A Portable High Frequency Ground Wave Radar Receiving Antenna

Abstract

The invention discloses a portable high-frequency ground wave radar receiving antenna. The antenna comprises a monopole whip antenna, a shielding box, a crossed loop antenna and a pedestal; a circuitboard is built in the shielding box, and a matching circuit, an amplification circuit and a filtering circuit in ordered electrical connection are integrated in the circuit board; the crossed loop antenna comprises a two loop antennae placed in crossed form, each loop antenna comprises a top horizontal oscillator, a bottom horizontal oscillator and two spiral arms; the spiral arms both are in a vertical state, the spiral arms are used for connecting the top horizontal oscillator and the bottom horizontal oscillator in the corresponding loop antenna; each spiral arm comprises a plastic supportrod and several turns of spiral loops coiled on the support rod. With the antenna provided by the invention, input impedance of the loop antenna can be improved, matching difficulty is reduced, and meanwhile, mismatching loss is reduced.

Description

Technical field [0001] The invention relates to the technical field of ground wave radar, in particular to a portable high frequency ground wave radar receiving antenna. Background technique [0002] As a dual-purpose over-the-horizon radar for both military and civilian use, high-frequency ground wave radar is different from ordinary radars in the military. It is not affected by the curvature of the earth and can detect ships and helicopters out of sight. For civilian use, it has important application value in detecting ocean currents, waves and wind, disaster warning and disaster relief. [0003] Since the conventional ground wave radar uses phased array antennas, it occupies hundreds to thousands of meters in the sea, which requires too much space. The emergence of portable antennas has solved this problem. However, portable antennas still have the following problems that need to be resolved: [0004] 1. The portable antenna is an electrically small antenna, the antenna size is ...

AI Technical Summary

Problems solved by technology

[0004] 1. The portable antenna is an electrically small antenna, and the size of the antenna is much smaller than the resonance wavelength of the ground wave radar, which is 30 meters, so the efficiency is very low

[0005] 2. The input impedance of the simple loop antenna is very small, while the input impedance of the amplifier circuit and the signal processing module at the back end is relatively large. The impedances of the two with a large difference in impedance do not match when transmitting high-frequency electromagnetic waves, and the superposition produces standing waves and the standing wave ratio is too high. large, causing the received signal to reflect back to the antenna, making the radar completely inoperable

[0006] 3. The efficiency of the portable antenna is already very low, and the matching method of the existing loading resistor will further reduce the performance of the antenna

[0007] 4. Some ground wave receiving antennas use ferrite materials to achieve miniaturization. This material must be closely connected with the outer radiator of the antenna to function

In addition, in practical engineering applications, as the magnetic permeability of ferrite and other parameters change, the performance of the antenna will be affected, which will cause the instability of the entire ground wave radar.

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