Design and Measurement of 3D Flexible Antenna Diversity for Ambient RF Energy Scavenging in Indoor Scenarios

Abstract

Ambient radiofrequency (RF) energy scavenging has been recently addressed with a wide range of studies to provide alternative powering for low-power applications. However, due to the low power level of the ambient electromagnetic field, the efficiency of the latter systems is still below expectations. Multipath in the environment may be considered and antenna diversity is then a solution for quasi-omnidirectional RF reception to reach a higher probability of receiving energy in a realistic situation. A 3D flexible antenna diversity, which can be integrated into the rectangular packaging, is proposed in order to take advantage of system packaging form. The angle and polarization diversity antenna was designed on flexible substrate in order to achieve the flexibility and low-cost. This design overcomes the low performance of the substrate while maintaining a compact, high isolation, and good radiation efficiency of the antenna. An indoor experimental setup was carried out to compare different rectenna configurations. The measurement results validate the principle and demonstrate the performance of the 3D flexible diversity system. The probability measurements were carried out under precise conditions in indoor scenarios and the results in comparison with statistic models confirmed the performance of the system in such low power conditions. INDEX TERMS Antenna diversity, indoor propagation, flexible structures.

Reconfigurable Nonlinear Circuit for Wireless Power Harvesting and Backscattering

“…Its key SPICE parameters are listed below in Table I. This diode has been widely used in lowpower rectifier design [17]. Also, it has been reported that SMS7630 is a suitable candidate for a fully passive harmonic transponder design to reduce conversion loss [14].…”

Compact Collinear Quasi-Yagi Antenna Array for Wireless Energy Harvesting

“…However, one directional antenna or antenna array cannot overcome itself blind areas. For complementing the coverage and losing less energy in the blind spot, multiple patch or Yagi antennas situated on a cubic [26], [27] or cylindrical structure [22], or placed in a circle [28], [29] or back-to-back patterns [25] were designed and demonstrated. One patch antenna was deployed on one side of the cubic in [27].…”

“…One patch antenna was deployed on one side of the cubic in [27]. For enhancing the harvesting performance, the patch was replaced by the Yagi on the cubic structure [26]. The gain was further elevated to over 8 dBi by using a suspended large patch antenna [25] or a patch antenna array [22].…”

Influence of mesh geometries on the design of transparent antennas at 2.45 GHz

“…Indeed, printing processes allow the production of antennas on larger flexible substrates like polyethylene terephthalate (PET), paper by an additive process limiting the amount of product used and the environmental impact. The development of flexible antenna for energy scavenging by 3D printing in [1] allows tending new markets. The design of antenna using flexible substratepaper-for energy harvesting at 1800MHz describe in [2] shows compact antenna with high gain.…”

“…An innovative technique for the development of optically transparent antennas is the meshing method like describe in [1]. The antennas develop by meshing method have lower performance in terms of realized gain or radiation than their no-mesh homologue.…”