阅读说明：本技术 飞行器、定位天线设备及用于定位天线的电路装置 (Aircraft, positioning antenna device and circuit arrangement for positioning antenna ) 是由 许鹏鹏 张晋华 于 2021-08-23 设计创作，主要内容包括：本申请公开了一种飞行器、定位天线设备和用于定位天线的电路装置,其中利用功分器将来自飞行器定位天线的定位信号分别输出给定位天线的飞行器天线接收机和雷达天线接收机,以便飞行器天线接收机基于定位信号确定飞行器的位置,雷达天线接收机基于定位信号确定机载雷达的位置。根据本发明实施例,定位天线接收的定位信号能够被同时用于确定飞行器的位置和机载雷达的位置,消除了对专用于机载雷达的定位天线的需求；与此同时,设置在第一功分器与雷达天线接收机之间的防倒灌电容器能够隔断直流,从而保护机载雷达免受定位天线的馈电电流的影响。(The application discloses aircraft, location antenna equipment and be used for circuit arrangement of location antenna, wherein utilize the merit to divide the locating signal that comes from aircraft location antenna to export respectively to aircraft antenna receiver and the radar antenna receiver of location antenna for aircraft antenna receiver is based on the locating signal location of aircraft, and radar antenna receiver is based on the locating signal location of airborne radar of location determination. According to the embodiment of the invention, the positioning signals received by the positioning antenna can be simultaneously used for determining the position of the aircraft and the position of the airborne radar, so that the requirement on the positioning antenna special for the airborne radar is eliminated; meanwhile, the backflow prevention capacitor arranged between the first power divider and the radar antenna receiver can cut off direct current, so that the airborne radar is protected from being influenced by feed current of the positioning antenna.)

1. An aircraft on which an onboard radar can be carried, the aircraft comprising:

a positioning antenna for receiving a positioning signal;

an aircraft antenna receiver that receives and processes the positioning signals for determining a position of the aircraft; and

a radar antenna receiver for determining a position of the airborne radar,

wherein the aircraft further comprises a first power divider through which a positioning signal from the positioning antenna is output to the aircraft antenna receiver and the radar antenna receiver, the radar antenna receiver determining a position of the airborne radar based on the positioning signal; and is

The aircraft antenna receiver feeds power to the positioning antenna, and the aircraft further comprises a backflow prevention capacitor connected between the first power divider and the radar antenna receiver and used for cutting off direct current.

2. The aircraft of claim 1, further comprising an anti-glitch shorting resistor connected between the first power divider and the aircraft antenna receiver, the anti-glitch shorting resistor having a resistance value to suppress transient currents in the circuit below a current threshold that can trigger short circuit protection.

3. A circuit device for an aircraft positioning antenna comprises a first power divider and a backflow prevention capacitor, wherein the first power divider is used for being connected to the positioning antenna and outputting a positioning signal from the positioning antenna to a first output circuit and a second output circuit, and the backflow prevention capacitor is arranged in the first output circuit and used for cutting off direct current.

4. A circuit arrangement as claimed in claim 3, wherein the anti-back-flow capacitor has a capacitance of 56pF or more, preferably 100pF or more.

5. The circuit arrangement of claim 3, further comprising a glitch-preventing shorting resistor disposed in the second output circuit and having a resistance value to suppress instantaneous current in the circuit below a current threshold capable of triggering short circuit protection.

6. The circuit arrangement of any of claims 3-5, further comprising a filter circuit in series with the first power divider, the filter circuit capable of turning on DC and attenuating signals in a first frequency band, the first frequency band being adjacent to an operating frequency band of the positioning antenna.

7. The circuit arrangement of claim 6, wherein the filtering circuit comprises a second power divider, a third power divider, and a first band-pass filter, a second band-pass filter and a traffic-blocking inductor connected in parallel between the second power divider and the third power divider, the first band-pass filter is configured to pass signals of a second frequency band, the second band-pass filter is configured to pass signals of a third frequency band, and the first frequency band is located between the second frequency band and the third frequency band.

