Inverted-F four-arm helical antenna for P-band sounding receiver

Abstract

The utility model discloses an inverted-F four-arm helical antenna for a P-band sounding receiver. The inverted-F four-arm helical antenna comprises a bottom plate, four inverted-F oscillators and a feed network, the four inverted-F-shaped oscillators are respectively arranged at four side edges of the front surface of the bottom plate, each inverted-F-shaped oscillator is of a planar inverted-F-shaped structure, and an oscillator radiating surface of each inverted-F-shaped oscillator is parallel to the bottom plate; and the feed network is arranged on the bottom plate, and the feed network is connected with the inverted F-shaped oscillator. According to the four-arm spiral antenna, the planar inverted-F antenna is adopted to replace a monopole antenna to serve as the antenna arms of the four-arm spiral antenna, the working mode is changed into a normal mode, the height of the antenna is effectively reduced, meanwhile, the feed phases of the four antenna arms are sequentially lagged by 90 degrees anticlockwise, right-hand circular polarization is formed, and polarization loss is effectively reduced.

Description

Technical Field

[0001] The present application relates to the technical field of high-altitude meteorological detection, and in particular to an inverted-F four-arm helical antenna for a P-band sounding receiver. Background Art

[0002] High-altitude meteorological detection based on P-band sondes uses sondes suspended from sounding balloons to observe high-altitude meteorological information. The sonde transmits the observation data to the receiving antenna on the ground through the transmitter, and the receiving antenna transmits it to the receiver for subsequent analysis and processing as the main basis for weather forecasting. The sonde is limited by cost, size and power supply. The general transmission power of the sonde is only 100mW. The transmitting antenna generally uses a simple quarter-wavelength monopole antenna with a gain of about 3dBi. The communication distance is generally required to be greater than 200kM, the free space loss is about 130dB, and the receiver sensitivity is generally -120dBm. Due to the linear polarization characteristics of the monopole transmitting antenna and the polarization loss caused by the uncertainty of the direction of the transmitting antenna swaying in the air, specific requirements are put forward for the gain, lobe width and polarization characteristics of the receiver antenna. Some receivers use six Yagi antennas and one The combination of flat antennas and switch switching is used to widen the lobe width to achieve full coverage of 360 degrees in azimuth and 90 degrees in elevation. However, this method has the disadvantages of high cost, switch delay, and high polarization loss of the transmitting antenna when it swings horizontally due to the linear polarization of the Yagi antenna. Some receivers are improved to use axial-mode helical antennas to achieve circular polarization characteristics. This helical antenna uses four monopole antennas wrapped around each other as antenna arms to achieve circular polarization characteristics. However, since the length of the monopole antenna is one-quarter wavelength, the height of the receiving antenna exceeds 180 mm, which is not conducive to carrying. Summary of the invention

[0003] The present application provides an inverted-F four-arm helical antenna for a P-band sounding receiver. The advantage is that a planar inverted-F antenna is used instead of a monopole antenna as the antenna arm of the four-arm helical antenna, and the working mode is changed to a normal mode, which effectively reduces the height of the antenna. At the same time, the feeding phase of the four antenna arms is delayed by 90 degrees counterclockwise to form right-hand circular polarization, which effectively reduces the polarization loss.

[0004] The above-mentioned object of the present application is achieved through the following technical scheme: an inverted F quadrifilar helical antenna for a P-band sounding receiver, comprising:

[0005] Base plate;

[0006] Four inverted F-type vibrators, the four inverted F-type vibrators are respectively arranged at four side positions of the front side of the bottom plate, the inverted F-type vibrator is a plane inverted F structure, and the vibrator radiation surface of the inverted F-type vibrator is parallel to the bottom plate;

[0007] And a feeding network, wherein the feeding network is arranged on the bottom plate and connected to the inverted-F type oscillator.

[0008] According to the above scheme, two opposite inverted F-type vibrators are parallel to each other, and two adjacent inverted F-type vibrators are perpendicular to each other.

[0009] According to the above scheme, the inverted F-type vibrator is formed by bending a copper plate into four rectangular surfaces: the vibrator radiation surface, the vibrator grounding surface, the vibrator feeding surface and the vibrator tuning surface. The vibrator grounding surface is the short-circuit end of the inverted F-type vibrator, and the vibrator feeding surface is the feeding end of the inverted F-type vibrator pair.

[0010] According to the above scheme, the four inverted F-type oscillators are fed with equal amplitude, and the phase lags by 90 degrees in a counterclockwise direction to form right-hand circular polarization.

[0011] According to the above scheme, the feeding network includes a circuit board and three Wilkinson power dividers. The power divider is implemented on the circuit board using a coplanar waveguide structure. The feed input is distributed by the three Wilkinson power dividers to feed four inverted F-type oscillators.

[0012] The output arm on one side of the Wilkinson power divider is one quarter wavelength longer than the output arm on the other side, so that the feeding ends of adjacent inverted F-type oscillators differ by 90 degrees, forming a right-hand circularly polarized antenna.

