CONICAL BEAM ANTENNA FOR CIRCULAR POLARIZED WAVE

摘要

PURPOSE:To get rid of deterioration of the radiation characteristics of a strip antenna, and to obtain a small-sized and durable antenna, by constituting so that a feeder to a radiation element of a loop antenna is lowered vertically onto the surface of a lower strip antenna from the radiation element. CONSTITUTION:A radiation element 1 is placed like a ring to a loop antenna whose circumferential length is about 4 wavelength, a microstrip antenna is formed by a small disk 2 whose circumferential length is slightly smaller than 4 wavelength, a large disk 3 which is much larger than said disk, and a spacer 4, and a feeder 6 is provided. Subsequently, a feeder 5 of the loop antenna is lowered vertically onto the large disk 3 without touching the lower small disk 2 from the radiation element 1, is made to pass through it, and is concentrated in one spot. In this way, a radiation wave 11 from the strip antenna is hardly screened by the feeder 5 and the radiation element 1 in the main beam direction theta0, deterioration of the radiation characteristics of the strip antenna is not caused, and also a small-sized and durable antenna is obtained.