Mobile antenna system
First Claim
1. A mobile antenna system comprising:
- a turn detecting section for detecting the state of turn in a mobile;
an antenna controllable with respect to its beam direction;
a receiving section for taking a signal proportional to the strength of a radiowave received by said antenna; and
a beam direction control section for changing the beam direction according to the turning angle of the mobile detected by said turn detecting section and also the strength of the radiowave received by said receiving section;
a satellite direction searching section for controlling the beam direction of said antenna over a broad range to obtain a higher strength in said received radiowave and to find the satellite direction; and
a control selecting section for selecting one of a plurality of control modes depending on said strength of received radiowave and said state of turn;
said control modes selected by said control selecting section being at least three types;
(a) an on-nonturning control selected when it is judged that the mobile is moving straight and adapted to change the beam direction of the antenna slightly so as to detect the direction of the highest strength of received radiowave;
(b) an on-turning control selected when it is judged that the mobile is turning and adapted to change the beam direction of the antenna depending on the state of turn and also to select the direction of the highest strength of received radiowave; and
(c) an on-blocking control selected when said received radiowave is blocked and is adapted to change the beam direction of the antenna depending on the state of turning.
1 Assignment
0 Petitions
Accused Products
Abstract
In mobile communications, it is required that the beam direction is maintained to track the desired direction as the mobile is moving. For such a purpose, the mobile includes an angular rate sensor mounted therein which detects the state of turn in the mobile and to control the beam direction of the antenna in accordance with the state of turn as well as the strength of radiowave received by a receiver in the mobile. Antenna elements are in the form of microstrip antenna and are arranged in plane on the same dielectric substrate. Feeding and drive circuit layers for controlling the transmission and reception at the antenna elements are stacked into a single layered unit. This enables the antenna system to be formed into a low-profile structure. The dielectric substrate of the microstrip antenna element is formed by stacking a plurality of dielectric substrate different in dielectric constant from one another. It is thus intended that the band width of the antenna is increased and that the mutual coupling between the antenna elements is reduced to prevent the gain of the antenna from being lowered. Furthermore, the position of feed points in the antenna element are rotated against each adjacent antenna element. This can improve the axial ratio in the array antenna over a wide band width.
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Citations
12 Claims
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1. A mobile antenna system comprising:
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a turn detecting section for detecting the state of turn in a mobile; an antenna controllable with respect to its beam direction; a receiving section for taking a signal proportional to the strength of a radiowave received by said antenna; and a beam direction control section for changing the beam direction according to the turning angle of the mobile detected by said turn detecting section and also the strength of the radiowave received by said receiving section; a satellite direction searching section for controlling the beam direction of said antenna over a broad range to obtain a higher strength in said received radiowave and to find the satellite direction; and a control selecting section for selecting one of a plurality of control modes depending on said strength of received radiowave and said state of turn; said control modes selected by said control selecting section being at least three types; (a) an on-nonturning control selected when it is judged that the mobile is moving straight and adapted to change the beam direction of the antenna slightly so as to detect the direction of the highest strength of received radiowave; (b) an on-turning control selected when it is judged that the mobile is turning and adapted to change the beam direction of the antenna depending on the state of turn and also to select the direction of the highest strength of received radiowave; and (c) an on-blocking control selected when said received radiowave is blocked and is adapted to change the beam direction of the antenna depending on the state of turning. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification