JP4622898B2 - Antenna device - Google Patents

Description

  The present invention relates to an antenna apparatus, and more particularly to an antenna apparatus applicable to a radar that controls and monitors a flying object such as an aircraft on the ground, and particularly to a long-range radar apparatus for search radar.

  As a long-range radar device such as a radar for controlling and monitoring a flying object on the ground, a method of performing azimuth scanning or the like by a phased array and an antenna device using a rotary drive device are known.

FIG. 4 is a diagram showing a conventional phased array antenna device. The elements 101 are arrayed on a cylindrical peripheral surface, and a target is searched by forming a beam in the entire circumferential direction and the elevation angle direction by phase-controlling transmission / reception signals.
FIG. 5 is a diagram showing another conventional phased array type antenna apparatus. The phased array antenna in which the elements 102 are arranged in a plane is used in a plurality of directions in different directions so that the omnidirectional direction and the elevation angle direction are electronically scanned.
In these antenna devices, the number of antenna elements to be arranged becomes enormous, and the number of transmission / reception modules (TRM) directly connected to the antenna elements also increases and becomes extremely expensive. In addition, when scanning with a single beam, data in a specific direction can be acquired only once every round, and there is a problem that the data rate, which is the data acquisition speed in all directions and elevation directions, is low.

FIG. 6 is a diagram showing an antenna apparatus using a conventional rotation mechanism. It has a planar antenna structure in which two planar phased array antennas 111 and 112 are mounted side by side in the same direction on the rotary drive device 113, and the number of antenna elements is reduced compared to the phased array system shown in FIGS. Reference 1).
FIG. 7 is a diagram showing another antenna device using a conventional rotating mechanism together. This is an example of an antenna structure in which a parabolic antenna composed of a primary radiator 213 and main and sub-reflecting mirrors 211 and 212 is mounted back-to-back on a rotary drive device 214. Although the elevation angle direction is a phased array system, it can be configured at a relatively low cost by reducing the number of antenna elements, and the data rate can also be improved (see Patent Document 2).

  FIG. 8 is a diagram showing a power supply and signal transmission system of an antenna device that performs azimuth scanning by a rotary drive device. On the movable part of the rotary drive device, a phased array element 118, an amplifier 1 that supplies an RF signal to the element 118 via a circulator, an amplifier 2 that supplies an RF signal from the element 118 to a phase shifter, and transmission / reception are switched. A large number of transmission / reception circuits 117 including switches SW are provided, and it is necessary to supply an RF signal, a control signal, a power source, and the like via a mechanical movable contact between the fixed portion and the movable portion. For example, a rotary joint (R / J) 115 for transmitting an RF signal between a fixed part and a movable (rotating) part, a slip ring (S / S) for transmission of a power supply for an amplifier, a phase shifter, a control signal for SW, etc. / L) 116 is used. Therefore, for example, R / J and S / L are indispensable in an antenna device using a rotation mechanism as shown in FIG. 6 or FIG. 7, and these R / J and S / L have movable contacts. Deterioration of parts due to wear of the metal at the electrical contact point is unavoidable, and periodic replacement is necessary, resulting in high maintenance costs.

FIG. 9 is a diagram showing another example of an antenna device using a rotation drive device. An antenna 311 formed of a dipole antenna is fixedly disposed on a base 314 of a fixed part, and a main reflecting mirror 312 and a sub-reflecting mirror 313 are provided which are rotated about the antenna 311 by a movable part 315 rotated by a gear 316. A single beam rotating in the azimuth direction can be formed without using a rotary joint (see Patent Document 3).
JP 2003-207559 A JP-A-8-220213 JP-A-10-253746

  The use of an antenna configuration consisting of a parabolic reflector and a primary radiator for a long-range radar has the advantage that it can be provided at a lower cost than the phased array type, but the periodic time to capture the target There is a problem that the interval (data rate) is extended, which hinders search and tracking.

