Low Profile Broadband Cavity-Backed Patch Phased Array Antenna for Millimeter Wave Applications

This paper presents a low profile broadband phased array antenna based multilayer low temperature co-fired ceramic (LTCC) technology for system-in-package (SIP) applications operating at millimeter-wave band. The radiating element is fed by a substrate integrated waveguide (SIW) aperture, and U-shaped patch is used to broaden antenna bandwidth, in addition that a SIW cavity is introduced to decrease mutual coupling between adjacent antennas. The total antenna thickness including feeding SIW is 0.9 mm (about 0.1 λ at 35 GHz). Simulated results show that the active VSWR below 2.5 ranges from 32 to 37.6 GHz (16.1%) while scanning up to 60° in E-plane and 45° in H-Plane. Then a 7 × 7 phased array is simulated, the results show that when scanning angle is 60° in E-plane and 45° in H-plane at 35 GHz, peak gain decreases about 3 dB and 1.8 dB, respectively.