JP3443914B2 - Electronic scanning antenna - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mounted on the surface of an aircraft such as an aircraft, and is deformed due to a pressure difference between the inside and outside of the aircraft and vibration of the mounted aircraft, which affects the scanning beam performance of the antenna. Such an electronic scanning antenna.

[0002]

2. Description of the Related Art FIG. 10 is a diagram showing a structure of a conventional electronic scanning antenna. In FIG. 10, reference numeral 1 denotes a radio wave emitting portion of a thin electronic scanning antenna mounted on the surface of a body of an aircraft or the like, 2 denotes a plurality of transmitting and receiving antenna elements which are arranged on the surface of the radio wave emitting portion 1 and serve as entrances and exits of scanning beams Reference numeral 3 denotes a radio wave transmitter / receiver which is a transmission source of a scanning beam. FIG. 11 is a diagram showing a cross section of a conventional electronic scanning antenna, and FIGS.
Is the same as Reference numeral 11 corresponds to the transmission / reception antenna element 2, and a plurality of electronic circuit units for controlling the intensity and direction of the transmission / reception radio wave are respectively provided.
A connector 13 embedded in the inside is a circuit which is embedded in the radio wave radiating part 1 and distributes and synthesizes signals between the radio wave transceiver 3 and the electronic circuit unit 11 to transmit the signals. Reference numeral 20 is a mother body to which the radio wave radiation unit 1 of an aircraft or the like is attached. Here, the signal circuit 13 is embedded in the radio wave radiation unit 1,
There is also a method of directly connecting the radio wave transceiver 3 and the electronic circuit unit 11 with a cable or the like.

The conventional electronic scanning antenna is constructed as described above, and the electric wave emitted from the electric wave transmitter / receiver 3 is transmitted to the signal circuit 1.
3 is distributed and transmitted, is sent to the electronic circuit unit 11, is converted in the direction and intensity of the radio wave, and is connected to the connector 12
And is radiated to the outside from the transmitting / receiving antenna element 2. Radio waves from the outside enter the transmission / reception antenna element 2, are transmitted as signals in the opposite direction to the above, and are transmitted to the radio wave transmitter / receiver.

[0004]

In the electronic scanning antenna as described above, since the radio wave radiation part has a thin shape,
Deformation occurs due to the pressure difference between the inside and outside of the aircraft, vibration of the airframe, aerodynamic load, etc., which disturbs the direction of the scanning radio waves of the antenna, resulting in deterioration of performance such as strength and directionality of synthesized radio waves. was there.

Further, in order to prevent the deformation, it is usually considered to increase the rigidity of the antenna itself, but especially when it is mounted on an aircraft, weight reduction and downsizing are important functions. It is necessary to avoid increasing the mass by increasing

The present invention has been made to solve the above problems, and it is an object of the present invention to suppress the deterioration of the performance of transmitted and received radio waves even if the radio wave radiating section is deformed.

[0007]

In an electronic scanning antenna according to the present invention, a detection optical fiber that expands and contracts due to deformation of a radio wave emitting section and a reference optical fiber that is installed around the radio wave emitting section and does not expand and contract. Is embedded near the surface of the radio wave radiating section, and an optical transmitter for sending light to the optical fiber,
An optical receiver for comparing and detecting light intensities of the two kinds of optical fibers, a controller for analyzing and instructing a signal by the optical receiver, and a radio wave transmitter / receiver for exchanging signals with a transmitting / receiving antenna element.

Further, the detection optical fiber that expands and contracts due to the deformation of the radio wave emitting portion is formed into a waveform and embedded near the surface of the radio wave emitting portion.

[0009]

[0010]

[0011]

[0012]

The electronic scanning antenna configured as described above is
When there is no deformation in the radio wave radiating part, the light passing through each of the detection optical fibers interferes with the light passing through the reference optical fiber to generate a certain interference fringe. When the radio wave radiating portion is deformed, the detection optical fiber expands and contracts, a phase change occurs in the light passing through the inside, and the interference fringe with the reference optical fiber changes. Therefore, by detecting the amount of change, it becomes possible to control the intensity and direction of the scanning beam by the controller.