8. The circuit arrangement of claim 6, further comprising a traffic-blocking direct inductor in parallel with the filter circuit.

9. The circuit arrangement of claim 7, wherein the filtering circuit further comprises:

a first limiter connected in series with the first band pass filter between the second power divider and the third power divider; and

a second limiter connected in series with the second band pass filter between the second power divider and the third power divider.

10. A positioning antenna device comprising a positioning antenna and a circuit arrangement according to any of claims 3-9 connected to the positioning antenna.

11. The positioning antenna device of claim 10, wherein the positioning antenna is an RTK antenna.

12. An aircraft on which an onboard radar can be carried, the aircraft comprising:

a positioning antenna for receiving a positioning signal;

an aircraft antenna receiver that receives and processes the positioning signals for determining a position of the aircraft; and

a radar antenna receiver for determining a position of the airborne radar,

wherein the aircraft antenna receiver feeds the positioning antenna, and the aircraft further comprises a circuit arrangement according to any one of claims 3-9, which circuit arrangement is connected between the positioning antenna and the radar antenna receiver and the aircraft antenna receiver, so that a positioning signal from the positioning antenna is output by the first output circuit to the radar antenna receiver and by the second output circuit to the aircraft antenna receiver via the circuit arrangement, the radar antenna receiver determining the position of the airborne radar on the basis of the positioning signal.

Technical Field

The present invention relates to antenna positioning technology for aircraft, and in particular to a circuit arrangement for an aircraft positioning antenna, a positioning antenna device comprising such a circuit arrangement, and an aircraft.

Background

In an aircraft (e.g., an unmanned aerial vehicle) equipped with a radar, a positioning antenna (e.g., an RTK antenna, a GPS antenna, etc.) is generally provided separately for the aircraft and the radar. In order to meet the detection requirement, the radar is generally arranged on the belly of the aircraft, the radar positioning antenna is generally arranged on the upper portion of the radar, and therefore the radar positioning antenna cannot receive signals due to shielding of a cabin cover or other body structures.

Disclosure of Invention

It is an object of the present invention to provide a circuit arrangement for an aircraft positioning antenna, a positioning antenna device and an aircraft comprising such a circuit arrangement, which overcome the problems of the prior art.

According to an aspect of the present invention, there is provided an aircraft on which an onboard radar can be mounted, the aircraft comprising: a positioning antenna for receiving a positioning signal; an aircraft antenna receiver that receives and processes the positioning signals for determining a position of the aircraft; and a radar antenna receiver for determining the position of the airborne radar. The aircraft further comprises a first power divider, a positioning signal from the positioning antenna is output to the aircraft antenna receiver and the radar antenna receiver through the first power divider, and the radar antenna receiver determines the position of the airborne radar based on the positioning signal; and the aircraft antenna receiver feeds the positioning antenna, and the aircraft further comprises a backflow prevention capacitor connected between the first power divider and the radar antenna receiver and used for cutting off direct current.

Preferably, the aircraft may further comprise a glitch-preventing short-circuit resistor connected between the first power divider and the aircraft antenna receiver, the glitch-preventing short-circuit resistor having a value to suppress instantaneous current in the circuit to a level below a current threshold capable of triggering short-circuit protection.

According to another aspect of the present invention, a circuit device for an aircraft positioning antenna is provided, which includes a first power divider and a backflow prevention capacitor, wherein the first power divider is configured to be connected to the positioning antenna and output a positioning signal from the positioning antenna to a first output circuit and a second output circuit, and the backflow prevention capacitor is disposed in the first output circuit and configured to block a direct current.

Advantageously, the anti-backflow capacitor has a capacitance value of 56pF or greater, preferably 100pF or greater.

Preferably, the circuit arrangement may further comprise a glitch-preventing short-circuit resistor provided in the second output circuit and having a resistance value to suppress a momentary current in the circuit to a level below a current threshold capable of triggering short-circuit protection.

