JPH06169274A - Mobile satellite receiver - Google Patents

Abstract

PURPOSE:To receive a satellite broadcast in an excellent way on an aircraft by providing plural directional antennas, generating an antenna control signal from a navigation system, selecting an antenna and synthesizing received signals. CONSTITUTION:In a radome 1 at the outside of a shell, 12-sets of array antennas 3 are installed. Each antenna 3 is divided into 6X4 sets of blocks. Then a signal is converted into an intermediate frequency signal at an in-phase synthesis circuit and synthesized in phase and led to a signal synthesis section 9 in the shell as an output of one array antenna. On the other hand, a direction of a broadcast satellite is calculated from data of an inertial navigation system 5 installed in the aircraft in a control section and an available antenna 3 at preset is obtained and a control signal is given to the synthesis section 9. The synthesis section 9 selects an optimum signal among outputs of 12 antennas 3 based on the control signal from the control section 7 and the signals are synthesized in phase and the result is outputted. The satellite broadcast is observed on a monitor 13 by using a tuner 11 to select a channel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a satellite broadcast mobile receiving apparatus for favorably receiving radio waves from satellite broadcasts during flight.

[0002]

2. Description of the Related Art Devices relating to the reception of image information of satellite broadcasting while moving include trains, ships, buses, small passenger cars and the like, which have already been developed and are in a stage of practical use. Further, the tracking system of these devices is a mechanical tracking system or a combination of a mechanical tracking system and an electronic tracking system, and an all electronic tracking system device has not yet been developed.

[0003]

The satellite broadcasting receiver for an aircraft is required to be miniaturized because of restrictions on the installation location and the need to minimize the influence on the aircraft during flight. Further, from the viewpoint of reliability, it is necessary to eliminate a mechanically movable part of the tracking system and to install a part including an active element as much as possible in a pressurizing chamber with a good operating environment.

[0004]

In order to solve the above problems, a satellite broadcast mobile receiving apparatus of the present invention is provided. Therefore, the present invention arranges a plurality of array antennas in the radome by changing the direction of each array antenna so as to cover all the azimuth directions, and outputs the signal output of the array antenna that can be received according to the attitude of the aircraft. Two or more are selected, in-phase synthesis is performed in the intermediate frequency band, and all electronic tracking of broadcasting satellites is performed. At this time, the direction of the satellite is calculated by using the data of the inertial navigation device installed in the aircraft, and the tracking device such as the direction sensor of the receiving device is simplified. Further, regarding each array antenna in the radome, the array is further divided into a plurality of blocks, and the respective phases are combined in phase to perform electronic tracking in the elevation and azimuth directions. As a result, a substantially uniform gain is obtained in all azimuth directions, and wide-angle electronic tracking is realized even in the elevation direction. In addition, since all-electronic tracking eliminates mechanically moving parts, reliability against vibrations is improved, and high-speed satellite tracking is possible, making it stable even with complicated aircraft attitude changes. It becomes possible to receive satellite broadcasting. Also, a metal piece adhered to the surface of the radome to obtain a lightning protection effect greatly affects the transmission characteristics of radio waves in relation to the antenna installed in the radome, but multiple antennas are arranged in the radome. As a result, any of the antennas in the radome can always receive the radio waves of the broadcasting satellite at a high level with respect to the incoming radio waves in all directions, and the antennas of the present invention can be mounted by combining a plurality of antenna outputs. The satellite broadcast mobile receiving device can stably receive the radio waves of the broadcasting satellite in all attitude states of the aircraft.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. This satellite broadcasting mobile receiving apparatus is a radome 1 made of FRP, an array antenna 3 having directivity, an inertial navigation apparatus 5 for outputting navigation data during flight, and a control unit for generating a control signal for selecting the array antenna 3. 7 and a signal synthesizer 9 for in-phase synthesizing the outputs of the signals received by the array antenna 3. Further, as shown in FIG. 1, the control unit 7, the signal synthesizing unit 9, the tuner 11, and the monitor 13 are housed in the fuselage of the airplane, which is a pressurizing chamber, as shown in FIG. Then, only the array antenna 3 is installed outside the body and covered with the radome 1.

The inertial navigation system 5 uses
This is a device that determines the position and attitude of an airplane. It includes data such as the advancing direction, pitch angle, roll angle, altitude, latitude, and longitude data of the aircraft, along with other data necessary for aircraft operation.
It is generated by a 32-bit digital signal defined by the EEC (Aeronautical Electronics Commission). For example, the digital signal in FIG. 6 represents the current latitude of the aircraft.
This bit string is continuously output for other data according to a certain rule, and the control unit 7 first detects only the bit string of the data relating to the posture, altitude, and position necessary for the present invention. The type of information is defined by the label represented by the first 8 bits (bit 1 to bit 8) of the bit string, and in FIG. 6, the first 8 bits' 1100100
0'represents the label 310, and if such a bit is set, the control unit 7 detects this bit string as latitude data. If the first 8 bits are '110010
If it is 01 ', it becomes the label 311 and is detected as latitude data. The other data is also detected in the same manner. The control unit 7 detects a bit string of data required for antenna control by the label, and then creates concrete data from the bit string of bit 9 and thereafter. This data and RO
The processing logic written in M (Read Only Memory) produces a control signal for selecting the plurality of array antennas 3.

