Gain and Efficiency Enhanced Flip-Up Antennas for 3D Integrated Wireless Sensor Applications

In this paper, a flip-up antenna concept for 3D integrated wireless sensor applications is presented. This technique utilizes a flip-up configuration to improve antenna gain and radiation efficiency which usually are the key issues for the integrated antennas in wireless sensor systems. A balanced and an unbalanced flip-up antennas operating at 2.4 GHz ISM band are numerically and experimentally studied. To verify the enhancement of the gain and efficiency of those proposed antennas, similar conventional balanced and unbalanced antennas are fabricated and characterized for comparison. It is shown that the gain and radiation efficiency approximately increase 5 dB and 40 % by using the flip-up configurations. Compared to the conventional ones, the 6 dB return loss bandwidth of the flip-up balanced and unbalanced antennas decrease from 69 to 25 and from 67 to 46 MHz respectively. Good agreements between the simulations and measurements of all the presented antennas are achieved.