  In addition, in the antenna configuration in which the combination of the parabolic reflector and the primary radiator is mounted to reduce the data rate, the device becomes larger, and the antenna circuit on the movable portion that rotates from the fixed portion of the rotary drive device Electrically movable contacts, such as rotary joints for numerous RF signals, control signals and power supplies, etc. are required.

  In this regard, the antenna apparatus shown in FIG. 9 has an advantage that a rotary joint or the like is not necessary. However, in the antenna apparatus shown in FIG. 9, the dipole antenna 311 and the sub reflector 313 are separated from the main reflector 312 and the free space. Therefore, there is a problem that the radio path is shielded, the efficiency is lowered, and the side lobe is deteriorated. In addition, since it is composed of a single antenna device, there is a problem in that the data rate is extended to hinder search and tracking. Furthermore, there is a problem that the antenna to be used is a dipole antenna and elevation angle scanning cannot be performed.

(Object of invention)
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems. In a reflector type antenna device that performs azimuth scanning with a rotary drive device, an electric movable contact is eliminated and radio waves between the reflector and free space are eliminated. An object of the present invention is to provide an antenna device configured such that the primary radiator does not shield the path.

  Another object of the present invention is to eliminate the need for an electrically movable contact in a reflector type antenna device that performs azimuth scanning with a rotary drive device, and enables the formation of a plurality of beams by sharing a primary radiator. An object of the present invention is to provide an antenna device that can shorten the time.

  Another object of the present invention is to provide a reflector type antenna device that performs azimuth scanning with a rotary drive device, performs elevation angle scanning with a phased array method, and transmits a feed joint RF signal to a rotary joint, an amplifier power source, and a phase shifter. An object of the present invention is to provide an antenna device suitable for a reflector-type long-range radar device that does not require the use of a slip ring for transmission of control signals for equipment.

  In order to achieve the above-mentioned object, the present invention relates to a long-range radar apparatus having a rotational drive mechanism that mechanically rotates in a horizontal plane and capable of target scanning of an azimuth by this rotation, and a primary radiator is fixed. The offset reflecting mirror is mechanically rotated on the outer periphery of the lever to eliminate the use of electrically movable contacts such as a rotary joint (R / J) and slip ring (S / L). Further, a plurality of offset reflecting mirrors are arranged at equal positions on the outer periphery with the primary radiator as the center, and are mechanically rotated. The reflector is an offset parabolic curved surface and is arranged so that radio wave radiation avoids shielding of the primary radiator, and the primary radiator is composed of phased arrays that can vertically scan the beam in the elevation direction by arranging the elements vertically. A plurality of phased arrays are arranged in a circle, and a switch (SW) is synchronized with the rotation of the reflecting mirror so that a radio wave is emitted when a radiating element of any phased array faces each of the reflecting mirrors. It is configured so that optimum irradiation is always continued to the reflecting mirror by sequentially switching with the transmission / reception circuit.

  The antenna device of the present invention is an antenna device that performs azimuth scanning by rotating a reflecting mirror by a rotational drive mechanism that mechanically rotates in a horizontal plane, and a primary radiator is fixedly arranged, and a radio wave on a reflecting surface by the primary radiator is provided. A reflecting mirror arranged at a position avoiding the shielding of the road is rotated around the primary radiator by the rotation drive mechanism, or the primary radiator is fixedly arranged, and the entire circumference around the primary radiator is divided equally. A plurality of reflecting mirrors forming a plurality of beams arranged at the positions are rotated by the rotation driving mechanism. The reflecting mirror has a reflecting surface formed by an offset parabolic curved surface, and the primary radiator is configured by arranging a plurality of phased arrays capable of electronically scanning a beam in an elevation angle direction in which a plurality of radiating elements are arranged vertically, The phased array is arranged on a circumference, and a plurality of switches for switching and connecting a plurality of radiating elements of a phased array in a column facing the rotating reflecting mirror and a transmitting / receiving circuit side such as a transmitting / receiving module in synchronization with rotation. It is characterized by providing.

