of the fourth capacitor C4 is connected to the RF connector.

[0009] According to a preferred embodiment, the first inductor L1 and the second inductor L2 are wire-wound air-core inductors;

[0010] The inner diameter of the first inductor is set between [1.8 mm, 2.1 mm], and the number of turns is set between [7, 8]. The inner diameter of the second inductor is set between [1.8 mm, 2 mm], and the number of turns is set between [22, 24].

[0011] According to a preferred implementation, the resistance of the RF power resistor R1 is 10 ohms.

[0012] According to a preferred embodiment, the capacitance of the first capacitor C1 is set between [60pF, 70pF], the capacitance of the second capacitor C2 is set between [25pF, 35pF], the capacitance of the third capacitor C3 is set between [15pF, 25pF], and the capacitance of the fourth capacitor C3 is set between [5pF, 15pF].

[0013] According to a preferred embodiment, when the working frequency band of the antenna is 118 MHz to 137 MHz, the capacitance of the first capacitor C1 is set to 68 pF, the capacitance of the second capacitor C2 is set to 27 pF, the capacitance of the third capacitor C3 is set to 22 pF, and the capacitance of the fourth capacitor C3 is set to 6.8 pF;

[0014] The diameter of the first inductor is 2 mm, and the number of turns is 7 turns; the inner diameter of the second inductor is 2 mm, and the number of turns is 23 turns.

[0015] According to a preferred embodiment, the radiation component further comprises a support member, a first end of the support member is fixed on the radiator, and a second end of the support member is fixed on a ground base, so that the radiator and the ground base form an inclination angle of 90°.

[0016] According to a preferred embodiment, it also includes an antenna cover, which is arranged on the lower part of the radiator, the matching circuit, the feeding plate and the support.

[0017] According to a preferred embodiment, the length of the radiator is 605±5 mm.

[0018] The technical solution of a low-height L-shaped airborne ultra-short wave antenna in an embodiment of the utility model has at least the following advantages and beneficial effects: the airborne ultra-short wave antenna bends the radiator into an L-shape so that the vertical height of the bent lower part of the radiator is less than 1 / 15 of the wavelength of the center frequency, so as to meet the requirements of the aircraft for a low-height monopole antenna, and by loading a matching circuit, the antenna can be better matched within a predetermined frequency band and ensure a reasonable gain. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A top view of the airborne ultra-short wave antenna provided in Example 1 of the utility model;

[0020] Figure 2 A bottom view of the airborne ultrashort wave antenna provided in Example 1 of the utility model;

[0021] Figure 3 This is a view of the airborne ultra-short wave antenna provided in Example 1 of the utility model, with the left side viewing angle rotated 90° to the left;

[0022] Figure 4 A front view of the airborne ultra-short wave antenna provided in Example 1 of the utility model;

[0023] Figure 5 A cross-sectional view of the airborne ultra-short wave antenna provided in Example 1 of the utility model, with the left side viewing angle rotated 90° to the left;

[0024] Figure 6A cross-sectional view of the airborne ultra-short wave antenna provided in Example 1 of the utility model from the front perspective;

[0025] Figure 7 A schematic diagram of a matching circuit provided in Example 1 of the utility model;

[0026] Figure 8 A typical horizontal radiation pattern of the antenna provided in Example 1 of the utility model in the frequency range of 108MHz to 137MHz;

[0027] Icon: 100-RF connector, 200-antenna cover, 300-ground base, 400-radiation component, 410-radiator, 420-matching circuit, 430-feeding plate, 440-support, 450-feeding point, 500-rivet sleeve. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] Example 1

[0030] See also Figures 1 to 4 As shown, this embodiment provides a low-height L-shaped airborne ultra-short wave antenna, including a radio frequency connector 100, a ground base 300 and a radiation component 400, wherein the radio frequency connector 100 is fixedly connected to the bottom surface of the ground base 300 by screws, and the radiation component 400 is fixedly connected to the top surface of the ground base 300 by screws.

[0031] Specifically, the radiation component 400 is composed of a radiator 410, a matching circuit 420 and a feeding plate 430. The matching circuit 420 is arranged on the top surface of the ground base 300 and is fixedly connected to the top surface of the ground base 300 by screws. The output end of the matching circuit 420 is electrically connected to the RF connector 100, and the input end of the matching circuit 420 is electrically connected to the first end of the feeding plate 430. The second end of the feeding plate 430 is fixedly connected to the radiator 410. The connection point between the feeding plate 430 and the radiator 410 serves as a feeding point 450. The feeding point 450 is located at the bottom of the radiator 410. The radiator 410 is electrically connected to the input end of the matching circuit 420 through the feeding plate 430.

