JP2928100B2 - Microwave landing guidance system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave landing guidance system, and more particularly to a horizontal radiation pattern of an azimuth guidance system.

[0002]

2. Description of the Related Art A horizontal radiation pattern of an azimuth guidance device in a conventional microwave landing guidance device is based on ANN of ICAO.
The pattern was a low side lobe satisfying the EX10 standard.

Next, as an example of a conventional azimuth guidance device for a microwave landing guidance device, a azimuth guidance device having a beam width of 3 degrees will be described with reference to the drawings.

FIG. 4 shows a radiation and current distribution pattern of a conventional azimuth guiding device having a beam width of 3 degrees realized by 78 elements.

[0005] The horizontal pattern of the antenna in the azimuth guidance device of the conventional microwave landing guidance device is a symmetric low side lobe pattern. Therefore, the current amplitude pattern 13,
The current phase pattern 14 mainly uses the Taylor distribution.

FIG. 5 is a system diagram of a conventional azimuth guidance device of a microwave landing guidance device using a regular array of 78 elements. The high frequency power input to the horizontal power supply circuit 15 is
The current is distributed to the phase shifters 9a,. The high frequency power input to the phase shifters 9a... 9n is given a phase shift amount corresponding to the beam scanning direction, and is fed to the vertical feeder circuit and the antennas 10a. Beam scanning control circuit (BS
U) 11 controls the amount of phase shift in the phase shifters 9a to 9n and scans the antenna radiation pattern.

The azimuth guidance device of the microwave landing guidance device performs a TO scan in which the beam directing direction is swung from left to right and a FRO scan in which the beam is swung from right to left at a certain timing. Scan and FR
It is possible to know the azimuth of the own aircraft from the azimuth guidance device of the microwave landing guidance device from the time interval of the O-scan.
However, the scanning direction is the one when the aircraft side is viewed from the antenna side.

[0008]

No beam formation is performed on the radiation pattern of the azimuth guidance device in the conventional microwave landing guidance device. Therefore, the rise is not steep in the radiation pattern formed by the azimuth guidance device of the conventional microwave landing guidance device.

When an airborne receiver receives a radio wave of a radiation pattern radiated from the azimuth guidance device, T
Since the reception detection threshold for detecting the start of the reception of the O scan and the FRO scan, that is, the trigger level varies, an error corresponding to the time when the reception level passes through the range of the variation occurs.

[0010]

An azimuth guidance device for a microwave landing guidance device according to the present invention is a horizontal power distribution device that forms a beam of an antenna radiation pattern and provides a current distribution for steepening a rising pattern in a scanning direction. It has a shifter, a phase shifter, a vertical feed circuit and an antenna, a beam scanning control circuit, and a switch for symmetrically switching the output of the horizontal feed circuit at the timing of the TO scan and the FRO scan.

[0011]

According to the present invention, the rise of the horizontal radiation pattern is made steeper than the fall, so that it can pass through the range of variation of the trigger level in the receiver mounted on the aircraft in a short time, and the azimuth detection error in the aircraft can be reduced. .

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a radiation and current distribution pattern according to one embodiment of the present invention. The radiation pattern 1 is a pattern of an embodiment in which the present invention is realized with 78 elements, and has a steep rising in the scanning direction.
The current amplitude pattern 2 and the current phase pattern 3 are examples for realizing the radiation pattern 1.

FIG. 2 is a diagram showing a radiation and current distribution pattern according to another embodiment of the present invention. Radiation pattern 4 is 120
This is a pattern in which the present invention is realized by the element, and is a radiation pattern with a steep rising in the scanning direction and a low side lobe. The current amplitude pattern 5 and the current phase pattern 6 are examples for realizing the radiation pattern 4.

FIG. 3 is a system diagram showing an azimuth guidance device of the microwave landing guidance device according to the present invention.

The high frequency power R input to the horizontal power supply circuit 7
The FIN is connected to the vertical power supply circuit and the antenna 10a so that the horizontal power supply circuit 7 has the current amplitude and current phase of FIG.
10n. In order to realize a steep radiation pattern at the rising edge of the scanning direction, the high-frequency input distributed by the horizontal power supply circuit is switched symmetrically at the timing of the TO scan and the FRO scan using the switch circuit 8, and then the phase shift is performed. 9n are input to the devices 9a... 9n. The high-frequency power is given a phase shift amount corresponding to the beam scanning direction by the phase shifters 9a to 9n, fed to the vertical feeding circuit and the antennas 10a to 10n, and radiated to the space.
The beam scanning control circuit (BSU) 11 is a phase shifter 9a.
The phase shift amount is controlled at 9n, and the antenna radiation pattern is scanned.

[0017]

The azimuth guidance device of the microwave landing guidance device of the present invention performs beam shaping of an antenna radiation pattern,
By making the rising pattern in the scanning direction steeper, the azimuth error can be reduced by passing the range of the variation of the trigger level on the receiver side in a shorter time. In the microwave landing guidance device, the beam width is determined to be 3, 2, or 1 degree, and the aperture length is uniquely determined when the conventional Taylor distribution is used. Since the antenna radiation pattern of the apparatus performs beam shaping, a steep rising pattern can be realized by increasing the aperture length, and the effect of reducing the azimuth error increases.

[Brief description of the drawings]

FIG. 1 is a diagram showing a radiation and current distribution pattern of an embodiment of an azimuth guidance device of a microwave landing guidance device of the present invention.

FIG. 2 is a diagram showing a radiation and current distribution pattern according to another embodiment of the present invention.

FIG. 3 is a system diagram of an embodiment of an azimuth guidance device of the microwave landing guidance device of the present invention.

FIG. 4 is a view showing a radiation and current distribution pattern of a conventional azimuth guidance device of a microwave landing guidance device.

FIG. 5 is a system diagram of an azimuth guidance device of a conventional microwave landing guidance device.

[Explanation of symbols]

1 ... radiation pattern (78
2) Current amplitude pattern (78 elements) 3 Current phase pattern (78 elements) 4 Radiation pattern (1 element)
20 elements) 5 Current amplitude pattern (120 elements) 6 Current phase pattern (120 elements) 7 Horizontal power supply circuit 8 Switch circuit 9a, 9b 9n Units 10a, 10b ... 10n ... vertical feeding circuit and antenna 11 ... beam scanning control circuit 12 ... radiation pattern (7
8 elements) 13 Current amplitude pattern (78 elements) 14 Current phase pattern (78 elements) 15 Horizontal power supply circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01S 7/00-7/42 G01S 13/00-13/95

Claims (3)

(57) [Claims] 1. A microwave landing guidance system, comprising: an aircraft;
Shorter trigger range variation for on-board receivers
A microwave landing guidance device having a horizontal feeding circuit that realizes an antenna current distribution that makes the rise of a horizontal radiation pattern steeper than the fall in order to pass in time . 2. The microwave landing guidance device according to claim 1, further comprising a switch circuit for symmetrically switching the output of the horizontal power supply circuit at the timing of the TO scan and the FRO scan. 3. A phase shifter for receiving an output of the switch circuit and controlling a phase shift amount in accordance with a beam scanning direction is provided for each vertical power supply circuit. 3. The microwave landing guidance device according to claim 2, wherein the microwave landing guidance device corresponds to the phase shift pattern described in (1).