| 摘要 |
PROBLEM TO BE SOLVED: To prevent rapid changes in a transmission path characteristic and to keep a state to enable an automatic equalizing function to follow-up by executing control to slowly change transmission/reception levels at the time of the changeover of a transmission/reception antenna. SOLUTION: A changeover control part 3 at a transmission side 10 recognizes a positional relation between the transmission side 10 and a reception side 11 by information from a detecting means, discriminates a transmission antenna 4-1 or 4-2 to face a reception antenna 5 and outputs a changeover control signal. A continuous variable control part 13 generates a signal with which a signal level is gradually changed with time in accordance with a control signal, while a continuous variable route changeover part 12 executes an operation where a transmitting signal to be impressed on an input terminal I is sorted to output terminals 0a and 0b in accordance with a control signal level, so as to permit the respective levels to be inversely proportional. Thus, the antenna at the transmission side 10 is changed gradually so that the characteristic change of a transmission path in terms of time, generated by antenna changeover is made slow to allow automatic equalizing processing to follow-up. |
