Air-Coupled GPR Antenna Layout for Direct Wave Suppression
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Solution Overview
Problem
Existing air-coupled ground penetrating radar systems are limited by the magnitude of direct wave signals that interfere with imaging performance, reducing detection quality.
Innovation Solution
The system employs a directional horn antenna as the transmitter and a vertically oriented loop antenna at the receiver, with orthogonal feeding directions, and uses impedance loading to minimize ringing and spurious radiation, while being housed in metal or non-metal boxes with absorbing materials to enhance detection performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional parallel antenna arrangement is used, then the system structure is simple, but the direct wave signal magnitude is high which limits imaging performance
Solution Approach 1:
The patent applies asymmetry by changing the relative orientation of the transmitting and receiving antennas from parallel to orthogonal. The transmitting antenna is oriented in the x-direction while the receiving antenna is oriented in the y-direction, creating an asymmetric configuration that reduces direct wave coupling between antennas while maintaining detection capability.
Solution Approach 2:
The patent transitions from a two-dimensional parallel antenna arrangement to a three-dimensional orthogonal configuration. By positioning the receiving antenna vertically (in the y-direction) rather than parallel to the transmitting antenna (x-direction), the system utilizes the third spatial dimension to reduce direct wave interference while preserving signal detection.
2Measurement precision
If the receiving antenna is placed parallel to the transmitting antenna, then the antenna structure is simple, but the direct wave signal magnitude is high which interferes with reflected wave detection
Solution Approach 1:
The patent applies asymmetry by changing the relative orientation of the transmitting and receiving antennas from parallel to orthogonal. The transmitting antenna is oriented in the x-direction while the receiving antenna is oriented in the y-direction, creating an asymmetric configuration that reduces direct wave coupling between antennas while maintaining detection capability.
Solution Approach 2:
The patent converts the harmful effect of direct wave interference into a beneficial configuration by using orthogonal antenna orientations. The direct wave, which would normally couple strongly between parallel antennas, is now minimized due to the orthogonal arrangement, allowing the reflected wave signals to be detected with higher precision.
3Measurement precision
If horn antennas are used as air-coupled GPR antennas, then the antenna has high directivity suitable for shallow depth detection, but direct wave signals are still received which limits dynamic range
Solution Approach 1:
The patent applies asymmetry by changing the relative orientation of the transmitting and receiving antennas from parallel to orthogonal. The transmitting antenna is oriented in the x-direction while the receiving antenna is oriented in the y-direction, creating an asymmetric configuration that reduces direct wave coupling between antennas while maintaining detection capability.
Solution Approach 2:
The patent changes the orientation parameter of the receiving antenna from parallel to the transmitting antenna to orthogonal. This parameter change fundamentally alters the coupling characteristics between antennas, reducing direct wave reception while preserving the high directivity benefit of horn antennas for shallow depth detection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration significantly reduces direct wave reception, improving radar detection performance by enhancing the ratio of reflected wave signal strength, thereby improving data quality and detection capabilities.
Implementation Method 1
a transmitting antenna 100 and a receiving antenna 200. The transmitting antenna 100 transmits a signal towards the ground and the receiving antenna 200 receives a signal
Implementation Method 2
the receiving antenna 200 receives a signal from an electromagnetic wave reflected from a discontinuous surface of the ground or an object buried in the ground
Implementation Method 3
uses impedance loading to minimize ringing and spurious radiation
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention relates to an air-coupled type bistatic ground penetrating radar (GPR) antenna and, more specifically, to an air-coupled type ground penetrating radar (GPR) antenna which reduces reception of a direct wave, which is a factor limiting imaging performance of a system when being received at a receiving side of the GPR antenna, by placing a loop antenna at a receiver point so as to be vertical to an antenna plane with respect to a polarization direction of a transmitting antenna and configuring a feeding direction to be orthogonal to a feeding direction of a transmitter and the ground surface. The air-coupled type GPR antenna, which is spaced apart from the ground, comprises: the transmitting antenna directed towards the ground and penetrating a radio wave into the ground; and a receiving antenna receiving a radio wave, which is radiated from the transmitting antenna and then reflected from the ground, and fed in a direction perpendicular to the ground surface and the feeding direction of the transmitting antenna. The transmitting antenna uses an antenna, such as a horn antenna, having directivity and the receiving antenna uses a loop antenna in which a physical plane of the antenna is positioned to be perpendicular to the ground surface with respect to the polarization direction, thereby resulting in the effect of improving radar detection performance of an air-coupled type GPR system.