[0032] Furthermore, the radiator 410 is bent 90° toward the leeward side, so as to meet the aerodynamic requirements of the aircraft for the monopole antenna. In one implementation of this embodiment, the bent lower portion of the radiator 410 forms a 90° inclination angle with the ground base 300, and the vertical height of the bent lower portion of the radiator 410 is less than 1 / 15 of the center frequency wavelength. Preferably, in this embodiment, the height of the entire antenna is 154 mm, wherein the parameters of the radiator 410 are as follows: the distance between the top of the bending point of the radiator 410 and the bottom of the radiator 410 is 144.5 mm, the inner radius of the bending point of the radiator 410 is 25 mm, and the length of the radiator 410 is 605±5 mm or 605±3 mm.

[0033] See also Figures 5 to 7 As shown, further, the radiation component 400 also includes a support member 440, a first end of the support member 440 is fixed on the radiator 410, and a second end of the support member 440 is fixed on the ground base 300, and the support member 440 is used to fix and support the radiator 410 so that the radiator 410 forms a 90° inclination angle with the ground base 300.

[0034] Furthermore, the antenna also includes an antenna cover 200. After the radiation component 400 is installed, the antenna cover 200 is placed on the lower part of the radiator 410, the matching circuit 420, the feed plate 430 and the support 440. The radiator 410 and the antenna cover 200 are bonded by an adhesive and then reinforced by a riveting sleeve 500 to ensure the stability of the connection between the radiator 410 and the ground base 300 and the antenna cover 200, which can effectively prevent the antenna from deforming under airflow disturbance or vibration during flight. In one implementation of this embodiment, the antenna cover 200 can be made of fiberglass or engineering plastics such as nylon; in addition, it is worth mentioning that during the processing, the antenna needs to be painted except for the bottom surface of the ground base 300.

[0035] See also Figure 7As shown, the matching circuit 420 includes an RF power resistor R1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first inductor L1 and a second inductor L2; wherein, the first end of the RF power resistor R1 is connected to the first end of the feeding plate 430, the second end of the RF power resistor R1 is connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is respectively connected to the first end of the second capacitor C2 and the first end of the first inductor L1, the second end of the second capacitor C2 is grounded, the second end of the first inductor L1 is respectively connected to the first end of the third capacitor C3 and the first end of the second inductor L2, the second end of the third capacitor C3 is grounded, the second end of the second inductor L2 is connected to the first end of the fourth capacitor C4, and the second end of the fourth capacitor C4 is connected to the RF connector 100.

[0036] In one implementation of this embodiment, the first inductor L1 and the second inductor L2 are wire-wound hollow inductors; the inner diameter of the first inductor is set between [1.8 mm, 2.1 mm], and the number of turns is between [7, 8]; the inner diameter of the second inductor is set between [1.8 mm, 2 mm], and the number of turns is set between [22, 24].

[0037] Taking a certain type of rotorcraft antenna as an example, the operating frequency involved is 118MHz~137MHz. At this operating frequency, the design parameters of each component of the antenna are as follows:

[0038] The diameter of the radiator 410 is 8mm; the inner diameter of the first inductor L1 is 2mm, the number of turns is 7 turns, and the wire diameter is 0.5mm; the inner diameter of the second inductor L2 is 2mm, the number of turns is 24 turns, which can effectively improve the Q value of the inductor and reduce the loss; the resistance value of the RF power resistor R1 is 10 ohms, so that the matching circuit takes into account the input standing wave and gain indicators of the antenna; the capacitance of the first capacitor C1 is set between [60pF, 70pF], and the capacitance of the second capacitor C2 is The capacitance is set between [25pF, 35pF], the capacitance of the third capacitor C3 is set between [15pF, 25pF], and the capacitance of the fourth capacitor C3 is set between [5pF, 15pF]; specifically, the capacitance of the first capacitor C1 is set to 68pF, the capacitance of the second capacitor C2 is set to 27pF, the capacitance of the third capacitor C3 is set to 22pF, and the capacitance of the fourth capacitor C3 is set to 6.8pF. In this embodiment, the capacitor adopts RF chip capacitors. Under the above parameters, see Figure 8 As shown, the antenna has a full-band input standing wave ratio of less than 2.8:1, is horizontally omnidirectional, has a full-band gain greater than -5.1dBi, and a non-circularity of the radiation pattern less than 1dB.