Preferably, the circuit arrangement may further include a filter circuit connected in series with the first power divider, the filter circuit being capable of turning on a direct current and attenuating signals in a first frequency band, the first frequency band being adjacent to an operating frequency band of the positioning antenna.

Advantageously, the filter circuit may include a second power divider, a third power divider, and a first band pass filter, a second band pass filter and a traffic isolating straight inductor connected in parallel between the second power divider and the third power divider, the first band pass filter being configured to pass signals of a second frequency band, the second band pass filter being configured to pass signals of a third frequency band, and the first frequency band being located between the second frequency band and the third frequency band.

Preferably, the circuit arrangement may further comprise a traffic-cut direct inductor, which is connected in parallel with the filter circuit.

Preferably, the filter circuit may further include: a first limiter connected in series with the first band pass filter between the second power divider and the third power divider; and a second limiter connected in series with the second band pass filter between the second power divider and the third power divider.

According to a further aspect of the present invention, there is provided a positioning antenna device comprising a positioning antenna and a circuit arrangement as described above connected to the positioning antenna.

In some embodiments, the positioning antenna is an RTK antenna.

According to still another aspect of the present invention, there is provided an aircraft on which an onboard radar can be mounted, the aircraft including: a positioning antenna for receiving a positioning signal; an aircraft antenna receiver that receives and processes the positioning signals for determining a position of the aircraft; and a radar antenna receiver for determining the position of the airborne radar. The aircraft antenna receiver feeds the positioning antenna, and the aircraft further comprises a circuit arrangement as described above, which circuit arrangement is connected between the positioning antenna and the radar antenna receiver and the aircraft antenna receiver, so that a positioning signal from the positioning antenna is output by the first output circuit to the radar antenna receiver via the circuit arrangement and by the second output circuit to the aircraft antenna receiver, which radar antenna receiver determines the position of the airborne radar on the basis of the positioning signal.

According to the embodiment of the invention, the positioning signals received by the positioning antenna can be simultaneously used for determining the position of the aircraft and the position of the airborne radar, so that the requirement on the positioning antenna special for the airborne radar is eliminated; meanwhile, the backflow prevention capacitor arranged between the first power divider and the radar antenna receiver can cut off direct current, so that the airborne radar is protected from being influenced by feed current of the positioning antenna.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic structural diagram of an aircraft according to an embodiment of the invention;

FIG. 2 is a schematic block diagram of an aircraft using a circuit arrangement for locating an antenna according to a first embodiment of the invention, according to another embodiment of the invention;

fig. 3 is a schematic block diagram of a circuit arrangement for an aircraft positioning antenna according to a second embodiment of the invention;

fig. 4 is a schematic block diagram of a circuit arrangement for an aircraft positioning antenna according to a third embodiment of the invention;

FIG. 5 shows an example of a filter circuit that may be used in the circuit arrangement of FIG. 4, wherein the filter circuit is formed using an LC tank circuit; and

fig. 6 and 7 show two other examples of the circuit arrangement shown in fig. 4, respectively.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

Fig. 1 is a schematic structural view of an aircraft 1 according to an embodiment of the invention. As shown in fig. 1, an aircraft 1 can carry an airborne radar 2, the aircraft 1 comprising a positioning antenna 10 for receiving positioning signals, an aircraft antenna receiver 20 and a radar antenna receiver 30. The radar antenna receiver 30 in the present embodiment is integrated within the on-board radar 2. According to an embodiment of the present invention, the aircraft 1 further includes a power divider (first power divider) 40, and the power divider 40 is configured such that the positioning signal from the positioning antenna 10 is output to the aircraft antenna receiver 20 and the radar antenna receiver 30 through the power divider 40. The aircraft antenna receiver 20 receives and processes the positioning signals to determine the position of the aircraft 1. The radar antenna receiver 30 determines the position of the airborne radar 2 based on the positioning signals.