Further, by embedding a corrugated detection optical fiber which causes expansion and contraction near the surface of the radio wave radiating section,
The deformation is amplified to enable more accurate detection.

[0014]

[0015]

[0016]

[0017]

【Example】

Example 1. FIG. 1 shows an electronic scanning antenna according to an embodiment of the present invention. In FIG. 1, 1 to 3 are the same as or equivalent to the above conventional example. Reference numeral 4 is an optical transmitter arranged outside the radio wave emitting section 1, and 5 is an optical receiver arranged outside the radio wave emitting section 1. Reference numeral 6 is a detection optical fiber which is embedded near the surface of the radio wave emitting section 1 and which connects the optical transmitter 4 and the optical receiver 5 and which expands and contracts due to the deformation of the radio wave emitting section 1.
Reference numeral 7 connects the optical transmitter 4 and the optical receiver 5 in the same manner as the detection optical fiber 6, and is located around the radio wave radiating section 1 and also in an aircraft 1 or the like.
The reference optical fiber is embedded in a portion having high rigidity and small deformation such as a rib having the following structure so as to prevent expansion and contraction. It is necessary to confirm in advance by structural analysis or trial production that this buried place is small enough to be ignored as compared with the deformation of the radio wave radiation unit 1. The detection optical fiber 6 and the reference optical fiber 7 are arranged in a grid in the radio wave radiating section, and all the optical fibers connected to the same optical transmitter are adjusted to have the same length. Reference numeral 8 denotes a controller that analyzes the signal from the optical receiver and instructs the radio wave transmitter / receiver 3 to provide correction data for the scanning beam.

According to the electronic scanning antenna constructed as described above, the light emitted from the optical transmitter 4 is sent to the optical receiver 5 through the detection optical fiber 6 and the reference optical fiber 7. When the radio wave radiating section 1 is not deformed, the light passing through the respective detection optical fibers 6 interferes with the light passing through the reference optical fiber 7 to generate a certain interference fringe. FIG. 2 is an explanatory diagram showing the principle of generation of the interference fringes. In FIG. 2, 4,
Reference numerals 5, 6 and 7 are an optical transmitter, an optical receiver, an optical fiber for detection and an optical fiber for reference. Reference numeral 41 is a laser diode serving as a light transmitting element, 42 is a half mirror, 43 is a microlens, 51 is a photodiode serving as a light receiving element, and 55 is light passing through the detection optical fiber 6 and the reference optical fiber 7. Are interference fringes caused by interference. When the radio wave radiating section 1 is deformed to become like 1a, the length and the diameter of each of the detection optical fibers 6 are changed, and the phase change of the output light is caused by the change of the refractive index to cause the reference optical fiber 7 to be changed.
Since the interference fringes with the light passing therethrough are deformed, the deformation amount of the radio wave radiation unit 1 can be detected by analyzing the interference fringes.

Furthermore, since the detection optical fibers 6 are arranged in a lattice pattern and the amount of deformation of each optical fiber is detected by the optical receiver 5, the amount of deformation of the intersecting optical fibers causes
The area on the surface of the radio wave emission unit 1 can be specified. This is shown in FIG. In FIG. 3, when a certain point 101 on the radio wave radiating section 1 becomes 101a due to deformation, a certain amount of expansion and contraction also occurs in the detection optical fiber 6 near this point.
Since it becomes like a, it becomes possible to detect the deformation of the radio wave radiating unit 1 in an approximate manner. In the controller 8, the radio wave transmitter / receiver 3 receives data for correcting the intensity and direction of the scanning beam in accordance with the deformation amount of each surface area of the radio wave radiation unit 1.
Can be sent to. This correction data is shown in FIG.
As shown in (c), (a) the relationship between the light intensity and the deformation amount of the radio wave radiating unit 1, (b) the relationship between the deformation amount of the radio wave radiating unit 1 and the correction amount of the radio beam scanning direction, (c) the radio wave emission The relationship between the deformation amount of the unit 1 and the radio beam intensity correction amount is tentatively obtained in advance and stored in a storage device in the controller 8. The inclinations of the graphs of (a), (b), and (c) are determined by the difference in rigidity depending on the location of the radio wave radiation unit 1.