[0039] In summary, the technical solution of a low-height L-shaped airborne ultra-short wave antenna provided in this embodiment has at least the following advantages and beneficial effects: the airborne ultra-short wave antenna bends the radiator 410 into an L-shape, so that the vertical height of the bent lower part of the radiator 410 is less than 1 / 15 of the center frequency wavelength, so as to meet the requirements of the aircraft for a low-height monopole antenna, and by loading the matching circuit 420, the disadvantages of narrowing the working bandwidth and making matching difficult due to the lowering of the antenna height are overcome, so that the antenna can be better matched within the predetermined frequency band and ensure reasonable gain.

[0040] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-height L-shaped airborne ultra-short wave antenna, comprising a radio frequency connector (100), a ground base (300) and a radiation component (400), wherein the radio frequency connector (100) is fixedly connected to the bottom surface of the ground base (300), and the radiation component (400) is fixedly connected to the top surface of the ground base (300), characterized in that: The radiation component (400) is composed of a radiator (410), a matching circuit (420) and a feeding plate (430); the matching circuit (420) is arranged on the top surface of the ground base (300); the output end of the matching circuit (420) is electrically connected to the radio frequency connector (100); the input end of the matching circuit (420) is electrically connected to the first end of the feeding plate (430); the second end of the feeding plate (430) is fixedly connected to the radiator (410); the connection point between the feeding plate (430) and the radiator (410) serves as a feeding point (450); the radiator (410) is bent 90° toward the leeward side; the bent lower part of the radiator (410) forms a 90° inclination angle with the ground base (300); and the vertical height of the bent lower part of the radiator (410) is less than 1 / 15 of the wavelength of the center frequency.

2. The low-height L-shaped airborne ultra-short wave antenna according to claim 1, characterized in that: The matching circuit (420) comprises a radio frequency power resistor R1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first inductor L1 and a second inductor L2; The first end of the RF power resistor R1 is connected to the first end of the feed plate (430), the second end of the RF power resistor R1 is connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is respectively connected to the first end of the second capacitor C2 and the first end of the first inductor L1, the second end of the second capacitor C2 is grounded, the second end of the first inductor L1 is respectively connected to the first end of the third capacitor C3 and the first end of the second inductor L2, the second end of the third capacitor C3 is grounded, the second end of the second inductor L2 is connected to the first end of the fourth capacitor C4, and the second end of the fourth capacitor C4 is connected to the RF connector (100).

3. The low-height L-shaped airborne ultra-short wave antenna according to claim 2, characterized in that: The first inductor L1 and the second inductor L2 are wire-wound air-core inductors.

4. The low-height L-shaped airborne ultra-short wave antenna according to claim 2, characterized in that: The resistance of the RF power resistor R1 is 10 ohms.

5. The low-height L-shaped airborne ultra-short wave antenna according to claim 2, characterized in that: The capacitance of the first capacitor C1 is set between [60pF, 70pF], the capacitance of the second capacitor C2 is set between [25pF, 35pF], the capacitance of the third capacitor C3 is set between [15pF, 25pF], and the capacitance of the fourth capacitor C3 is set between [5pF, 15pF]; The inner diameter of the first inductor is set between [1.8 mm, 2.1 mm], and the number of turns is set between [7, 8]. The inner diameter of the second inductor is set between [1.8 mm, 2 mm], and the number of turns is set between [22, 24].

6. The low-height L-shaped airborne ultra-short wave antenna according to claim 5, characterized in that: When the working frequency band of the antenna is 118 MHz to 137 MHz, the capacitance of the first capacitor C1 is set to 68 pF, the capacitance of the second capacitor C2 is set to 27 pF, the capacitance of the third capacitor C3 is set to 22 pF, and the capacitance of the fourth capacitor C3 is set to 6.8 pF; The diameter of the first inductor is 2 mm, and the number of turns is 7 turns; the inner diameter of the second inductor is 2 mm, and the number of turns is 23 turns.

7. The low-height L-shaped airborne ultra-short wave antenna according to any one of claims 1 to 6, characterized in that: The radiation component (400) further comprises a support member (440), wherein a first end of the support member (440) is fixed on the radiator (410), and a second end of the support member (440) is fixed on the ground base (300), so that the radiator (410) and the ground base (300) form an inclination angle of 90°.

8. The low-height L-shaped airborne ultra-short wave antenna according to claim 7, characterized in that: It also includes an antenna cover (200), which is arranged on the lower part of the radiator (410), the matching circuit (420), the feeding plate (430) and the support member (440).

9. The low-height L-shaped airborne ultra-short wave antenna according to claim 7, characterized in that: The length of the radiator (410) is 605±5 mm.

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