| 摘要 |
PURPOSE:To obtain a circularly polarized wave conical beam with simple constitution by feeding power to a microstrip antenna from two points with a phase difference of 90 deg. at the higher harmonic mode of TM210. CONSTITUTION:The antenna of microstrip constitution is formed with a radiation element 9, a feeding circuit 10 with 90 deg. phase difference, a feeding point 16 and termination circuits 14, 15. In exciting the radiation element 9 in the TM210 mode, the radiation electromagnetic field in the direction of the vertical axis is zero and the radiation directivity forms a conical beam. In feeding power to the radiation element 9 from the two points with the electric phase difference of 90 deg., a circularly polarized wave is obtained and the directivity keeps the said conical beam. Moreover, in adopting the higher order mode of the THmno for the exciting mode with the spatial angle of the feeding point selected to (90/m) degrees, the circularly polarized conical beam is obtained even when the power is fed with the electric phase difference of 90 deg.C. |