[0013] According to the above solution, the bottom plate is an aluminum plate, which is in conductive contact with the back side of the circuit board in the feed network.

[0014] According to the above scheme, the working frequency of the antenna is 400 MHz to 406 MHz.

[0015] In summary, the beneficial effects of this application are:

[0016] 1. This application uses a planar inverted F antenna instead of a monopole antenna as the antenna arm of the quadrifilar helical antenna, changes the working mode to a normal mode, effectively reduces the height of the antenna, and at the same time, lags the feeding phase of the four antenna arms by 90 degrees counterclockwise to form right-hand circular polarization, effectively reducing polarization loss;

[0017] 2. This application not only fully meets the distance and omnidirectionality requirements of high-altitude meteorological detection, but also has the characteristics of low cost, small size and easy portability;

[0018] 3. The present invention has the advantages of miniaturization, low profile, easy to carry, low axial ratio, high gain and wide beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is an overall diagram of an inverted-F quadrifilar helical antenna for a P-band sounding receiver in a specific embodiment of the present application.

[0020] Figure 2 This is a dipole diagram of an inverted-F quadrifilar helical antenna for a P-band sounding receiver in a specific embodiment of the present application.

[0021] Figure 3 This is a feeding network diagram of an inverted-F quadrifilar helical antenna for a P-band sounding receiver in a specific embodiment of the present application.

[0022] Figure 4 This is a back panel diagram of an inverted-F quadrifilar helical antenna for a P-band sounding receiver in a specific embodiment of the present application.

[0023] Figure 5 This is a 2D gain diagram of an inverted-F quadrifilar helical antenna used in a P-band sounding receiver in a specific embodiment of the present application.

[0024] Figure 6 This is an axial ratio diagram of an inverted-F quadrifilar helical antenna for a P-band sounding receiver in a specific embodiment of the present application.

[0025] Figure 7 This is a parameter diagram of the input end S11 of an inverted-F quadrifilar helical antenna used in a P-band sounding receiver in a specific embodiment of the present application.

[0026] In the figure, 1 is an inverted F-type oscillator, 2 is a feeding network, 3 is a bottom plate, 4 is a radiating surface of the oscillator, 5 is a grounding surface of the oscillator, 6 is a feeding surface of the oscillator, 7 is a tuning surface of the oscillator, 8 is a feeding end of the oscillator, 9 is a Wilkinson power divider, 10 is a Wilkinson power divider, 11 is a feeding end of the oscillator, 12 is a feeding end of the oscillator, 13 is a Wilkinson power divider, and 14 is a feeding end of the oscillator. Implementation

[0027] The specific implementation of the present application is described in detail below with reference to the accompanying drawings.

[0028] Embodiment: An inverted F quadrifilar helical antenna for a P-band sounding receiver, referring to Figure 1 , including a base plate, four inverted F-type oscillators and a feeding network.

[0029] refer to Figure 1 and 2 , four inverted F-type vibrators are respectively arranged at the four side positions of the front side of the bottom plate, two opposite inverted F-type vibrators are parallel to each other and the distance is 134mm, and two adjacent inverted F-type vibrators are perpendicular to each other. The inverted F-type vibrator is a planar inverted F structure, and the vibrator radiation surface of the inverted F-type vibrator is parallel to the bottom plate; the inverted F-type vibrator is bent by a copper plate into four rectangular surfaces: the vibrator radiation surface, the vibrator grounding surface, the vibrator feeding surface and the vibrator tuning surface, the vibrator grounding surface is the short-circuit end of the inverted F-type vibrator, and the vibrator feeding surface is the feeding end of the inverted F-type vibrator pair.

[0030] Specifically, in this embodiment, the inverted F-type vibrator is formed into four rectangles by bending a copper plate with a thickness of 0.5 mm, wherein the vibrator radiation surface 4 has a size of 154 mm*43 mm, the vibrator grounding surface 5 has a size of 34 mm*24 mm, the vibrator tuning surface 7 has a size of 154 mm*8 mm, and the vibrator feeding surface 6 has a size of 16 mm*9 mm.

[0031] refer to Figure 1 and 3 The feeding network is arranged on the bottom plate, and the feeding network is connected to the inverted F-type oscillator. The four inverted F-type oscillators are fed with equal amplitude, and the phases are sequentially delayed by 90 degrees in a counterclockwise direction to form right-hand circular polarization.

[0032] Due to the limitation of the size of the whole device, the four arms of the helical antenna are close to each other, and the distance between two arms is about one-fifth of the wavelength, which causes strong coupling between the four arms of the antenna. Therefore, when matching the feeding ports of the four arms, we cannot use the traditional method of matching each port individually and then adding a power division network. Instead, we should fully consider the coupling between the four arms.

