2×1 Tapered Recessed Ground Microstrip Patch Antenna Array at 60 GHz

This paper presents a two element tapered recessed ground microstrip patch antenna array at 60 GHz. The use of tapered recessed ground overcomes the fabrication challenges of narrow slots of inset-feed technique, especially on high indexed substrates. Prototypes of 60 GHz 2 × 1 conventional (A
₁
) and tapered recessed ground (A
₂
) microstrip patch antenna array are fabricated on 0.127 mm thick alumina substrate (ε
_r
= 9.8) as a proof of concept. The measured results indicate a -10-dB impedance bandwidth of 2.16 % (A
₁
), and 14 % (A
₂
) with return loss better than 15 dB at 60 GHz. The measured gain of antenna A2 (7.05 dBi) is more by 1.2 dB, than antenna A1 (5.85 dBi) at 60 GHz.