Example 2. FIG. 5 shows another embodiment in which the detection optical fiber 6 is embedded in the radio wave radiating section 1.
In FIG. 5, 1 to 5 and 7 and 8 are the same as those in the conventional example. In this embodiment, when the optical fiber 6 is embedded in the radio wave radiating section 1, by reciprocating along the surface, each optical fiber passes through the same region a plurality of times, so that smaller deformation can be detected. .

Example 3. FIG. 6 shows an electronic scanning antenna according to another embodiment of the present invention. Further, FIG. 7 shows a sectional view thereof. 6 and 7, 1 to
3, 11 to 13, 20 are the same as or equivalent to the above-mentioned conventional example. The electronic circuit unit 11 is omitted in FIG. 6 for convenience of illustration. Reference numeral 401 denotes a plurality of optical transmitters arranged around the radio wave radiating section 1, and a microlens is embedded in the light emitting section. Reference numeral 501 denotes a plurality of optical receivers arranged around the radio wave radiating section 1, and similarly, a microlens is embedded in the light receiving section. Reference numeral 9 is a laser light emitted from the optical transmitter 401, and reference numeral 9a is a laser light whose direction is changed by the deformation of the optical transmitter 401. The optical transmitter 401 and the optical receiver 501 are attached at positions that form a pair, and the optical transmitter 401 and the optical receiver 501 are arranged in the radio wave radiation unit 1 in a grid pattern. The laser beam 9 from the optical transmitter 401 is adjusted so as to enter the paired optical receiver 501 accurately.

According to the electronic scanning antenna configured as described above, the laser light 9 radiated from each optical transmitter 401 is transmitted to the paired optical receiver 501 when the radio wave radiation portion 1 is not deformed. Since the values are correctly entered, there is no difference in the received light intensity at the optical receiver 501. However, as shown in FIG. 4, when the radio wave radiating section 1 is deformed, the optical transmitter 401 installed on the radio wave radiating section 1 also moves spatially at the same time, so that the optical axis of the laser beam 9 becomes 9a. Move as shown, optical receiver 5
The amount of light input to 01, that is, the light intensity decreases or disappears. By detecting this light intensity, the amount of deformation of the radio wave radiating section 1 can be known. The relationship between the light intensity and the deformation amount of the radio wave radiating section 1 is obtained in advance as a test as in the first embodiment.

Further, an optical transmitter 401 and an optical receiver 501
Are arranged on the radio wave radiation unit 1 in a grid pattern, and the optical receiver 501 of the optical transmitter 401 and the optical receiver 501 which form a pair intersecting each other.
The area of the surface of the radio wave radiating part 1 can be specified by the amount of received light. The controller 8 can send data to the radio wave transmitter / receiver 3 for correcting the intensity and direction of the scanning beam according to the amount of deformation of each surface area of the radio wave radiation unit 1. Similar to the first embodiment, this correction data is obtained by tentatively obtaining the relationship between the deformation amount of the radio wave radiating section 1 and the intensity or direction of the scanning beam in advance and storing it in the storage device in the controller 8. Is.

Example 4. In the fourth embodiment, the optical transmitter 40
1 and the optical receiver 501 are mounted at positions that form a pair, but a mirror may be mounted at the position of the optical receiver 501. This is shown in FIG. Optical transmitter 401
The laser light 9 emitted from the laser beam is reflected by the mirror 6 and enters the optical receiver 501. As in the case of the fourth embodiment, when the radio wave emitting section 1 is deformed, the optical transmitter 401 installed on the radio wave emitting section 1 also moves spatially at the same time, so that the reflection angle at the mirror 6 is distorted. The incident amount on the optical receiver 501 changes.

