PURPOSE: To improve the isolation between a transmission antenna and a reception antenna by providing a conductor rod between the transmission antenna and the reception antenna and bending the tip of the conductor toward the transmission antenna.
CONSTITUTION: A rod shaped choke 5 made of a conductor such as aluminum is provided between a transmission antenna 3 and a reception antenna 4. The choke 5 is arranged at a position apart by a prescribed distance from a center line 6 of the antenna 3. The shape of the choke 5 is a shape folded to the center line 6 and the tip is formed in parallel with an upper face of the transmission antenna 3. In order to improve more the isolation between the antennas 3, 4, a choke 5' is provided also to a position symmetrical to the choke 5 with respect to the center line 6. The quantity of a radio wave directly made incident in the antenna 4 from the antenna 3 is reduced by providing the chokes 5, 5' to improve the isolation between the antennas 3 and 4.
MIZUGAKI HISAYOSHI
KANEKO KAZUO
KADO SEIJI
| JP63081406B |