According to the embodiment of the present invention, since the positioning signal of the positioning antenna 10 is output to the aircraft antenna receiver 20 and the radar antenna receiver 30 through the power divider 40, the need for a positioning antenna dedicated to the airborne radar 2 is eliminated. Therefore, the number of positioning antennas required to be configured on the aircraft is reduced, the structure is simplified, and the cost is reduced.

In addition, the inventor finds that: in the prior art, if a radar positioning antenna is independently arranged on a radar, a hole needs to be formed for finding the position of the radar positioning antenna. In practice, the positioning antenna of the aircraft requires a high-precision position, and the positioning antenna of the radar also requires a high-precision position. In practical situations, the electromagnetic interference on the aircraft is very much, and it is almost impossible to find two positions with less electromagnetic interference on one aircraft at the same time, or even only one position with relatively less interference can be found. Therefore, the common positioning antenna 10 is placed at the position, and the power divider 40 shares the positioning antenna 10, so that the antenna position accuracy of the aircraft and the radar is optimal, the aircraft carrying the radar can still fly stably, and an unexpected good effect is achieved.

It should be understood that the positions of the airborne radar 2, the positioning antenna 10, the aircraft antenna receiver 20, the radar antenna receiver 30 and the power divider 40 in the aircraft 1 shown in fig. 1 are merely illustrative and not limiting. For example, in the example shown in fig. 1, the aircraft 1 is, for example, a drone, the airborne radar 2 is mounted in a pod of the drone, and the radar antenna receiver 30 is integrated in the airborne radar 2, however the invention is not limited to a specific arrangement position of the airborne radar 2 and the radar antenna receiver 30. As another example, the positioning antenna 10, where the received positioning signals are shared by the power splitter 40 to the aircraft antenna receiver 20 and the radar antenna receiver 30, may be any one of a set of positioning antennas (e.g., RTK antennas or other types of antennas) for determining the position and orientation of the aircraft 1. Preferably, as shown in fig. 1, the positioning antenna 10 may be a front directional antenna in a set of RTK antennas, and the higher positioning measurement accuracy of the front directional antenna is favorable for obtaining a more accurate position of the airborne radar 2. The front positioning antenna is usually used as a main antenna, and when the interference is small, the positioning measurement precision is high. Furthermore, power splitter 40, although shown as a separate device in fig. 1, in other examples, power splitter 40 may form a positioning antenna device with positioning antenna 10, or be assembled or integrated with aircraft antenna receiver 20 to form an integrated aircraft antenna receiver, for example, although the invention is not limited in this respect.

Fig. 2 schematically shows an aircraft 1' according to a further embodiment of the invention by means of a block diagram. As shown in fig. 2, an onboard radar 2 'may be carried in an aircraft 1' and includes a positioning antenna 10, an aircraft antenna receiver 20, a radar antenna receiver 30, and a circuit arrangement 100 for a positioning antenna according to an embodiment of the present invention. The circuit arrangement 100 is connected between the positioning antenna 10 and the aircraft antenna receiver 20 and the radar antenna receiver 30 and comprises a power divider 110, which power divider 110 corresponds to the power divider 40 shown in fig. 1 and is configured to be connected to the positioning antenna 10 and to output a positioning signal from the positioning antenna 10 to a first output circuit a and a second output circuit b. The positioning signal can be output by the circuit arrangement 100 from the first output circuit a to the radar antenna receiver 30 and from the second output circuit b to the aircraft antenna receiver 20. Similar to the aircraft 1 shown in fig. 1, the aircraft antenna receiver 20 in the aircraft 1 'receives and processes the positioning signals to determine the position of the aircraft 1, and the radar antenna receiver 30 determines the position of the airborne radar 2' based on the positioning signals.