(Function)
In an antenna device that uses a rotating reflector, the primary radiator is fixed to eliminate the electrically movable contact, and the reflector focuses the beam in a direction different from the incident angle from the primary radiator by a fixed angle as an offset structure. Radiate and avoid shielding radio paths with primary radiators. In addition, a plurality of offset reflecting mirrors arranged at positions that equally divide the outer circumference of the primary radiator are mechanically rotated, and power is supplied to the plurality of elements by a switch (SW) in synchronization with the rotation of the reflecting mirrors. Switch, always irradiate each mirror with a beam to form a rotating beam and simultaneously search in multiple directions. The primary radiator is a phased array antenna composed of a plurality of elements, and enables a target search in all directions and in the elevation direction (also simply referred to as the elevation direction) in the upper and lower limits.

  According to the present invention, in an antenna device that uses a rotating reflector, the primary radiator is fixedly arranged, and an offset structure is used as a reflecting mirror that rotates around the primary radiator. By arranging the radio wave path of the reflecting surface in a position that does not shield the radio signal, it is possible to eliminate an electrically movable contact for transmitting an RF signal, etc., and to prevent a decrease in antenna efficiency, a deterioration in side lobe, etc. It is possible to realize antenna performance suitable for the above.

  According to the present invention, the data rate can be improved by using a plurality of reflecting mirrors sharing the primary radiator, and the data rate in all directions and elevation directions can be improved by making the primary radiator a phased array. Can be planned. In other words, by using a plurality of reflectors at the position where the entire circumference around the primary radiator is equally divided, it is possible to form a plurality of beams, and simultaneously search in a plurality of directions, so that an azimuth direction and an elevation angle direction can be obtained. It is possible to reduce the time required for scanning.

  Furthermore, since it is possible to fix the primary radiator, a rotary drive device that does not use parts with heavy contact wear such as electrical parts such as a rotary joint (R / J) and slip ring (S / L) can be realized. . As a result, regular replacement of R / J, S / L, etc. becomes unnecessary, and maintenance costs are reduced.

(Description of configuration)
Next, an antenna device according to an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a configuration of the present embodiment. The present embodiment includes a reflecting mirror 11, a primary radiator 12, and a rotation driving device 13. The rotation driving device 13 is a mechanism for mounting the reflecting mirror 11 on the top and rotating the horizontal plane, and includes a fixed portion 13a and a movable portion 13b as a rotating disk. In the present embodiment, an example in which the reflecting mirror 11 is constituted by three reflecting mirrors 11a, 11b, and 11c is shown.

  The primary radiator 12 is fixedly arranged perpendicularly to the fixed portion 13a so as to pass through an opening (through hole) formed at the center position of rotation of the movable portion 13b of the rotary drive device 13, and the plurality of reflecting mirrors 11 are provided with primary radiation. Each of the reflecting surfaces has a focal point (line) at or near the primary radiator 12 at positions on the movable portion 13b (in this example, an angular interval of 120 °) that equally divides the outer periphery centered on the radiator 12. An offset parabolic curved surface is formed.

  The primary radiator 12 fixed to the fixed portion 13a of the rotation drive device 13 irradiates the reflecting mirror 11 rotating around on the movable portion 13b, and the plurality of reflecting mirrors 11 offset the irradiated radio waves in an offset shape. A plurality of sharp beams reflected and rotated by a parabolic curved reflecting surface are formed. The primary radiator 12 and the reflecting mirror 11 realize a high gain antenna device.

  FIG. 2 is a diagram showing a specific configuration example of the primary radiator, in which (a) is an antenna structure diagram and (b) is a feed system diagram. The primary radiator 12 is provided with a pillar 120 fixed to the fixed portion 13a at the center, and an antenna element 121 having a structure in which a plurality of elements (radiating elements) are arranged at equal intervals on the circumference around the pillar 120, 122n... 12n includes an antenna structure in which a plurality of stages are arranged in the vertical direction (vertical direction).

