Compact Patch Antenna Array for 60 GHz Millimeter-Wave Broadband Applications

In this study, a wide-band compact patch antenna array is developed for 60 GHz band applications. The antenna array consists of eight identical elements. Each element is a simple microstrip-fed rectangular radiating patch printed on the top side of a Rogers 5880 substrate. A rectangular ground plane is printed on the bottom side. To adjust the impedance matching for broadband operation, a complete circular-shaped slot and a part of circular-shaped slot are etched off the ground plane and the patch, respectively. A technique to feed the array elements unequally is employed for design a more compact antenna structure with improved gain and impedance bandwidth. An electromagnetic band-gap (EBG) reflector below the array structure is employed to decrease backward radiation and improve front-to-back (F/B) radiation ratio. The antenna array with the EBG reflector has a compact size with overall dimensions of 17.5 x 22 x 1.262 mm(3). It achieves operation bandwidth from 56.5 to 65.2 GHz (|S-11| <= - 10 dB), which covers the 60 GHz unlicensed band (57-64 GHz). The gain variation is from 12 to 16 dBi over the entire operating band. These features make the proposed antenna array system a suitable candidate for industrial, scientific and medical (ISM) broadband applications at 60 GHz band.