Wide-Band and Low-Profile LTCC Conformal Antenna Array With Mixed Feeding Network

As we know, the thickness mainly affects the yield of low-temperature co-fired ceramics (LTCC) device. There is a high risk of cracking for the thick structure in manufacture process especially for the curved one. In this paper, double-layer artificial magnetic conductors (AMCs), mixed feeding network and built-in wide-band laminated waveguide (LWG) with rectangular waveguide (RWG) transition are specially analyzed and designed. These structures all have low-profile characteristics. Thus, they are suitable for conformal LTCC process. The double-layer AMCs are presented to enhance the bandwidth and the gain of a Ka-band patch element. The thin mixed network consisting of microstrip line (MSL) and LWG is used to replace the thick multistage LWG network. An improved LWG-RWG transition integrated in LWG layer is designed to possess wider bandwidth. At last, the low-profile conformal 16x16 antenna array is designed, manufactured and tested. The measured results demonstrate that the low-profile conformal 16x16 antenna array has a good and stable performance with an enhanced impendence bandwidth of 12.17% and a high gain up to 26.9dB.