The difference from the embodiment shown in fig. 1 is that, in the embodiment shown in fig. 2, the circuit apparatus 100 further includes a backflow prevention capacitor 120 in addition to the power divider 110, and the backflow prevention capacitor 120 is disposed in the first output circuit a. In this way, when the circuit arrangement 100 is incorporated in the aircraft 1', the backflow prevention capacitor 120 is connected between the power divider 110 and the radar antenna receiver 30, and the dc current between the power divider 110 and the radar antenna receiver 30 can be blocked by the blocking characteristic of the capacitor.

This arrangement is so configured because the inventors of the present invention found that: it would be advantageous if the positioning antenna 10 could be fed by the aircraft antenna receiver 20. However, in the circuit apparatus 100 according to the embodiment of the present invention, the two output circuits of the power divider 110, the first output circuit a and the second output circuit b, are not completely independent and isolated, so that the dc feed current provided by the aircraft antenna receiver 20 to the positioning antenna 10 may flow backward to the radar antenna receiver 30 via the power divider 110, causing impact and damage to the radar antenna receiver 30. Vice versa, if a feed power supply is provided in the radar antenna receiver 30, the feed current from the radar antenna receiver 30 may also flow backward to the aircraft antenna receiver 20 via the power divider 110, causing impact and damage to the aircraft antenna receiver 20. Specifically, the dc feed current flows backward to the radar antenna receiver 30 via the power divider 110, or the feed current flows backward to the aircraft antenna receiver 20 via the power divider 110, depending on the voltage levels of the aircraft antenna receiver 20 and the radar antenna receiver 30. If the voltage of the aircraft antenna receiver 20 is higher than the voltage of the radar antenna receiver 30, the reverse flow is directed to the radar antenna receiver 30; if the voltage of the radar antenna receiver 30 is higher than the voltage of the aircraft antenna receiver 20, the reverse flow is to the aircraft antenna receiver 20.

In view of this problem, the inventors propose to provide a back-flow prevention capacitor 120 in the first output circuit a connected to the airborne radar 30 to block direct current and prevent the direct current from flowing back to the airborne radar 30. Since the aircraft antenna receiver 20 of the aircraft usually needs to know the working state of the positioning antenna 10, and this working state is usually realized by detecting a direct current, the arrangement of the anti-backflow capacitor 120 on the first output circuit a not only ensures that the aircraft antenna receiver 20 of the aircraft can normally detect the working state of the positioning antenna 10, but also can protect the radar antenna receiver 30 and the aircraft antenna receiver 20.

Advantageously, the capacitance of the anti-back-flow capacitor 120 is selected to be greater than or equal to 56pF, so that the blocking capacitance is selected to be much greater than the matching capacitance in the rf circuit, and the series connection does not affect the matching of the rf path. Preferably, the capacitance of the anti-backflow capacitor 120 is greater than or equal to 100 pF.

The power divider 110 is preferably a wilkinson power divider so as not to block the feeding dc current.

By way of example only, in the example shown in fig. 2, the radar antenna receiver 30 is not integrated in the on-board radar 2'. It should be understood that the radar antenna receiver may or may not be integrated in an onboard radar, in accordance with various embodiments of the present invention. When the radar antenna receiver is separated from the radar, the radar antenna receiver needs to be arranged between the power divider/anti-backflow capacitor and the airborne radar.

Only one embodiment of a circuit arrangement that can be incorporated in an aircraft according to an embodiment of the invention is shown in fig. 2. Next, a circuit arrangement 200 for an aircraft positioning antenna according to a second embodiment of the invention, which can be incorporated into an aircraft similarly to the circuit arrangement 100 shown in fig. 2, will be described with reference to fig. 3.

Similar to the circuit arrangement 100 shown in fig. 2, the circuit arrangement 200 shown in fig. 3 includes a power divider 210 and an optional anti-backflow capacitor 220, wherein the power divider 210 is configured to be connected to the positioning antenna 10 shown in fig. 1 and 2 and output a positioning signal from the positioning antenna 10 to a first output circuit a and a second output circuit b, so that the positioning signal can be output from the first output circuit a to the radar antenna receiver 30 and from the second output circuit b to the aircraft antenna receiver 20 through the circuit arrangement 200; the backflow prevention capacitor 220 is disposed in the first output circuit a, and may be configured to block a direct current between the power divider 210 and the radar antenna receiver 30.

