3-D Printing Conformal K-Band Lens Antenna for a Smart Parking Space Detection System

With the widespread use of vehicles, finding an empty parking space in a parking lot has become a problem that most drivers encounter daily, particularly in urban environments. In this article, a 3-D printing high-gain dielectric lens <inline-formula> <tex-math notation="LaTeX">$K$ </tex-math></inline-formula>-band antenna is designed for a smart parking radar system that performs dual-mode detection by using a magnetic sensor to improve the accuracy of parking space detection. The proposed antenna uses a wideband high-efficiency electromagnetic structure (WHEMS) as the primary feed antenna. The primary antenna is etched on a substrate and can be easily integrated with a radio frequency (RF) circuit. The WHEMS antenna has a wide bandwidth that is not influenced by instability in the substrate permittivity. Benefiting from low-cost, fast prototyping 3-D printing technology, a conformal flat semiclosed perforation dielectric lens is designed to achieve a high gain; this lens avoids the measurement unreliability caused by large penetration losses in the <inline-formula> <tex-math notation="LaTeX">$K$ </tex-math></inline-formula>-band. The <inline-formula> <tex-math notation="LaTeX">$K$ </tex-math></inline-formula>-band radar operates at 24–24.25 GHz, with a measured gain of 18.4 dBi. Measurements obtained from the developed system reveal that the proposed high-gain, low-cost, lightweight, durable, integrated design approach is well-suited for a <inline-formula> <tex-math notation="LaTeX">$K$ </tex-math></inline-formula>-band radar smart parking system.