JP3500524B2 - Mobile satellite communication antenna - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna used for communication using a satellite in a land mobile such as a truck or a bus or a marine mobile such as a ship. More specifically, the present invention relates to an antenna used to receive a GPS radio wave arriving from a GPS satellite and transmit and receive a communication radio wave to and from a communication satellite for communication using the communication satellite. 2. Description of the Related Art Many GPS satellites orbit around the earth, and when viewed from the ground, various numbers of the GPS satellites exist in various directions according to time and place. Therefore, in order to receive GPS radio waves, an omnidirectional antenna is used so that all GPS radio waves from GPS satellites in various directions can be received. On the other hand, since the above-mentioned communication is performed using a specific geostationary communication satellite, an antenna having a high directivity is used as a communication antenna so that communication radio waves can be efficiently transmitted and received toward the geostationary communication satellite. Moreover, since the moving body, for example, a truck changes its direction in various directions as it travels, the communication antenna can rotate an antenna element for transmitting and receiving communication radio waves in a horizontal plane to a case for mounting on a truck. Use the one that has been used. The GPS antenna and the communication antenna are arranged in such a manner that each antenna does not block the radio wave of the other antenna and can perform proper reception of the GPS radio wave and proper transmission and reception of the communication radio wave, as shown in FIG.
As shown in the figure, the GPS antenna 21f and the communication antenna 18
and f are spaced apart from each other. [0003] However, as described above, G
In order to dispose the PS antenna 21f and the communication antenna 18f apart from each other, when they are mounted on the truck 54f, there is a problem that the mounting work of the two antennas 21f and 18f requires labor and time. there were. When selecting the installation location of the two antennas 21f and 18f, not to mention a place where the surroundings are not obstructed, as well as in the mutual relationship between the two antennas 21f and 18f, as described above, so as not to interrupt the radio waves of the other party. There is a problem that it is difficult to select each installation location because it must be arranged. In order to satisfy the mutual relationship between the two antennas 21f and 18f, there is also a problem that a large space is required for installation. The present invention has been made to solve the above-mentioned problems (technical problems) of the prior art.
In the case of mounting on a mobile object, simply attach the base frame of the communication antenna to the mobile object and automatically attach the GPS antenna, so that the installation work can be easily performed with only one antenna installation time It is an object of the present invention to provide a mobile satellite communication antenna capable of performing the following. A second object of the present invention is to provide an antenna for mobile satellite communication in which the location can be selected based on a very simple selection criterion of arranging one antenna in a place where the surrounding area is not obstructed when selecting a mounting location. It is to provide. A third object of the present invention is to provide a mobile satellite communication antenna in which the space required for the mounting location can be reduced to a narrow space necessary for mounting one antenna. The fourth object is that mounting to a moving body can be performed with the feeling of one antenna as described above, the mounting work is simple, and the installation location can be easily selected.
In addition, even if the installation space is narrow and sufficient, it is possible to provide a mobile satellite communication antenna that can properly receive GPS radio waves and transmit and receive communication radio waves in the installed state. is there. [0005] In order to achieve the above object, a mobile satellite communication antenna according to the present invention comprises:
A radome with a space for receiving antenna elements is placed on the base frame that has a mounting part to the moving body, and in the space surrounded by the radome, communication radio waves are transmitted and received toward communication satellites. A communication antenna element for communication is provided rotatably in a state facing the peripheral side wall of the radome, and a large number of GPS satellites are provided on the top of the radome avoiding the region of the peripheral side wall through which the communication radio wave passes. GPS coming from
It is provided with a GPS antenna element for receiving radio waves. A satellite communication antenna is attached to a mobile object.
