Chapters authored
Innovative Techniques for 60-GHz On-Chip Antennas on CMOS Substrate
The 60-GHz band has a 7-GHz of bandwidth enabling high data rate wireless communication. Also, it has a short wavelength allowing for passive devices integration into a chip, that is, fully integrated system-on-chip (SOC) is possible. This chapter features the design, implementation, and measurements of 60-GHz on-chip antennas (OCAs) on complementary-metal-oxide-semiconductor (CMOS) technology. OCAs are the primary barrier for the SOC solution due to their limited performance. This degraded performance comes from the low resistivity and the high permittivity of the CMOS substrate. We present here two innovative techniques to improve the CMOS OCAs’ performance. The first method utilizes artificial magnetic conductors to shield the OCA electromagnetically from the CMOS substrate. The second methodology employs the PN-junction properties to create a high resistivity layer. Both approaches target the mitigation of the losses of the CMOS substrate; hence, the radiation performance characteristics of the OCAs are enhanced.
Part of the book: Microwave Systems and Applications
WPT, Recent Techniques for Improving System Efficiency
Wireless power transfer (WPT) technologies have received much more attention during the last decade due to their effectiveness in wireless charging for a wide range of electronic devices. To transmit power between two points without a physical link, conventional WPT systems use two coils, one coil is a transmitter (Tx) and the other is a receiver (Rx) which generates an induced current from the received power. Two main factors control the performance of the WPT schemes, power transfer efficiency (PTE) and transmission range. Power transfer efficiency refers to how much power received by the rechargeable device compared to the power transmitted from the transmitter; while transmission range indicates the longest distance between transmitter and receiver at which the receiver can receive power within the acceptable range of power transfer efficiency. Several studies were carried out to improve these two parameters. Many techniques are used for WPT such as inductive coupling, magnetic resonance coupling, and strongly coupled systems. Recently, metamaterial structures are also proposed for further transfer efficiency enhancement. Metamaterials work as an electromagnetic lensing structure that focuses the evanescent transmitted power into receiver direction. Transmitting & Receiving antenna systems may be used for sending power in certain radiation direction. Optimizing the transmitter antenna and receiver antenna characteristics increase the efficiency for WPT systems. This chapter will present a survey on different wireless power transmission schemes.
Part of the book: Wireless Power Transfer