On-chip monopole antennas using pre-deformed cantilevers

In this paper, we propose a novel monopole antenna made of an out-of-plane pre-deformed cantilever beam caused by high residual stress. The proposed antenna has the following advantages: 1) radiating element is perpendicular to the plane of the wafer and is isolated from the lossy substrate by a ground plane. Thus, it can achieve high efficiency even with low-resistivity silicon substrates; 2) the fabrication process is fully compatible with conventional integrated circuit (IC) process which ensures low fabrication cost; 3) relatively wide bandwidth can be obtained from a monopole structure (more than 16%); 4) it can be fabricated on flexible substrates due to the very small anchor of the cantilever beam. Experimental results of the proposed antenna geometry and its full-wave numerically calculated radiation characteristics are presented in this paper.