Development of a High-Gain Lens Antenna for 24-GHz Forward-Looking Collision Warning Radar
|關鍵字:||前視防撞雷達;Forward-looking collision-avoidance radar|
In this thesis, a 24GHz forward-looking collision warning antenna operating at 24.025GHz~24.225GHz has been developed. In order to separate transmitted and received signal at reality application, we generally use two kinds of structures. First one is double antenna structure but the drawback is using double area. Another type is single antenna structure, which uses the quadrature hybrid to separate transmitting and receiving signals. The cost is extra 6dB loss. When feed antenna is located lens focal point radiating energy through lens, the main lobe is located at axis. We introduce a new antenna structure putting transmitting and receiving feed antenna at focal point two sides. The main lobes of the transmitting and receiving signal diverge from axis, but the intersectional region of the transmitting and receiving signals is still locate at axis. In practical application, RF active and passive components are surrounded by metal shield. We treat the effect when antenna surrounded by metal wall. We can enhance the isolation between transmitting and receiving port when we properly design the metal wall. We discuss about different space among transmitting and receiving antenna impact on radiation pattern and the isolation between transmitting and receiving port. In the end, we measure the radar cross section of vehicle at different angles. Then we calculate the radar detection region by the radar equation.
|Appears in Collections:||Thesis|
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