Loic Marnat

New Movable Plate for Efficient Millimeter Wave Vertical on-Chip Antenna

A new movable plate concept is presented in this paper to realize mm-wave vertical on-chip antennas through MEMS based post-processing steps in a CMOS compatible process. By virtue of its vertical position, the antenna is isolated from the lossy Si substrate and hence performs with a better efficiency as compared to the horizontal position. In addition, the movable plate concept enables polarization diversity by providing both horizontal and vertical polarizations on the same chip. Through a first iteration fractal bowtie antenna design, dual band (60 and 77 GHz) operation is demonstrated in both horizontal and vertical positions without any change in dimensions or use of switches for two different mediums (Si and air). To support the movable plate concept, the transmission line and antenna are designed on a flexible polyamide, where the former has been optimized to operate in the bent position. The design is highly suitable for compact, low cost and efficient SoC solutions.

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.

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).

Liquid Crystal Polymer (LCP) based antenna for flexible system on package (SoP) applications

The design, fabrication and measurement of a bowtie antenna on a flexible Liquid Crystal Polymer (LCP) substrate is reported in this paper. The antenna is fed by a balun transition which helps improve the gain up to 5.1 dB. The antenna performance is analyzed for both planar and curved substrates. The comparison between simulation and measurements shows a good agreement. This structure can either be used to sense the bending of the substrate or use the bending to tilt the beam.

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.

Comparison of Synthesis Strategies for a Dual-Polarized Reflectarray

This paper presents and compares four optimization strategies for printed reflectarrays. They are applied to synthesize a dual-polarized reflectarray using two kinds of slot-loaded patches. They provide objective criteria to deal with the numerous geometrical parameters available to tune the phase. The study relies on the comparative measurements of four different prototypes for the same 22𝜆0×22𝜆0 reflectarray (with 𝜆0 the wavelength at 𝑓0=14.25 GHz).