JPS6211307A - Antenna for iff interrogator of aircraft - Google Patents

Abstract

PURPOSE:To avoid hindrance which might be caused when an identification friend or foe (IFF) interrogator is provided on a radar antenna by providing a microstrip antenna to a insulator part of the front ridge of main wing and a blade antenna on and beneath the fuselage so as to form the IFF interrogator. CONSTITUTION:The microstrip L band antenna 1-4 are provided to the insulator 15 of the front ridge of both wings and blade L band antennas 5, 6 are provided on and beneath the fuselage and they are used for the IFF interrogator for an object caught via the radar antenna 14. Then the antennas 1-4 are scanned synchronously with the turning of the antenna 14 by phase shifters 8-11 subject to phase control by a computer 12, a hybrid circuit 7 operates a pattern being a difference the total sum of signals from the antennas 1-6 and the notch at the center so as to eliminate an undesired replay wave from directions other than the beam direction and multi-path from the sea surface. Since the constitution is adopted that the antennas for the interrogator are not provided on the radar antenna, hindrance such as deteriorated characteristic of the radar antenna and damage to the antennas for the interrogator attended with the turning of the radar antenna is avoided.

Description

Detailed Description of the Invention [*Yu I-'s Haku1da A-cup] This invention relates to an antenna for an IFF interrogation device installed in various aircraft.

[Conventional technology]

Sento aircraft IFF (Identifica Lion F
r1end or Foe) An interrogation device is a device that identifies targets detected by radar. The antenna of the IFF interrogation device is a dipole type antenna, and as shown in Fig. 4, several dipole type antennas 20 of L-band frequency are attached to the radar antenna 14 in combination, and the signal from the antenna is processed by monopulse processing. The antenna beam width is relatively narrowed by forming sum and difference patterns.

[Problem that the invention seeks to solve]

The presence of the IFF antenna degrades the performance of the radar antenna, and since the IFF antenna feed line is fixed to the radar antenna, it is bent as the radar antenna rotates, resulting in deterioration.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention arranges IFF antennas at the leading edges of the main wings of the aircraft and above and below the fuselage, and controls the phase of the antenna beam for scanning.

There is no effect on the radar antenna, and multipath countermeasures can be taken. That is, 9 the present invention uses a part of the leading edge of the left and right main wings of an aircraft as an insulator, 9 a microstrip type antenna affixed to this part, 9 two blade type antennas installed above and below the fuselage of the aircraft, and the above-mentioned. A phase shifter that scans the signal of the microstrip antenna in synchronization with the rotation of the radar antenna, a control device that controls the phase of the phase shifter, and a control device that inputs the signals of the microstrip antenna and the blade antenna, and inputs these signals. The present invention provides an antenna for an IFF' interrogation device for an aircraft, characterized in that it is equipped with an arithmetic circuit that calculates a depressed difference pattern in the center from a combined sum pattern and the signals of these antennas.

〔Example〕

FIG. 1 is a perspective view of an antenna for an aircraft IFF interrogation device according to the present invention, and FIG. 2 is a circuit configuration diagram thereof.

Aircraft main wing leading edge made of fiberglass plastic (FRP)
15, and a microstrip-type L-band antenna 1.2.8.4 is pasted on its surface, and blade-type blade antennas 5 and 6 can be attached to the top and bottom of the fuselage. This blade type L-band antenna 5゜6 is connected to the signals of these blade antennas and the microstrip type L-band antenna 1.
．． This is to remove unnecessary response waves (multipulse, etc.) from above and below by subtracting the signals in 2.3.4. 14 is a radar antenna, and 16 is a radome for the radar antenna. In FIG. 2, each antenna 1.
The hybrid circuit 7 is configured to obtain the composite sum (2) of 2.8.4.5.6 and a pattern with a depressed difference (c) in the center as shown by 13 in FIG. On the other hand, it is composed of 7A shifters 8, 9, 10, 11 for electronic scanning of the antenna beam in the azimuth direction, and a computer 12 for controlling the phase thereof. This phase shifter adjusts the phase of radio waves transmitted from each antenna 1.2.8°4 to obtain 9 composite antenna patterns.
This is to shift the phase in accordance with the direction of 4 and make the radio waves of each antenna parallel. The phase control computer 12 obtains the antenna azimuth signal from the radar antenna 14.

Next, the operation of the embodiment will be explained.

A typical example of an antenna pattern is shown in FIG. 3, and the beam of the IFF antenna pattern scans in the azimuth direction in synchronization with the rotation of the radar antenna.

On the other hand, by subtracting the difference pattern 18 from the sum pattern 17, which is the sum of all antenna signals 1 to 6, unnecessary response waves other than those in the beam direction are removed. Furthermore, a difference pattern is formed in the Nilevageron direction to eliminate multipaths from the sea surface.

The above-mentioned difference pattern 18 is a notch pattern created by the hybrid circuit 7 with a dip in the center from the signals of all the antennas 1 to 6, and is called a difference pattern.

When this difference pattern 13 is subtracted from the sum pattern 16, only the signal at the center of the sum pattern 16 remains, and the side lobes of the sum pattern are removed.

〔Effect of the invention〕

According to the above-described antenna for an aircraft IFF interrogation device of the present invention, the following effects can be obtained.

(]) Since there is no IFF antenna on the radar antenna, there is no performance deterioration, and the radar antenna radome does not need to pass L-band radio waves, so the design is simplified.

(2) The IFF antenna has a simple structure that is attached to the FRP on the leading edge of the main wing, so it has little effect on the internal structure of the aircraft.Furthermore, since the antenna beam at the elevation is narrowed, there is no effect of multipath.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an antenna for an IFF interrogation device of an aircraft according to the present invention, FIG. 2 is a circuit diagram thereof, and FIG. 3 is an antenna pattern of the IFF interrogation device. 1.2, 8, 4: Micro strip type L band antenna, 5, 6: Blade type L band antenna, 7: High prism circuit, 8, 9, 1011: Phase shifter, 1
2: Computer. No. 71!1 2nd circle Figure 3 4th procedural amendment (method) % formula % Incident display 1985 Patent application No. 150991
Title of the No. Invention Relationship with the case involving a person who corrects antennas for aircraft IFF interrogation devices Address of patent applicant No. 1, 5-5, Marunouchi 2-chome, Chiyoda-ku, Tokyo Name (62G) Representative of Mitsubishi Heavy Industries, Ltd. Address Tokyo 2-51tq Marunouchi, Chiyoda-ku, Miyako
Page 7 of the specification, line 4, ``... Shows the antenna pattern'' has been replaced with ``... A diagram showing the antenna pattern B-7. Figure 4 is a diagram showing the IFF of a conventional aircraft. A perspective view of the antenna for the interrogation device is shown.''

Claims (1)

[Claims] A part of the leading edge of the left and right main wings of the aircraft is an insulator, and a microstrip type antenna is attached to this part, two blade type antennas are installed on the top and bottom of the fuselage, and the signal of the microstrip type antenna is attached to this part. a phase shifter that scans in synchronization with the rotation of the radar antenna, a control device that controls the phase of the phase shifter, a sum pattern that inputs the signals of the microstrip antenna and the blade antenna, and synthesizes these; 1. An antenna for an IFF interrogation device of an aircraft, comprising: an arithmetic circuit for calculating a difference pattern in which a center portion of the antenna is depressed from a signal of the antenna.