The installation is completed by only selecting one mounting place on the moving body and mounting the base frame there. The GPS radio waves arriving from many GPS satellites in the mounted state can be received by the GPS antenna element provided on the top of the radome without being interrupted by any other object. Further, by turning the communication antenna element toward the satellite by turning the communication antenna element, communication electric waves can be transmitted and received through the peripheral side wall of the radome without being blocked by the GPS antenna element. An embodiment of the present invention will be described below with reference to the drawings. 1 to 3, reference numeral 1 denotes a satellite communication antenna. Reference numeral 2 denotes a base frame of the antenna 1, which forms a case provided with a housing space 2a for housing a communication circuit, a GPS receiving circuit, and the like in the antenna, and has a robustness and an ingress of water into the inside. It is configured to have a shielding function. The base frame 2 is made of, for example, aluminum die casting for such a purpose, but may be made of a rigid synthetic resin. 3
Is a mounting portion for a moving body provided on a base frame, and has a structure including a contact surface 4 to the moving body and a screw hole 5. Reference numeral 6 denotes a flange for fixing the radome, which is provided with a waterproof packing.
Reference numerals 7 and 8 denote boards mounted on the base frame 2. The board 7 is for holding the communication antenna element 18 and the rotating device 23 for rotating the same, and the board 8 is a communication circuit, a GPS receiving circuit, etc. It is for mounting. Next, reference numeral 10 denotes a radome for protecting the antenna element from rainwater and dust, and a space 11 for accommodating the antenna element is provided on the inside, which is a rigid material that transmits GPS radio waves and communication radio waves, such as polycarbonate or the like. It is formed of a resin material. Reference numeral 13 denotes a holding member for holding the GPS antenna element. Reference numeral 14 denotes a flange for connection with the base frame, which is superposed on the flange 6 with the packing interposed therebetween, and is fixed to the flange 6 by a fixing band 15. Reference numeral 18 denotes a communication antenna element provided in the space 11, which is rotatably mounted on the substrate 7 with the opening 19 facing the peripheral side wall of the radome 10. As the communication antenna element 18, an antenna having a high directivity is used so that communication radio waves can be efficiently transmitted and received toward a specific communication satellite. Although a pillbox antenna is shown as an example, a microstrip antenna may be used instead.
Reference numerals 20 and 20a indicate paths of communication radio waves transmitted and received by the communication antenna element 18. α indicates the vertical opening angle of the passage 20, and β indicates the lower limit angle of the passage 20, and these are communication points within the range of the passage 20 in any area within the expected moving range of the moving body. To be able to catch the communication satellite of For example, in Japan, when a geostationary communication satellite is used as a communication satellite for communication, the elevation angle is set to about 40 ° and β is set to about 15 ° since the elevation angle is 30 ° to 50 ° depending on the region. Γ in FIG. 3 indicates the horizontal opening angle of the passage 20a, which is, for example, about 3 ° in the case of the pill box antenna. As the communication satellite for communication, when a communication satellite orbiting the earth arrives within the range of the elevation angle, the communication satellite may be used. Reference numeral 21 denotes a GPS antenna element. A non-directional, for example, microstrip antenna is used so that GPS radio waves arriving from any direction can be received. The top portion avoiding the region 12 of the peripheral wall, for example, is disposed on the rotating shaft 18a of the communication antenna element 18, and is held by the holding member 13. 22 is the GP received by the antenna element 21
A transmission line for transmitting the S signal, which can transmit the GPS signal (for example, 1.5 GHz) with little attenuation, and has a narrow transmission line such as a 2.7 mm diameter 2 .5D coaxial cable is used. Reference numeral 23 denotes a rotation device for rotating the communication antenna element 18, which is a motor capable of appropriately controlling the rotation angle, for example, a stepping motor 24, and is attached to the rotation shaft. Pulley 25 and communication antenna element 18
Pulley 27 and both pulleys mounted concentrically with the center of rotation 18a of the
An example is shown in which the belt 26 is connected to the belts 25 and 27.
Reference numeral 30 denotes a communication circuit, reference numeral 31 denotes a GPS receiving circuit, and reference numerals 32 and 33 denote connection terminals. FIG. 4 shows a circuit configuration of the antenna 1.
In the above, the GPS receiving circuit 31 receives the GPS signal 42 from the GPS antenna element 21, calculates the position data, and outputs it as, for example, a digital position data signal 43. Numeral 34 is a communication signal transmitting / receiving circuit in the communication circuit 30, which receives the intermediate frequency transmission signal 44, converts it to a transmission signal of the transmission frequency, amplifies it, outputs the transmission signal 45, and receives the reception signal 48, and Amplification and frequency conversion to an intermediate frequency reception signal are performed, and the intermediate frequency reception signal 49 is output. A signal separation circuit 35 in the communication circuit 30 separates the intermediate frequency signals 44 and 49 from the control signal 50.
