| 摘要 |
PROBLEM TO BE SOLVED: To provide a small sized antenna system convenient for coupling with an active element in which inter-coupling loss between transmission reception antenna elements is small. SOLUTION: An antenna structure 10 includes plural transmission linear elements 22a-22d and plural reception linear elements 24a-24d arranged in parallel. Each of the transmission linear elements 22a-22d is arranged at an interval and one reception linear element is arranged between adjacent transmission linear elements, each width of the transmission linear elements and reception linear elements is changed periodically in the lengthwise direction and then the impedance is periodically changed. Furthermore, the narrowest portion of each transmission linear element is arranged closely to the most width portion of the reception linear element arranged closely to the transmission linear element and the coupling between the elements is minimized. Transmission amplifiers 16a, 16b and reception amplifiers 30a, 30b are arranged at both ends of an antenna shaft main body 36 so as to be close to the corresponding antenna element respectively to reduce the loss furthermore. |
