| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an inexpensive Yagi antenna substrate which can be easily formed by preparing plural via holes of different diameters on a substrate and making these via holes function as the reflectors or waveguides of a Yagi antenna. SOLUTION: Three via holes 1-3 are prepared on a printed circuit board 4 and function as a radiator, a reflector and a waveguide respectively. The inner diameter surfaces of holes 2 and 3 have the cylindrical shapes and serve as the conductor surfaces. Furthermore, the holes 1-3 are almost linear and aligned almost equidistantly. Then the diameter of the reflector is larger than that of the waveguide with the same length secured between them. In other words, the holes 1-3 of different diameters are formed on the board 4 of almost the even thickness so that the reflector, the waveguide and also the radiator can be properly used. Thus, it is possible to obtain an inexpensive Yagi antenna substrate that can be easily formed and is suitable to the mass production.</p> |