Reference numeral 36 denotes a control circuit in the communication circuit 30, which receives the control signal 50, provides a transmission / reception switching signal 51 to the transmission / reception circuit 34 according to the control signal, and, according to the control signal, communicates with the communication antenna element as is generally known. A rotation control signal 52 for constantly directing 18 toward the geostationary communication satellite
To the motor 24. Next, the antenna 1 having the above-described configuration for a moving object
A description will be given of the mounting of. A moving object such as a truck 54 as shown in FIG.
In the above, the place 55 where the antenna 1 is to be installed is selected as a place where there is no obstruction to the radio waves around, and the antenna 1 is mounted there. When the place 55 is in a horizontal state, the mounting portion 3 of the antenna 1 may be mounted as it is. However, in a case of an inclined state, a mounting table 56 as shown is used so that the antenna 1 can be mounted in a horizontal state. Then, the mounting table 56 is fixed to the place 55 with the bolt 57 and the antenna 1 is mounted on the mounting table 56 with the bolt 58.
Fix with. One end of each of the transmission lines 59 and 60 is connected to the connection terminals 32 and 33, and the other end of each of the transmission lines is connected to the indoor unit in the vehicle of the truck 54. The reception of GPS radio waves and the transmission and reception of communication radio waves using the antenna 1 mounted as described above will be described. As shown in FIG. 6, GPs coming from many GPS satellites 40
The S radio wave 41 is received by the GPS antenna element 21.
As a result, the position data signal 43 is transmitted from the antenna 1 to the transmission line.
Sent to the indoor unit through 60. When the intermediate frequency transmission signal 44 is supplied from the indoor unit to the antenna 1 through the transmission line 59, it is transmitted as a transmission signal 45 to the communication antenna element 18, and the communication antenna element 18 transmits the transmission radio wave 46. It is launched toward the geostationary communication satellite 61 through the region 12 on the peripheral side wall of the radome 10. The transmission radio wave 46 reaches a ground fixed station (base station) 62 via the satellite 61. Radio waves emitted from the ground fixed station 62 toward the satellite 61 are received by the antenna 1 via the satellite 61
When it arrives as 47, the received radio wave 47 is received by the communication antenna element 18 through the area 12 of the radome 10 and becomes a received signal 48. As a result, the intermediate frequency reception signal 49 is transmitted from the antenna 1 to the indoor unit through the transmission line 59. In this specification, the transmission radio wave 46 and the reception radio wave 47 are used.
Are collectively referred to as communication radio waves. In the antenna 1, even if the track 54 changes direction, the communication antenna element 18 is rotated by the rotation device 23 based on the control signal from the indoor unit, and the communication antenna element 18 is always in the geostationary communication satellite 61. Is maintained. Therefore, transmission and reception of communication radio waves through the satellite 61 can be performed properly. As described above, according to the present invention, the above problems can be solved, the antenna can be easily mounted, the mounting place can be easily selected, and the space for the mounting place is small. There is an effect that the reception of the upper GPS radio wave and the transmission and reception of the communication radio wave can be properly performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view. FIG. 2 is a longitudinal sectional view. FIG. 3 is a sectional view taken along line III-III. FIG. 4 is a block circuit diagram. FIG. 5 is a perspective view showing an attached state to a truck. FIG. 6 is an operation system diagram. FIG. 7 is a perspective view showing a conventional antenna mounted on a track. [Description of Signs] 2 Base frame 10 Radome 18 Communication antenna element 21 GPS antenna element

Claims (1)

(57) [Claims 1] A radome having a space for accommodating an antenna element is placed on a base frame having a mounting portion to a moving body, and is surrounded by the radome. In the space, a communication antenna element for transmitting and receiving a communication radio wave toward a communication satellite is rotatably arranged in a state facing the peripheral side wall of the radome. A mobile satellite communication antenna, comprising a GPS antenna element for receiving GPS radio waves arriving from a large number of GPS satellites at a top portion avoiding a side wall region.