Comparison of array antenna designs for 77GHz radar Applications

Abstract

In this paper, two types of microstrip array antenna for radars operating at 77 GHz are presented. The first type of array antenna is 10 × 4 elements rectangular patch array antenna with overall size of 20.43 mm×7.83 mm. Unit element of this antenna type is a rectangular patch. Series-fed column of 10 unit elements are arranged into 10 × 4 arrays by implementing simple power divider structure. The second type of antenna is 12 × 4 elements leaf array antenna with overall size of 16.72 mm×10.75 mm. Unit element of the second antenna type is a rectangular patch that is inclined 45 • from the microstrip line axis. Twelve patches are arranged on both sides of the microstrip line and are connected directly at their corners. One additional patch at the end of the structure acts as a matching element. Array consisting of 12 × 4 unit elements are created by implementing simple power divider structure. Both types of antenna are combined with different types of waveguide-to-microstrip transition consist of two metal layers printed on a single dielectric substrate. The waveguide-to-microstrip transitions are fed by WR10 standard waveguide. The performances of both antennas are verified via simulations and measurements. The rectangular patch array antenna has 19.8 dB gain and 20 • × 10 • beam width at 77 GHz, while the leaf array antenna has 19.6 dB gain and 19 • × 11.6 • beam width at 77 GHz. Both types of antenna can be further developed as a reference for designing antenna for radar systems operating at higher frequencies, such as 94 GHz.

Development of Rogers RT/Duroid 5880 Substrate-Based MIMO Antenna Array for Automotive Radar Applications

“…e side lobe level between -4 and -12.4 dB is obtained at the dual bands of 24 GHz and 77 GHz. But the same parameter was achieved between -9 and -11 dB using 10-20 elements in [7]. Henceforth, our proposed model that is able to provide much better performance with just two elements can be chosen as the best alternative to the conventional series-fed patch antennas.…”

“…But the design at 77 GHz witnessed only very few developments. In [7], the antenna for radar application at 77 GHz by means of an array of series-fed rectangular patches in the order of 10 × 4 and 12 × 4 was proposed with an overall array size of 20.43 × 7.8 mm 2 and 16.72 × 10.75 mm 2 , respectively. Ushemadzoro Chipeng et al [8] have simulated the radar system design using a single column of five-element series-fed patch antenna as TX antenna and four columns of five-element serial-fed array as RX antenna with the gain of 15 dB and 20 dB, respectively.…”

Design and Optimization for 77 GHz Series-Fed Patch Array Antenna Based on Genetic Algorithm

“…At present, there are many kinds of design schemes for the patch array antennas used in 77 GHz automotive radars. The 77 GHz microstrip patch antenna arrays in [9,10] are designed to traditional series-fed type. The same patches are arranged in a string separated by an electrical wavelength.…”