Double-frequency transmitting monopole antenna for portable high-frequency ground wave radar

Abstract

The invention discloses a double-frequency transmitting monopole antenna for portable high-frequency ground wave radar. The double-frequency transmitting monopole antenna consists of an antenna upper section, a wave trap, an antenna lower section, a feed base and a ground network, wherein a conductor on the antenna upper section is h1 high and a conductor on the antenna lower section is h2 high. When the wavelength lambda 2 corresponding to the radar signal frequency f2 meets a formula of h2=k lambda2 / 4, the wave trap makes resonance oscillation so as to equivalently isolate the antenna upper section and ensure that the antenna upper section becomes a typical quarter-wave vertical monopole on the ground and has a major lobe of a radiation directional diagram along the ground surface. When the radar signal frequency is far lower than f2, the wave trap is in dissonance, so that the whole height of the antenna is equivalently increased to h3, and therefore the whole antenna forms a quarter-wave monopole with resonance being in lower frequency f1, meets a formula of (h1+h2+h3)=k Lambda 1 / 4 and has a major lobe of a radiation directional diagram along the ground surface as well. The double-frequency transmitting monopole antenna disclosed by the invention can work on two frequency bands respectively taking f1 and f2 as central frequencies conveniently, and both the two frequency bands have major lobes of directional diagrams along the ground surface. Besides, the adopted feed base realizes favorable waterproof structure design.

Description

technical field [0001] The invention relates to the technical field of radar detection, in particular to a dual-frequency transmitting monopole antenna for portable high-frequency ground wave radar. Background technique [0002] The portable high-frequency sea state radar used to detect ocean surface currents, waves and wind fields uses a compact monopole as the transmitting antenna and a compact monopole cross-ring as the receiving antenna, so it does not need to open up a wide antenna field, which greatly improves the The construction and maintenance costs of the radar station are reduced, and the seaside application is very convenient and flexible. Therefore, this portable radar accounts for 90% of the total number of high-frequency ground wave radars in operation in the world today. [0003] At present, in order to enhance the function of the portable high-frequency ground wave radar and further improve its performance, a multi-frequency working method has been proposed....

AI Technical Summary

Problems solved by technology

Although the antenna operates at frequency f 1 , the main lobe of the radiation pattern is along the ground, but when working at frequency f 2 , the main lobe elevation angle of the radiation pattern of the antenna is very large (elevation angle α=50°), but the radiation intensity along the ground is very small, and decreases with the increase of antenna thickness, so it is not suitable for ground wave radar

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