A short-circuit protection circuit is typically provided in the receive path of the antenna to trigger short-circuit protection when the current is greater than some current threshold, e.g. 150 mA. The vibration of the aircraft, especially the vibration of the oil engine of the oil-fired aircraft, may often cause the instantaneous interruption of the connector in the circuit, produce the great instantaneous interruption current, cause the short-circuit protection circuit to send out the signal of the false alarm short circuit and cause the short-circuit protection to be triggered. According to the second embodiment of the present invention, as shown in fig. 3, the circuit apparatus 200 further includes an anti-glitch short-circuit resistor 230, which is disposed in the second output circuit b and has a certain resistance value to suppress the instantaneous current in the circuit to a level lower than a current threshold (e.g. 150mA) capable of triggering short-circuit protection. Therefore, the circuit instantaneous interruption can be prevented from being misinformed as a short circuit, unnecessary short circuit protection is restrained, and the positioning reliability of the aircraft is improved.

For the fixed wing unmanned aerial vehicle powered by fuel oil, the circuit R for preventing instantaneous interruption and false alarm is particularly favorable, wherein the resistance value of the resistor R for preventing instantaneous interruption and false alarm and short circuit can be selected to be 18-82 ohms, and the preferable ground resistance value can be 20-24 ohms.

Preferably, as shown in fig. 3, the circuit arrangement 200 may further include a first connector J1, a second connector J2, and a third connector J3, the first connector J1 being for connecting to the positioning antenna 10 (see fig. 2), the second connector J2 being for connecting to the aircraft antenna receiver 20 (see fig. 2), and the third connector J3 being for connecting to the radar antenna receiver 30 (see fig. 2).

The first connector J1, the second connector J2, and the third connector J3 are preferably SMA (Sub Miniature version a) connectors, particularly flanged SMA connectors. The thread connection mode of the SMA connector can effectively prevent circuit instantaneous interruption caused by bumping and vibration in the flying process of the aircraft, and ensure the flying positioning. The SMA connector, if provided with a flange, helps to prevent nearby, for example image transmission signals from coupling into the positioning antenna receiving circuit and blocking the aircraft antenna receiver 20.

Fig. 4 is a schematic block diagram of a circuit arrangement 300 for an aircraft positioning antenna according to a third embodiment of the invention. As shown in fig. 4, the circuit arrangement 300 includes a power divider 310 and an optional anti-backflow capacitor 320 disposed in a first output circuit a of the power divider 310, and the anti-backflow capacitor 320 may be used to block a direct current between the power divider 310 and the radar antenna receiver 30. The circuit device 300 may further include a glitch-preventing short-circuit resistor 330, and the glitch-preventing short-circuit resistor 330 may have the same structure and function as the glitch-preventing short-circuit resistor 230 in the circuit device 200 shown in fig. 3, and will not be described herein again.

Compared to the circuit apparatus 200 shown in fig. 3, the circuit apparatus 300 further includes a filter circuit 340 connected in series with the power divider 310. According to this embodiment, the filter circuit 340 is capable of conducting direct current and attenuating signals in a first frequency band adjacent to the operating frequency band of the positioning antenna 10. The filter circuit 340 in the circuit arrangement 300 is capable of conducting a direct current, so that the circuit arrangement 300 can simultaneously be used as part of the feed circuit of the positioning antenna 10.

As shown in fig. 4, the filter circuit 340 is preferably connected in series to the input side of the power divider 310.

