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1205-L09-10

CONFORMABLE PATCH ANTENNA ARRAY FOR ENERGY HARVESTING Akshat C. Patel2, Miral P. Vaghela2, Hassan Bajwa2 and Prabir K. Patra1,3 1 Department of Mechanical Engineering, University of Bridgeport, Bridgeport, Connecticut, USA 06604; 2 Department of Electrical Engineering, University of Bridgeport, Bridgeport, Connecticut, USA 06604. 3 Department of Biomedical Engineering, University of Bridgeport, Bridgeport, Connecticut USA 06604 ABSTRACT Carbon nanotube (CNT) has emerged as potential candidate for replacement of conventional metal patch in antenna application. The principal objective of our research is to develop nanostructured flexible patch antenna array for multi- frequency operation in industrial, scientific and medical (ISM) band. Patch antenna design using single walled CNT (SWNT) on flexible cotton sheets has been simulated with cotton as a substrate and SWNT as conductive patch and ground plane. Due to high conformability and conductivity of SWNT all antenna parameters like VSWR, return loss, gain and radiation pattern obtained using FEKO EMSS software meet design criteria. Our simulated antenna design shows a return loss less than -10 dB and VSWR less than 2 at 2.06 GHz, 2.38 GHz and 2.49 GHz. We have also simulated a versatile and conformable antenna design where the whole geometry is rolled up like patch array on cylindrical surface. Conformability to curved surfaces and integration with the structure brings about a unique antenna design. An inset fed square patch array is also proposed for RF energy harvesting operating in the 2.45 GHz ISM band that can harvest and store energy from the surrounding environment. Simulation result shows that dc voltage of 0.215 V can be achieved at -6 dbm received energy level at 2.45 GHz IEEE 802.11b band. This would correspond to potential working distance of 10m. INTRODUCTION Carbon nanotubes were observed in 1991 in the carbon soot of graphite electrodes during an arc discharge, by using a current of 100 amps [1]. However, the first macroscopic production of carbon nanotubes was made in 1992 [2]. The explosive growth of the carbon nanotube (CNT) research in energy harvesting technology [3,4] have accentuated the need for miniaturized, high-efficiency conformal antennas that can operate over a wide range of frequencies, while they can be integrated in wearable and lightweight configurations [5]. Extensive research has been carried out in recent years to fabricate antenna with SWNT and conductive polymer inks instead of metallic conductors [6]. Fig. 1 shows few example of successfully fabricated polymer based antenna by inkjet printing of conductive polymer-SWNT inks using different fabric as a substrate like cotton, fleece, nylon etc [7, 8] Using carbon nanotube instead of tradition metal, we can actually create conformal patch array that will lead to much more efficient ways of converting electromagnetic radiation to electricity [9]. Several efforts have been made in this area to scavenge power effectively using flexible textile antenna. Nano Composite exhi