A lightning arrester 15 is attached to the wall surface of the radome 1. The lightning protection device 15 may be a belt-shaped member or a rod-shaped member made of metal, or may be a metal disk-shaped member arranged so as to be arranged appropriately. This lightning protection device 15
In order to reduce the influence of radio wave interference on the array antenna 3 due to, the array antenna 3 is arranged as far as possible from the lightning arrester 15. Further, during flight, the temperature inside and outside the radome 1 becomes substantially the same, and the temperature difference is extremely large.
As the substrate material of the array antenna 3, a composite rigid substrate of polyethylene and air that can obtain high gain and is not damaged even when decompressed, or a composite substrate material of polytetrafluoroethylene and glass fiber is used. This is because the present invention is premised on the use in high altitude where the atmospheric pressure is reduced to one-fourth that of the ground. Next, an example of the configuration of the satellite-borne mobile receiver for mounting on an aircraft according to the present invention will be described.
Twelve array antennas 3 inside the radome 1 outside the body
Set up. Each array antenna 3 is further divided into 6 × 4 blocks (not shown),
After being converted to an intermediate frequency by the in-phase synthesizing circuit 17, they are in-phase synthesized and guided to the signal synthesizing unit 9 in the body as an output of one array antenna. On the other hand, in the control unit 7,
The direction of the broadcasting satellite is calculated from the data of the inertial navigation device 5 installed in the aircraft, the currently receivable array antenna 3 is obtained, and the control signal is passed to the signal synthesis unit 9. The signal combiner 9 selects the optimum two or more signals from the 12 array antenna 3 outputs according to the control signal from the controller 7, and performs in-phase combining and outputs.

2 and 3 show an example of a method of installing the array antenna 3 in the radome 1 on the fuselage of the aircraft. In this example, twelve array antennas 3 each having a length a and a width b are installed with an angle difference of 30 degrees. In addition, the elevation angle direction is attached at an angle θ to the installation surface. Further, each array antenna 3 is divided into 6 × 4 blocks (not shown), and the received signals of all 24 blocks are in-phase combined to be the output of one array antenna 3. However, the number of array antennas 3, the installation angle, the number of divisions, the division method, and the like can be changed according to the directivity of the basic antenna element. FIGS. 7 and 8 show an example of the installation location of the radome 1 on an aircraft. The radome 1 is installed at the center of the horizontal part of the upper part of the fuselage so that the air resistance is minimized. A satellite broadcast can be viewed on the monitor 13 by demodulating the image signal with the tuner 11 and selecting a channel.

[0009]

As described above, the satellite broadcasting mobile receiving device for mounting on an aircraft according to the present invention can favorably receive satellite broadcasting on an aircraft. In addition, since the device uses the all-electronic tracking method, reliability is improved and high-speed sanitary tracking is possible.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

FIG. 2 is a plan view of an antenna installed in the radome 1 according to the embodiment of the present invention.

FIG. 3 is a side view of the antenna installed in the radome 1 according to the embodiment of the present invention.

FIG. 4 is a front view of an antenna according to an embodiment of the present invention.

FIG. 5 is a side view of the antenna according to the embodiment of the present invention.

FIG. 6 is a 32-bit digital signal data representing the latitude of an aircraft used for selecting the array antenna of the present invention.

FIG. 7 is a diagram showing an installation place of the radome 1 according to the embodiment of the present invention.

FIG. 8 is a diagram showing an installation place of the radome 1 according to the embodiment of the present invention.

[Explanation of symbols]

 1 Radome 3 Antenna 5 Inertial navigation device 7 Control unit 9 Signal combining unit 11 Tuner 13 Monitor 15 Lightning arrester 17 In-phase combining circuit

(72) Inventor Osamu Ono 1-6-5 Haneda Airport, Ota-ku, Tokyo (72) Inventor Hisashi Nakamura 1-6-5 Haneda Airport, Ota-ku, Tokyo

Claims (2)

[Claims] 1. A directional antenna means comprising a plurality of antennas arranged in a radome by changing the direction of each antenna so as to cover all azimuth directions; generating a navigation signal representing the position and attitude of an aircraft. A navigation device; a control unit for generating an antenna control signal for selecting an antenna to be received from the data of the navigation device; a antenna unit selected in response to the antenna control signal from the control unit to receive the received signal. A satellite broadcast mobile receiving device comprising a signal combining unit for in-phase combining. 2. The device according to claim 1, wherein the antenna means is installed on the fuselage outside the preload chamber of the aircraft,
A satellite broadcast mobile reception device including a radome covering the antenna means.