Example 5. FIG. 9 shows a sectional view of an electronic scanning antenna according to another embodiment of the present invention. In FIG. 9, unlike the fourth and fifth embodiments, the optical transmitter 401 and the optical receiver 501 are located around the radio wave radiating portion 1 and in a portion having high rigidity and small deformation such as a rib which is a primary structure of an aircraft or the like. Will be placed. It is necessary to confirm in advance by structural analysis and trial production that the installation location is small enough to be ignored as compared with the deformation of the radio wave radiation unit 1. On the radio wave radiation unit 1 between the pair of optical transmitters and optical receivers, the light shield plate 15 is installed on the path of the light emitted from the optical transmitter 401. The light shield plate 15 has a small hole through which the laser light 9 can pass, and when the radio wave radiation part 1 is not deformed, the laser light 9 from the optical transmitter 401 passes through this hole and the optical receiver 501 receives it. It is adjusted so that it is accurately incident on. When the radio wave radiating section 1 is deformed, the light shielding plate 15 moves or tilts due to the deformation,
The amount of laser light 9 that passes through the hole in the light shield plate 15 is reduced or eliminated. In the optical receiver 501, the amount of deformation of the radio wave radiating section 1 can be known by detecting this light intensity.

[0026]

Since the present invention is constructed as described above, it has the following effects.

An optical fiber embedded in a grid pattern in the radio wave emitting portion detects the deformation amount of the radio wave emitting portion and sends data to the radio wave transceiver for correcting the intensity and direction of the scanning beam according to the deformation amount. Therefore, it is not necessary to particularly increase the rigidity of the radio wave emitting section, and accurate transmission / reception of a scanning beam can be performed with the thin and lightweight radio wave emitting section as it is.

Further, by embedding an optical fiber in the waveform in the radio wave radiating section, the deformation amount of the radio wave radiating section can be amplified and detected, so that more accurate scanning beam correction data can be obtained.

[0029]

[0030]

[0031]

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an electronic scanning antenna showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of light interference fringes according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a modification of the radio wave radiating section 1 showing the first embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a relationship between light intensity and correction data according to the first embodiment of the present invention.

FIG. 5 is an overall configuration diagram of an electronic scanning antenna showing a second embodiment of the present invention.

FIG. 6 is an overall configuration diagram of an electronic scanning antenna showing a third embodiment of the present invention.

FIG. 7 is a sectional view of an electronic scanning antenna showing a third embodiment of the present invention.

FIG. 8 is a sectional view of an electronic scanning antenna showing a fourth embodiment of the present invention.

FIG. 9 is a sectional view of an electronic scanning antenna showing a fifth embodiment of the present invention.

FIG. 10 is an overall configuration diagram of a conventional electronic scanning antenna.

FIG. 11 is a cross-sectional view of a conventional electronic scanning antenna.

[Explanation of symbols]

1 Radio wave emission part 2 Transmit / receive antenna element 3 radio wave transceiver 4 Optical transmitter 5 Optical receiver 6 Optical fiber for detection 7 Reference optical fiber 8 controller 9 laser light 10 mirror 15 Light shielding plate

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Claims (2)

(57) [Claims] 1. An electronic scanning antenna having a thin shape and having a plurality of transmitting and receiving antenna elements, wherein the detection optical fiber is embedded near the surface of the radio wave radiation part and expands and contracts as the radio wave radiation part is deformed. A reference optical fiber having no expansion and contraction installed around the radiation part, an optical transmitter for transmitting light to the optical fiber, an optical receiver for comparing and detecting the light intensities of the two kinds of optical fibers, The correction data of the intensity and direction of the scanning beam according to the deformation amount of the radio wave emitting unit is stored in advance, and the correction data of the scanning beam corresponding to the deformation amount of the radio wave emitting unit detected by the optical receiver is stored in the radio wave transceiver. An electronic scanning antenna comprising: a controller for instructing and a radio wave transmitter / receiver for exchanging signals with the transmitting / receiving antenna element. 2. The electronic scanning antenna according to claim 1, wherein the detection optical fibers are arranged in a waveform to have an amplification function.