| 摘要 |
PURPOSE:To obtain an inexpensive polarizer with small size and high separation by connecting an input/output port waveguide to an electric field face of a cross type waveguide and allowing the input/output port waveguide to excite a vertically polarized wave and a horizontally polarized wave at each of two frequency bands. CONSTITUTION:A waveguide through which two frequency bands f1, f2(f1<f2) are propagated is the cross type waveguide 22'. Then ports 11, 12 excite respectively a V polarized wave f1V and an H polarized wave f1H and ports 13, 14 excite both the polarized waves at the higher frequency band f2 respectively. Filters F1, F2 pass the f1V, f1H and block f2V, f2H and filters F3, F4 have inverse characteristic as that of the F1, F2. The V polarized wave and the H polarized wave are propagated only in regions I and IIrespectively. Since the electromagnetic wave distribution disturbed tentatively at the coupling hole part is not taken place at the center part of the waveguide 22' through the construction above, so long as the regions I and II are orthogonal, the propagating mode taking the region II as the propagating region is not produced. Thus, even if an independent coupling hole is provided to four waveguide electric field, no crossed polarized component is produced by the electromagnetic distribution disturbed by the coupling hole and the polarized wave is not tilted. |
