This small business innovation research Phase I project explores novel wireless antenna technologies based on metamaterial volumetric folded antennas structures. The approach is to compress, twist, and fragment metal strips or discs in a multi-layer structure to form self-tuned, bandwidth optimized, and miniaturized antennas. The design methodology of engineering the coupled-line common and differential modes simultaneously presents many opportunities for radio-frequency and microwave components in wireless technology. The new approach of reducing dramatically antenna resonant length and stored electric and magnetic energy, at the same time, while increasing many times the radiated power in an area-constrained multi-layer platform is unique and opens up many possibilities of useful integrated antenna structures. The research methodology is to fold metamaterial slow-wave wires. Those folded wires spread out into multiple layers use effectively the antenna volume in integrated circuits and enhance many times the radiation resistance. The proposed ideas combine the theory of metamaterial slow-wave coupled lines, folded integrated antennas, and volumetric wires, aiming for miniaturization as well as the bandwidth and efficiency optimization and offering a competing edge over the existing products in iphone, global position systems, wireless local access network, and global system mobile devices.
The broader impact/commercial potential of this project is on wireless communication technologies and applications that have been under tremendous growth in this new century. Present wireless technology is geared toward the consolidation of multiple networks into one communication system. There is an ever increasing demand for electronics systems that are extremely compact in size and capable of multiple functionalities. As the radio and digital chip size becomes smaller, radio-frequency passive components, particularly antennas remain salient features and the bottleneck for device miniaturization. This project offers a unique solution for dramatic size reduction without degrading antenna performance. The proposed concept of metamaterial volumetric folded antennas to replace conventional planar wire antennas will have broader impact on radio-frequency communication systems. The new idea would have an immediate market demand on iphones. The product could expand into other wireless networks, such as global satellite navigation, radio-frequency identification, wireless local access network, Bluetooth, and paging systems. The integration of the proposed technology into the wireless products for personal communications has significant market potential.
This small business innovation research Phase I project develops novel antennas based on metamaterial volumetric folded antennas structures. The approach is to compress, twist, and fragment metal strips or discs in a multi-layer structure to form self-tuned, bandwidth optimized, and miniaturized antennas. The engineering methodology is to design the coupled-line common and differential modes simultaneously. The new approach of reducing dramatically antenna resonant length and stored electric and magnetic energy, at the same time, while increasing many times the radiated power in an area-constrained multi-layer platform is unique and opens up many possibilities of useful integrated antenna structures. The research methodology is to fold metamaterial slow-wave wires. Those folded wires spread out into multiple layers use effectively the antenna volume in integrated circuits and enhance many times the radiation resistance. The proposed ideas combine the theory of metamaterial slow-wave coupled lines, folded integrated antennas, and volumetric wires, aiming for miniaturization as well as the bandwidth and efficiency optimization and offering a competing edge over the existing products in iphone, global position systems, wireless local access network, and global system mobile devices. The investigation found that the folded antenna model widely used for over many decades introduces significant errors in impedance, Q factor, and bandwidth when the folded dipole loop is wide. Models were proposed to characterize analytically both the inductive coupling coefficient and the antenna Q factor. It was found that a symmetric folded dipole could have a much lower Q factor (larger bandwidth) than a dipole (its unfolded version). One could have 50% in Q reduction and almost 100% increase in bandwidth. The analysis performed in this project validates significant bandwidth enhancement of a folded dipole over its unfolded version. The analysis is further extended to the asymmetric case. It was found that increasing the arm radius ratio (higher impedance transformation) would increase BW. An example of Q reduction by more than 50% or more than 100% increase in BW was demonstrated. An electrically small slow-wave antenna that benefits from the proposed BW enhancement techniques was prototyped. Normally, reducing antenna length also reduces the radiation resistance in electrically small antennas. This project further addressed the issue of stored energy reduction such that the Q factor can be reduced by 2 times. The way to accomplish it is to space the folded dipole wide enough (arm distance) so that the two arms in a folded dipole are more or less decoupled. It was found that using two identical meandered dipoles and folding them together with proper spacing results in half of the Q factor. In this project, the bandwidth enhancement method also applied to folded monopoles, where half of the dipole is replaced by a ground plane. Measured data confirmed the validity of the Q reduction folding scheme for a monopole. The broader impact/commercial potential of this project is on wireless communication technologies and applications that have been under tremendous growth in this new century. Present wireless technology is geared toward the consolidation of multiple networks into one communication system. There is an ever increasing demand for electronics systems that are extremely compact in size and capable of multiple functionalities. As the radio and digital chip size becomes smaller, radio-frequency passive components, particularly antennas remain salient features and the bottleneck for device miniaturization. This project offers a unique solution for dramatic size reduction without degrading antenna performance. The proposed concept of metamaterial volumetric folded antennas to replace conventional planar wire antennas will have broader impact on RF communication systems. The new idea would have an immediate market demand on iphones. The product could expand into other wireless networks, such as global satellite navigation, radio-frequency identification, wireless local access network, Bluetooth, and paging systems.