The circuit arrangement 300 shown in fig. 4 is particularly advantageous for aircraft using RTK antennas as the positioning antenna 10. Specifically, the inventors of the present invention found that: a data link transmission module is typically provided on an aircraft, such as an unmanned aerial vehicle, and is typically located at a relatively close distance from the RTK antenna; the RTK antenna generally operates at two frequency bands with about 1.2G and 1.5G as center frequencies, while the legal frequency band generally used by the data chain transmission module in image transmission is generally about 1.4G, and in some cases, the legal frequency band is about 1.3G, which may cause signals for image data transmission to fall into the operating frequency band of the RTK antenna, and thus couple into an RTK path, and cause strong interference to RTK signal reception. In particular, the signal for image transmission requires a large power, and the transmission power thereof needs to be further increased in order to increase the image transmission distance, so that the signal for image data transmission may even saturate the RTK antenna receiver, causing receiver blockage, seriously affecting positioning and navigation. This is particularly dangerous for fixed wing aircraft. Heretofore, such risks have not been conscious and countermeasures have not been taken.

Advantageously, said first frequency band of the filter circuit 340 covers the data link frequency band used by a data link transmission module (not shown) on board the aircraft, so as to be able to attenuate the signals received by the RTK positioning antenna within the data link frequency band, thereby reducing the interference with the RTK positioning signal reception and processing.

Preferably, the first frequency band covers at least one of 1430-1438MHz frequency interval and 1438-1444MHz frequency interval. For example, in an advantageous embodiment, the first frequency band may cover the 1300-1450MHz frequency interval. 1430-1438MHz and 1438-1444MHz are two legal frequency intervals that can be used for image transmission, so at least one of the two frequency intervals is usually used by the data link frequency band of the data link transmission module 20. According to the embodiment of the present invention, at least one of the 1430-1438MHz frequency interval and the 1438-1444MHz frequency interval of the filter circuit 340 of the selection circuit device 300 covers may specifically reduce the interference of the image transmission signal of the data chain transmission module (not shown) to the RTK positioning signal receiving and processing, so as to reduce the risk that the RTK positioning system cannot normally operate.

Preferably, the circuit arrangement 300 may further comprise a first J1, a second J2 and a third J3 connector for connection to the positioning antenna 10, the aircraft antenna receiver 20 and the radar antenna receiver 30 (see fig. 2), respectively, and the first J1, the second J2 and the third J3 connector are preferably SMA connectors.

Fig. 5 shows an example of a filter circuit which can be used in the circuit arrangement shown in fig. 4, wherein the filter circuit is formed by an LC oscillating circuit. Specifically, in the example shown in fig. 5, the filter circuit 340 includes a first LC circuit LC1 and a second LC circuit LC 2. The first LC circuit LC1 includes a first inductor L1 and a first capacitor C1 connected in parallel for series with the positioning antenna 10 (see fig. 2). The second LC circuit LC2 includes a second inductor L2 and a second capacitor C2 connected in series. The second LC circuit LC2 is connected in parallel with the positioning antenna 10 by a ground.

The inductance values of the first inductor L1 and the second inductor L2 and the capacitance values of the first capacitor C1 and the second capacitor C2 may be appropriately set according to the frequency band to be attenuated (i.e., the first frequency band). This can be achieved by a person skilled in the art on the basis of common knowledge and experience, and will not be described in further detail here.

Fig. 6 and 7 show two examples of the circuit arrangement shown in fig. 4, respectively, in which the filter circuit comprises two band-pass filters.

Turning first to the circuit arrangement 300A shown in fig. 6. As shown in fig. 6, in the circuit device 300A, a power divider for outputting a positioning signal from the positioning antenna 10 to the first output circuit a and the second output circuit b is a first power divider 310. The filter circuit 340A includes a second power divider 341, a third power divider 342, and a first bandpass filter 343 and a second bandpass filter 344 connected in parallel between the second power divider 341 and the third power divider 342. The first band pass filter 343 is used to pass signals of a second frequency band and the second band pass filter 344 is used to pass signals of a third frequency band, the first frequency band being between the second frequency band and the third frequency band as discussed above. It can be seen that the first band pass filter 343 and the second band pass filter 344 in parallel form a band stop filter capable of attenuating signals in the first frequency band, which may be used, for example, to reduce interference of non-location signals with location signal reception and processing.

