| 摘要 |
PURPOSE:To increase the degree of freedom of each antenna insulation position and improve mean transmission and reception gain by combining plural antennas through a hybrid circuit, and making total directivity in a horizontal plane uniform. CONSTITUTION:Dipole antennas 21 and 22 are installed in the rooms of an automobile 1 near the front windshield and the rear windshield respectively, and transmit and receive signals of the antennas 21 and 22 are mixed by the hybrid circuit 3 and connected to a transmitter 5 and receivers 41 and 42. The circuit 3 has plural feeder terminals; the terminal 61 is connected to the output of the transmitter 5 and the input of the receiver 41, and the terminal 62 is connected to the input of the receiver 42. The outputs of the receivers 41 and 42 are selected optionally by a switch 7 and outputted to a diversity output terminal 8. Therefore, the individual diversity of the antennas 21 and 22 is disordered by the car body, etc., but the composite total horizontal plane directivity of the circuit 3 is made uniform in every direction. |
