公开(公告)号：JPS56115005A

公开(公告)日：1981-09-10

申请号：JP1807180

申请日：1980-02-15

Applicant: SONY CORP

Inventor： TADA MASAHIRO ,  ICHIKAWA KOUICHI ,  FUKUSHIMA MITSUO ,  NAKAMICHI TAKAYA ,  OOUCHI KOUJI ,  ISHIGAKI YOSHIO

IPC: H01Q3/24 ,  H01Q7/00

Abstract: PURPOSE:To ensure an easy change-over in a wide band for both the direction and the directional pattern, by providing a plural number of feeding points to the main and auxiliary loops formed on several different faces and then switching these feeding points. CONSTITUTION:The main antenna structure that forms a main loop is composed of the conductors A1-D1; and the conductors E-H plus A2-D2 from a plural number of auxiliary antenna structures. These auxiliary antenna structures are connected directly or indirectly to the conductor M to form a plural number of auxiliary loops. The feeding points (a)-(d) are provided to these conductors A1-D1, and one of these feeding points is selected to be connected to the output or input terminal. Other feeding points are short-circuited, opened or connected to the impedance element Z. For instance, the feeding point (a) is selected, and the incoming electric wave is put vertically onto the plane formed by the connecting points P1, P4, P8 and P5 as shown by the arrow N. Thus the current I1 flows to the closed loop which is shown by a broken line in the figure. For the distribution of this current, the peak part of the current I1 exists at the center of the conductors A1 and C1, and the area where the current I1 becomes zero exists at the center of the conductors B2 and D2 respectively.

公开(公告)号：JPS5711547A

公开(公告)日：1982-01-21

申请号：JP8567480

申请日：1980-06-24

Applicant: SONY CORP

Inventor： OSADA YASUO ,  TADA MASAHIRO ,  ICHIKAWA KOUICHI ,  NAKAMICHI TAKAYA ,  OOUCHI KOUJI

IPC: H04B7/10 ,  H04B7/08

Abstract: PURPOSE:To prevent deterioration in picture quality without delay in response of AGC, by making the switching of a diversity receiving antenna through the video signal after video detection. CONSTITUTION:A signal from variable directivity antennas 1a, 1b installed in the interval of lambda/4 is applied to turns 3a, 3b, IF amplifiers 4a, 4b and video detection circuits 5a, 5b. A detected output via video amplifiers 13a, 13b is given to a switch circuit 14. Further, the detected output is applied to a switching signal forming circuit 100 to obtain the switching signal of the switch circuit 14 and the switch circut 14 is switched to a given level or more through this switching signal. Further, if both the detected output levels are less than the specified value, a signal changing the directivity of antenna is produced from the forming circuit 100. Thus, the antenna switching can be made without delay of response such as AGC, allowing to prevent the deterioration of video quality.