  The feeding of RF signals to the plurality of elements of the antenna element and the transmission of the phase control signal and the like are performed directly from, for example, a transmission / reception module (TRM) provided in the fixed portion 13a or directly from a TRM connected via the fixed portion 13a. Can be configured. A plurality of elements (radiating elements) in the vertical direction form a phased array in which the beam is scanned in the elevation direction by a phase shifter built in the TRM. The TRM 14 is a component used in the phased array and is well known to those skilled in the art, so a more detailed description is omitted.

  In addition, each element of the antenna elements of each stage arranged in a cylindrical shape is 120 ° by three switch (SW) configurations in synchronization with the rotation of the plurality of reflecting mirrors 11a, 11b, and 11c (rotation of the movable portion). The signal is switched and supplied to the element at an angular interval of 3, and the radio waves are always irradiated to the three reflecting mirrors 11a, 11b, and 11c.

  The arrangement configuration of the antenna elements described above is a configuration in which a plurality of radiating elements are arranged vertically and phased arrays capable of electronic scanning of the beam in the elevation angle direction are arranged in a plurality of rows, and the phased arrays are arranged on the circumference, A plurality of radiating elements in a phased array in a row facing the three reflecting mirrors rotating and a transmitting / receiving circuit side such as a TRM are switched and connected in synchronization by three switches. The three reflecting mirrors have a configuration in which an optimum radio wave is always radiated from a plurality of radiating elements arranged vertically at the respective linear focal points (lines).

(Description of operation)
Next, beam formation on the horizontal plane and the vertical plane of the antenna device of this embodiment will be described.
FIG. 3 is a diagram showing the beam forming operation of the horizontal plane according to the present embodiment. (A) shows the beam switching state of the primary radiator, and (B) shows the radio wave path.

  In the example of the antenna element 121 shown in FIG. 2, the switch contacts 1212a to 1212c on the output side of the TRM 14 rotate in synchronism with the rotation direction of the parabolic curved reflecting mirrors 11a, 11b, and 11c to generate primary radiation. The signal is switched and supplied to each vertical element of the device 12. As a result, the relationship in which the reflecting mirrors 11a, 11b, and 11c are positioned in the beam directions of the elements 1211a to 1211c to which signals are fed from the switch contacts 1212a to 1212c is maintained.

  For example, as shown in FIG. 3A, in the state where the output of the TRM 14 is supplied to the elements 1211a to 1211c from the switch contacts 1212a to 1212c, the beams I of the elements 1211a to 1211c are respectively reflected by the reflecting mirrors 11a to 11c. Formed in the direction. The radio waves radiated from the respective elements 1211a to 1211c are irradiated to the reflecting mirrors 11a to 11c, respectively, and the radiated radio waves are converged by the reflecting mirrors 11a to 11c to become a sharp beam.

  Then, the switch contacts 1212a to 1212c are rotated in synchronization with the reflecting mirrors 11a to 11c, and the beam switching of the primary radiator 121 is controlled to thereby synchronize with the rotation of the reflecting mirrors 11a to 11c. Elements arranged on the circumference are sequentially switched as radiating elements, and the primary beam 15 of the primary radiator 121 is always formed facing the respective reflecting mirrors 11a to 11c in the order of I → II → III.

  By performing the control to switch the power feeding to the antenna element by the switch SW in this way, as shown in FIG. 3B, the rotating three reflecting mirrors 11a to 11c and the rotating beam of the antenna element 121 are relative to each other. The positional relationship is maintained and maintained without change, and three rotating beams are formed.