[0033] Specifically, the feeding network includes a circuit board and three Wilkinson power dividers. The feed input is distributed by the three Wilkinson power dividers to feed four inverted F-type oscillators. The power divider is implemented on the circuit board using a coplanar waveguide structure. The board thickness is 1 mm and the relative dielectric constant is 2.94. The output arm on one side of the Wilkinson power divider is one-quarter wavelength longer than the output arm on the other side, so that the feeding ends of adjacent inverted F-type oscillators differ by 90 degrees, forming a right-handed circularly polarized antenna. Specifically, the right output arm of the Wilkinson power divider is one-quarter wavelength longer than the left output arm, which ultimately makes the feeding end 11 of the four inverted F-type oscillators lag 90 degrees behind the feeding end 12, the feeding end 12 lags 90 degrees behind the feeding end 14, and the feeding end 14 lags 90 degrees behind the feeding end 8.

[0034] refer to Figure 4 The bottom plate is an aluminum plate with a thickness of 0.5 mm and a size of 286 mm*286 mm. The bottom plate is in conductive contact with the back of the circuit board in the feed network.

[0035] refer to Figure 5 After simulation, it is found that the antenna gain is 4.5dBi at most and -2.7dBi at least in the range of 0 to 360 degrees in azimuth and 0 to 90 degrees in elevation, and the 3dB beam width is greater than 120 degrees, which meets the link gain requirements between the receiver and the sounding instrument.

[0036] refer to Figure 6 ,After simulation, the antenna axial ratio is less than 2.5dB in the 400MHz to 406MHz frequency band, which meets the polarization loss ,requirements of circularly polarized antenna. Figure 6 In the figure, the horizontal axis is the frequency and the vertical axis is the axis ratio.

[0037] refer to Figure 7 ,After simulation, it is found that the S11 parameter of the antenna input is less than -20dB in the frequency band of 400MHz to 406MHz, which meets the receiver's requirement for the input standing wave ratio. Figure 7 In the figure, the horizontal axis is the frequency and the vertical axis is the input terminal S11 value.

[0038] The function of the inverted-F four-arm helical antenna for the P-band sounding receiver mentioned in this embodiment is to receive the radio frequency signal sent back by the P-band sounding at high altitude and transmit it to the receiver.

[0039] The technical parameters of the inverted F quadrifilar helical antenna for the P-band sounding receiver in this embodiment are as follows:

[0040] Working frequency band: 400Mhz-406MHz.

[0041] The input S11 parameter is less than -20dB.

[0042] Maximum gain 4.5dBi.

[0043] Minimum gain -2.7dBi.

[0044] The axial ratio is less than 2.5dB.

[0045] The 3dB beamwidth is greater than 120 degrees.

[0046] The parts not involved in the present invention are the same as the prior art or are implemented by using the prior art.

[0047] The above is only a preferred implementation of the present application. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present application, and these all fall within the scope of protection of the present application.

Claims

1. An inverted F quadrifilar helical antenna for a P-band sounding receiver, characterized in that: include: Base plate; Four inverted F-type vibrators, the four inverted F-type vibrators are respectively arranged at four side positions of the front side of the bottom plate, the inverted F-type vibrator is a plane inverted F structure, and the vibrator radiation surface of the inverted F-type vibrator is parallel to the bottom plate; And a feeding network, wherein the feeding network is arranged on the bottom plate and connected to the inverted-F type oscillator.

2. The inverted F quadrifilar helical antenna for a P-band sounding receiver according to claim 1, characterized in that: The two opposite inverted F-type vibrators are parallel to each other, and the two adjacent inverted F-type vibrators are perpendicular to each other.

3. The inverted-F quadrifilar helical antenna for a P-band sounding receiver according to claim 2, characterized in that: The inverted F-type vibrator is formed by bending a copper plate into four rectangular surfaces: a vibrator radiation surface, a vibrator grounding surface, a vibrator feeding surface and a vibrator tuning surface. The vibrator grounding surface is the short-circuit end of the inverted F-type vibrator, and the vibrator feeding surface is the feeding end of the inverted F-type vibrator pair.

4. The inverted-F quadrifilar helical antenna for a P-band sounding receiver according to any one of claims 1 to 3, characterized in that: The four inverted F-type oscillators are fed with equal amplitude, and the phase lags by 90 degrees in a counterclockwise direction to form right-hand circular polarization.

5. The inverted-F quadrifilar helical antenna for a P-band sounding receiver according to claim 4, characterized in that: The feeding network includes a circuit board and three Wilkinson power dividers. The power divider is implemented on the circuit board using a coplanar waveguide structure. The feed input is distributed by the three Wilkinson power dividers to feed four inverted F-type oscillators. The output arm on one side of the Wilkinson power divider is one quarter wavelength longer than the output arm on the other side, so that the feeding ends of adjacent inverted F-type oscillators differ by 90 degrees, forming a right-hand circularly polarized antenna.

6. The inverted-F quadrifilar helical antenna for a P-band sounding receiver according to claim 5, characterized in that: The bottom plate is an aluminum plate and is in conductive contact with the back side of the circuit board in the feed network.

7. The inverted-F quadrifilar helical antenna for a P-band sounding receiver according to claim 1, characterized in that: The antenna operates at a frequency of 400 MHz to 406 MHz.

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