Title:
MOBILE OBJECT SATELLITE COMMUNICATION TERMINAL EQUIPMENT
Document Type and Number:
Japanese Patent JP3125744
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To automatically select an antenna directed to a direction without an obstacle and to perform efficient communication by providing the plural antennas for transmission of different directivity in a top direction and a horizontal plane direction and switching the antenna to be used based on the reflected waves of radiated radio waves by the antenna in use at present.
SOLUTION: When an antenna switch 3 is connected to the antenna 5 directed in the horizontal direction, when the obstacle is present around in the horizontal direction, the return loss of the antenna 5 is deteriorated and a part of the amplification power of a power amplifier 1 is returned. The return power makes a control circuit 9 switch the antenna switch 3 to the antenna 4 directed in a vertical direction through a directional coupler 2, a detection diode 6 and an operational amplifier 8. Inversely, at the time of using the antenna 4, when the obstacle is present in the vertical direction, the control circuit 9 automatically switches the antenna switch 3 to the antenna 5 similarly. Thus, communication is efficiently performed in the case of performing use in a place surrounded by buildings, inside a pocket or indoors, etc.
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Inventors:
Akihiro Kirisawa
Application Number:
JP11304998A
Publication Date:
January 22, 2001
Filing Date:
April 23, 1998
Export Citation:
Assignee:
NEC
International Classes:
H04B7/26; H01Q1/36; H01Q3/24; H01Q11/08; H04B7/06; H04B7/155; (IPC1-7): H04B7/155; H04B7/26
Domestic Patent References:
| JP9223994A | ||||
| JP6164232A |
Attorney, Agent or Firm:
Hiroo Suzuki