Mahmoud Ouda

On-Chip Implantable Antennas for Wireless Power and Data Transfer in a Glaucoma-Monitoring SoC

For the first time, separate transmit and receive on-chip antennas have been designed in an eye environment for implantable intraocular pressure monitoring application. The miniaturized antennas fit on a 1.4-mm 3 CMOS (0.18 μm) chip with the rest of the circuitry. A 5.2-GHz novel inductive-fed and loaded receive monopole antenna is used for wirelessly powering the chip and is conjugately matched to the rectifier in the energy-harvesting and storage unit. The 2.4-GHz transmit antenna is an octagonal loop that also acts as the inductor of the voltage control oscillator resonant tank. To emulate the eye environment in measurements, a custom test setup is developed that comprises Plexiglass cavities filled with saline solution. A transition, employing a balun, is also designed, which transforms the differential impedance of on-chip antennas immersed in saline solution to a 50-Ω single-ended microstrip line. The antennas on a lossy Si substrate and eye environment provide sufficient gain to establish wireless communication with an external reader placed a few centimeters away from the eye.

Digital on-chip phase noise measurement

In this paper, we propose an All-Digital On-Chip Phase Noise Measurement Technique. This Technique can be integrated as part of a built-in self-test (BIST) scheme for phase-locked loop (PLL)-based clock synthesizers. The proposed technique based on an all digital ΣΔ-frequency discriminator (ΣΔFD). Unlike all previously reported techniques, our proposed technique is implemented using digital-only circuits. This makes it easily integrated and scaled down for high-density microprocessor applications with modern sub 100nm technology nodes

A 5.2GHz, 0.5mW RF powered wireless sensor with dual on-chip antennas for implantable intraocular pressure monitoring

For the first time a single chip implantable wireless sensor system for Intraocular Pressure Monitoring (IOPM) is presented. This system-on-chip (SoC) is battery-free and harvests energy from incoming RF signals. The chip is self-contained and does not require external components or bond wires to function. This 1.4mm3 SoC has separate 2.4GHz-transmit and 5.2GHz-receive antennas, an energy harvesting module, a temperature sensor, a 7-bit TIQ Flash ADC, a 4-bit RFID, a power management and control unit, and a VCO transmitter. The chip is fabricated in a standard 6-metal 0.18μm CMOS process and is designed to work with a post-processed MEMS pressure sensor. It consumes 513μW of peak power and when implanted inside the eye, it is designed to communicate with an external reader using on-off keying (OOK).

Wide-Range Adaptive RF-to-DC Power Converter for UHF RFIDs

A wide-range, differential, cross-coupled rectifier is proposed with an extended dynamic range of input RF power that enables wireless powering from varying distances. The proposed architecture mitigates the reverse-leakage problem in conventional, cross-coupled rectifiers without degrading sensitivity. A prototype is designed for UHF RFID applications, and is implemented using 0.18 μm CMOS technology. On-chip measurements demonstrate a sensitivity of -18 dBm for 1 V output over a 100 kΩ load and a peak RF-to-DC power conversion efficiency of 65%. A conventional, fully cross-coupled rectifier is fabricated alongside for comparison and the proposed rectifier shows more than 2× increase in dynamic range and a 25% boosting in output voltage than the conventional rectifier.

Implantable Intraocular Pressure Monitoring systems: Design considerations

Design considerations and limitations of implantable Intraocular Pressure Monitoring (IOPM) systems are presented in this paper. Detailed comparison with the state of the art is performed to highlight the benefits and challenges of the proposed design. The system-on-chip, presented here, is battery free and harvests energy from incoming RF signals. This low-cost design, in standard CMOS process, does not require any external components or bond wires to function. This paper provides useful insights to the designers of implantable wireless sensors in terms of design choices and associated tradeoffs.

A highly sensitive RF-to-DC power converter with an extended dynamic range

This paper proposes a highly sensitive RF-to-DC power converter with an extended dynamic range that is designed to operate at the medical band 433 MHz and simulated using 0.18 μm CMOS technology. Compared to the conventional fully cross-coupled rectifier, the proposed design offers 3.2× the dynamic range. It is also highly sensitive and requires −18 dBm of input power to produce a 1 V-output voltage when operating with a 100 kΩ load. Furthermore, the proposed design offers an open circuit sensitivity of −23.4 dBm and a peak power conversion efficiency of 67%.

Digital enhancement of frequency synthesizers

In this paper, we propose an All-Digital On-Chip Phase Noise Measurement Technique. This Technique can be integrated as part of a built-in self-test (BIST) scheme for phase-locked loop (PLL)-based clock synthesizers. The proposed technique based on an all digital ΣΔ-frequency discriminator. Unlike all previously reported techniques, our proposed technique is implemented using digital-only circuits and can report digital numbers corresponding to the close in phase noise level of the PLL to a digital BIST controller. This makes it easily integrated and scaled down for high-density microprocessor applications with modern sub 100nm technology nodes.