Communications: radio wave antennas – Antennas – With means for moving directive antenna for scanning,...
Reexamination Certificate
1999-07-02
2001-07-31
Wong, Don (Department: 2821)
Communications: radio wave antennas
Antennas
With means for moving directive antenna for scanning,...
Reexamination Certificate
active
06268833
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an antenna device for use in a frequency band of a millimeter wave, also relates to a transmitting/receiving apparatus using the antenna device.
2. Description of the Related Art
There has been known an on-vehicle millimeter wave radar for use in a vehicle travelling on a road to measure a distance between this vehicle and another vehicle traveling ahead or behind, so as to measure a relative speed of this vehicle with respect to said another vehicle. Such millimeter wave radar, i.e., a transmitting/receiving apparatus consists of an integrally fabricated module including a millimeter wave oscillator, a circulator, a directional coupler, a mixer and an antenna device, with said transmitting/receiving apparatus being attached on the front or the rear portion of the vehicle.
The antenna device for use in the above millimeter wave radar consists of a primary radiator and a dielectric lens. A transmitting/receiving wave beam is formed by disposing the primary radiator in a focal point position of the dielectric lens.
However, the above conventional millimeter wave radar has at least the following problem which will be discussed in detail in the following. Namely, since the antenna device of the conventional millimeter wave radar has a fixed directivity, some predetermined detections and measurements will fail to be performed in a desired manner because of the restrictions of certain conditions. For instance, when a vehicle is running on a road having a plurality of traffic lanes, if the antenna device merely receives an electromagnetic wave reflected from another vehicle running ahead, it is still not possible to immediately determine whether or not the another vehicle is running along the same traffic lane on which this vehicle is running. Further, if a vehicle is running along a curved section or a waved section on a road, and if another vehicle running ahead of this vehicle along the same traffic lane is deviating from a detectable area, it is impossible to effect a desired detection.
Thus, in order to cope with the above problem, it is allowed to consider rotating an entire frame structure mounting the transmitting/receiving apparatus including the antenna device, so as to deflect the beam of an electromagnetic wave.
However, in use of such a rotatable structure, since an entire frame structure mounting the transmitting/receiving apparatus is required to be rotated, the apparatus as a whole will have to become large. Further, since movable parts of the apparatus have relatively large mass, it will be difficult to enable the beam of electromagnetic wave to scan at a high speed.
SUMMARY OF THE INVENTION
It is an object of the present invention to solve the above discussed problem associated with the above mentioned prior art, by providing an improved antenna device which is easy to be made compact in size and thus suitable for use in a high speed scanning of a beam of an electromagnetic wave. Another object of the present invention is to provide a transmitting/receiving apparatus using the improved antenna device.
According to the present invention, there is provided an antenna device characterized in that a primary radiator and a first transmission line combined with the primary radiator are provided on a movable section, a second transmission line electromagnetically combined with the first transmission line and a dielectric lens with a position of the primary radiator serving as a generally focal point surface are provided on a fixed section, the antenna device further comprising a driving mechanism capable of causing the movable section to be displaced relatively with respect to the fixed section, and control device capable of driving the driving mechanism and rendering the movable section to be displaced in accordance a position designating signal of the movable section. Further, movable section position detecting device for detecting the position of the movable section is provided, the control device is capable of driving the driving mechanism in accordance with a detection result of the movable section position detecting device and the position designating signal of the movable section. With the use of the above constitution, since at least the primary radiator and a first transmission line are provided on the movable section, it is possible to render the movable section compact in size, thereby rendering compact the entire size of the apparatus. Further, by making light the movable section of the apparatus, it is possible to enable the beam to scan at a high speed. In addition, since the above control device is capable of driving the driving mechanism of the movable section, the beam may be deflected in any optional direction by only supplying from outside a position designating signal of the movable section.
Further, according to the present invention, an antenna device as recited in the above is employed, a predetermined position designating signal is supplied to the control device so as to enable a beam, which is decided by a relative relationship between the dielectric lens and the primary radiator, to scan in a predetermined pattern, and to perform predetermined transmission and reception of an electromagnetic wave.
Moreover, according to the present invention, device is provided to store a position of the movable section as a standard position when the axis of the beam of the antenna device is directed in a predetermined direction, the control device is capable of determining the position of the movable section with the standard position serving as a reference.
In addition, according to the present invention, under a condition where the antenna device has been mounted on a mounting equipment such as a vehicle, device is provided for storing the position of the movable section as a standard position when the beam axis is directed in a predetermined direction while being viewed from the mounting equipment, the control device is capable of determining the position of the movable section with the standard position serving as a reference. With the use of the above structure, even if a relative relationship between the primary radiator and the dielectric lens is not uniform due to a possible error in an installing portion of a mounting equipment such as a vehicle or due to an error in an assembling operation, the axis of the beam is allowed to be directed in a predetermined direction without being affected by a fluctuation in the relative relationship.
REFERENCES:
patent: 4257048 (1981-03-01), Yokoi et al.
patent: 4796032 (1989-01-01), Sakurai et al.
patent: 4873526 (1989-10-01), Katsuo
patent: 4887091 (1989-12-01), Yamada
patent: 5751247 (1998-05-01), Nomoto et al.
patent: 5835057 (1998-11-01), Van Heyningen
patent: 5933109 (1999-08-01), Tohya et al.
patent: 6034642 (2000-03-01), Kojima et al.
Kondou Nobuhiro
Nishiyama Taiyo
Tanizaki Toru
Murata Manufacturing Co. Ltd.
Ostrolenk, Faber, Gerb & Soffen, L
Tran Chuc
Wong Don
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