Radar Range Enhancement Using Reflectarray Technique.

The reflectarray antenna is typically used in wireless communication systems to extend the communication range. In this work, we adapted a reflectarray antenna to inexpensive radar transceivers, thereby increasing the range of the radar without modifying the electronic circuits. The reflectarray antenna is designed for battery-operated portable devices, therefore the dimension (30 x 20 cm) and weight (~1/4 kg) were minimized as much as possible. The detailed design process of the reflectarray antenna and performance improvements, including the range increase of a human target, are presented. The feeders of the reflectarray radar system tested in this study are off-the-shelf, low-profile 24 GHz traffic monitoring radar transceivers with the gain of the antenna at around 10.71 dBi. The demonstrated reflectarray antenna has a gain of 21.18 dB, resulting in a combined total gain of 31.89 dBi. The performance of the radar system with the designed reflectarray antenna was evaluated using frequency modulated continuous wave (FMCW) and frequency shift keying (FSK) modulations. The range and speed measurements of a human target using both techniques revealed that the reflectarray antenna does not degrade the accuracy of the speed while increasing the range three-fold. Compared with conventional antenna gain boost methods, the reflectarray provides a simple, lightweight, inexpensive and flexible option for increasing the range of the radars. [ABSTRACT FROM AUTHOR]