  The above operation of the antenna element 121 is the same for the other antenna elements 122 to 12n arranged on the support column 120 together with the antenna element 121. However, the signal phase is changed between the antenna elements by the TRM 14 between the antenna elements 121 to 12n. Since it is controllable, the three beams formed by the primary radiator 121 can control scanning in the elevation direction.

In this embodiment, the movable contact is eliminated, and there is no need to perform it via the power supply system RF signal R / J, the amplifier power supply, the phase shifter control signal S / L, or the like, and component deterioration due to wear of the metal at the contact point And get out of regular exchanges.

  In addition, the reflecting mirrors 11a to 11c can select the radio path by avoiding the shielding of the primary radiator by using the offset parabola on the reflecting surface, and can avoid the deterioration of efficiency and the side lobe. .

(Another embodiment of the invention)
In the above-described embodiment, an example of using three reflecting mirrors has been described. However, the number of reflecting mirrors can be further increased by selecting positions and dimensions that can prevent shielding of the primary radiator. In addition, although a plurality of beams considering the reduction of the data rate have been described as the antenna for the long-range radar apparatus, the case of one beam can be applied to avoid the use of R / J and S / L.

  The configuration and operation of the above embodiment are basically the same when receiving radio waves, and the formation of multi-beams during reception is realized by using the primary radiator for receiving radio waves.

It is a figure which shows one Embodiment of the antenna device of this invention. It is a figure which shows the structural example of the primary radiator of this Embodiment, (A) is a structure, (B) is a signal system | strain. It is a figure which shows the radio wave radiation | emission operation | movement of the primary radiator of this Embodiment, (A) is a primary radiator beam switching condition, (B) is a radio wave path. It is a figure which shows the example of a cylindrical phased array antenna. It is a figure which shows the example of another phased array antenna. It is a figure which shows the example which used several planar phased arrays. It is a figure which shows the example which used the parabolic antenna for multiple surfaces. It is a figure which shows the electric power feeding system diagram of the antenna apparatus which has a mechanical rotation mechanism. It is a figure which shows the other example of the antenna apparatus using a rotation mechanism.

Explanation of symbols

11 (11a, 11b, 11c), 212 Reflector 12, 213 Primary radiator 13, 113, 114, 214 Rotation drive device 13a Fixed portion 13b, 315 Movable portion 14 TRM
15 Beam 101, 102, 118 Element 111, 112 Phased array 115 Rotary joint R / J
116 Slip ring S / L
120 Posts 121, 122,... 12n Antenna elements 1211a, 1211b, 1211c Elements 1212a, 1212b, 1212c Switch contacts 211, 312 Main reflector 212, 313 Sub reflector 314 Base 311 Antenna 316 Gear

Claims (6)

In an antenna device that performs azimuth scanning by rotating a reflecting mirror by a rotational drive mechanism that mechanically rotates in a horizontal plane,
An antenna characterized in that a primary radiator is fixedly arranged, and a plurality of reflecting mirrors that form a plurality of beams arranged at equally spaced positions around the primary radiator are rotated by the rotation driving mechanism. apparatus. The reflector antenna system of claim 1, wherein the reflecting surface is offset parabolic curved surface. 3. The antenna apparatus according to claim 1, wherein the primary radiator is configured by arranging a plurality of phased arrays in which a plurality of radiating elements are vertically arranged and capable of electronically scanning a beam in an elevation angle direction. The phased array includes a plurality of switches arranged on a circumference and configured to switch and connect a plurality of radiating elements of a phased array in a column facing the rotating reflecting mirror and a transmitting / receiving circuit side in synchronization with rotation. The antenna device according to claim 3 . The rotational drive mechanism includes a fixed portion and a movable portion having an opening (through hole) in the center. The primary radiator passes through the opening of the movable portion and is fixedly disposed on the fixed portion. the antenna device of any one of claims of claims 1 to 4, characterized in that disposed on the movable portion. Claims 1, characterized in that applied to long range radar antenna system of any of the claims 5.

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