As shown in fig. 6, the filter circuit 340A may further include a blocking dc inductor 345 connected between the second power divider 341 and the third power divider 342 in parallel with the first and second bandpass filters 343 and 344. In this way, the filter circuit 340A can conduct a direct current to the positioning antenna 10, and thus can be used as a part of a feed circuit of the positioning antenna 10. In addition, the use of inductor 345 to provide a feed path for positioning antenna 10 also prevents useful positioning rf signals from flowing away through the feed power supply. In this way, a feeding power supply (not shown) of the positioning antenna 10 may be provided in, for example, the second output circuit b. Preferably, in the case where the glitch prevention false-positive short-circuit resistor 330 is provided in the second output circuit b, the feeding power supply may be provided on the side of the glitch prevention false-positive short-circuit resistor 330 close to the aircraft antenna receiver 20. Advantageously, according to an embodiment of the present invention, the positioning antenna 10 is allowed to be fed by the aircraft antenna receiver 20, i.e. the aircraft antenna receiver 20 is used as a feeding power supply for the positioning antenna 10, thereby making the overall circuit structure more compact and efficient.

Preferably, the second power divider 341 and the third power divider 342 are wilkinson power dividers so as not to obstruct the passage of the direct current. The first band pass filter 343 and the second band pass filter 344 can employ, for example, an acoustic surface filter.

In the example shown in fig. 6, the filtering circuit 340A may further include a first limiter 346 and a second limiter 347, where the first limiter 346 and the first band-pass filter 343 are connected in series between the second power divider 341 and the third power divider 342, and the second limiter 347 and the second band-pass filter 344 are connected in series between the second power divider 341 and the third power divider 342. The limiters 346, 347 described above prevent high power signals transmitted by the data link transmission module (not shown) from being conducted through the positioning antenna 10 to the aircraft antenna receiver 20, causing receiver blocking.

Preferably, the first limiter 346 and the second limiter 347 are located at a side closer to the antenna 10 with respect to the first band pass filter 343 and the second band pass filter 344, respectively, so as to further protect the band pass filters. For example, the tolerable signal level of part of the saw filter product is about 10dbm, while the image transmission signal transmitted by the data chain transmission module of the drone is coupled to the RTK positioning antenna and may reach around 20dbm after possible power amplification in the RTK receiving circuit; placing the limiters 346, 347 on the side of the band pass filter near the RTK antenna can effectively avoid, for example, the band pass filters 343, 344 being damaged by excessively strong image transmission signals.

Turning next to the circuit arrangement 300B of fig. 7. The circuit device 300B shown in fig. 7 has substantially the same structure as the circuit device 300A shown in fig. 6, except that: no traffic blocking dc inductor is included in filter circuit 340B of circuit arrangement 300B; and circuit arrangement 300B includes a blocking dc inductor 350 in parallel with filter circuit 340B. In the example shown in fig. 7, both ends of the anti-traffic direct inductor 350 are connected to the outer sides (the sides opposite to the band pass filters 343 and 344) of the second power divider 341 and the third power divider 342, respectively, so as to be connected in parallel with the second power divider 341 and the third power divider 342 and the circuit part connected therebetween (including the first band pass filter 343 and the second band pass filter 344).

Compared with the circuit device 300A shown in fig. 6, in the circuit device 300B shown in fig. 7, since the traffic blocking dc inductor 350 is not connected between the second power divider 341 and the third power divider 342, there is no requirement and limitation on the performance of the "on dc" of the second power divider 341 and the third power divider 342, which provides more convenience for circuit design.

It should be understood that, in the circuit apparatus 300B shown in fig. 7, the structure of the filter circuit 340B is merely exemplary, and the filter circuit 340B may adopt a circuit structure different from that shown in the figure.

The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of the invention as referred to in the present application is not limited to the embodiments with a specific combination of the above-mentioned features, but also covers other embodiments with any combination of the above-mentioned features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.