In general, the disclosure describes an RFID tag designed such that the tag is both covert and not easily blocked from the interrogation signal by the hand or other body part of a person. In particular, the RFID tag is designed to have a long, narrow aspect that allows placement of the tag in locations on or in a book that are inconspicuous to the casual observer while extending beyond a hand of a person holding the book by the spine on or near a geometry centerline. The RFID tag includes a dipole segment and a loop segment coupled to the dipole segment. The loop segment of the modified dipole antenna provides the antenna with larger signal strength than conventional dipole antennas. Moreover, the conductive loop segment also provides improved impedance matching capabilities to allow the modified dipole antenna to match the impedance of an integrated circuit (IC) chip of the RFID tag.

Rfid tag with a modified dipole antenna

Microelectromechanical (MEMS) devices and associated methods are disclosed. Piezoelectric MEMS transducers (PMUTs) suitable for integration with complementary metal oxide semiconductor (CMOS) integrated circuit (IC), as well as PMUT arrays having high fill factor for fingerprint sensing, are described.

Integrated piezoelectric microelectromechanical ultrasound transducer (pmut) on integrated circuit (ic) for fingerprint sensing

A fingerprint sensing apparatus includes a fingerprint sensor system and a control system capable of receiving fingerprint sensor data from the fingerprint sensor system. The control system may determine, according to the fingerprint sensor data, whether an object is positioned proximate a portion of the fingerprint sensor system. If the control system determines that an object is positioned proximate the portion of the fingerprint sensor system, the control system may determine whether the object is a finger or a non-finger object. The control system may determine whether the fingerprint sensor data includes fingerprint image information of at least an image quality threshold.

Layered filtering for biometric sensors

A fingerprint sensing apparatus may include a fingerprint sensor system and a control system. The fingerprint sensor system may include an ultrasonic sensor array. The control system may be capable of receiving fingerprint sensor data from the fingerprint sensor system and of determining whether an object is positioned proximate a portion of the fingerprint sensor system. The control system may be capable of determining an acoustic impedance of at least a portion of an object that is positioned proximate the fingerprint sensor system. The control system may be capable of determining whether the acoustic impedance is within an acoustic impedance range corresponding to that of skin and of determining, based at least in part on the acoustic impedance, whether the object is a finger.

Finger/non-finger determination for biometric sensors

Wet-chemical methods involving the use of water-soluble hydrolytically stable metal-ion chelate precursors and the use of a nonmetal-ion-containing strong base can be used in a coprecipitation procedure for the preparation of ceramic powders. Examples of the precipitants used include tetraalkylammonium hydroxides. A composition-modified barium titanate is one of the ceramic powders that can be produced. Certain metal-ion chelates can be prepared from 2-hydroxypropanoic acid and ammonium hydroxide.

Method of preparing ceramic powders using chelate precursors

Provided herein is a method of making an integrated circuit device using copper metallization on 1-3 PZT composite. The method includes providing an overlay of electroplated immersion of gold (Au) to cover copper metal traces, the overlay preventing oxidation on 1 :3 PZT composite with material. Also included is the formation of immersion Au nickel electrodes on the 1-3 PZT composite to achieve pad metallization for external connections.

Touch fingerprint sensor using 1-3 piezo composites and acoustic impediography principle

Disclosed are three-dimensional dielectric structures on high surface area electrodes and fabrication methods. Exemplary structures comprise a copper foil substrate, trench electrodes or high surface area porous electrode structures formed on the substrate, a insulating thin film formed on the surface and laminating the foil on a organic substrate. A variety of materials may be used to make the films including perovksite ceramics such as barium titanate, strontium titanate, barium strontium titanate (BST), lead zirconate titanate (PZT); other intermediate dielectric constant films such as zinc oxide, aluminum nitride, silicon nitride; typical paraelectrics such as tantalum oxide, alumina, and titania. The films may be fabricated using sol-gel, hydrothermal synthesis, anodization or vapor deposition techniques.

Integrating three-dimensional high capacitance density structures

Disclosed are composite RF devices having low temperature coefficient of permittivity (TCP) and methods for fabricating same. The RF devices comprise first and second conductive electrodes with a composite dielectric material disposed there between that comprises a polymer material having positive or negative TCP and one or more ceramic filler materials having corresponding negative or positive temperature coefficients of permittivity. The composite dielectric material may also comprise a blend of positive and negative TCP ceramic filler materials. The composite dielectric material may also have a bimodal distribution of positive and negative TCP filler materials to vary the packing density of the dielectric material. Various devices may be fabricated including thin and thick film capacitors and antennas, which may be formed on or within an organic layer, silicon material, ceramic material, ceramic composite material or insulating material.

Organic based dielectric materials and methods for minaturized RF components, and low temperature coefficient of permittivity composite devices having tailored filler materials

Nano-structured interconnect formation and a reworkable bonding process using solder films Large area fabrication of nano-structured interconnects is demonstrated at a very fine pitch This technology can be used for pushing the limits of current flip chip bonding in terms of pitch, number of I/Os, superior combination of electrical and mechanical properties as well as reworkability Sol-gel and electroless processes were developed to demonstrate film bonding interfaces between metallic pads and nano interconnects Solution-derived nano-solder technology is an attractive low-cost method for several applications such as MEMS hermetic packaging, compliant interconnect bonding and bump-less nano-interconnects

Lead-free bonding systems

Disclosed are organic-compatible thin film processing techniques with reactive (such as Ti) layers for embedding capacitors into substrates. Hydrothermal synthesis allows direct deposition of high-k films with capacitance density of about 1 μF/cm 2 on organic substrates. This is done by reactively growing a high-k film from Ti foil/Ti-coated copper foil/Ti precursor-coated organic substrate in an alkaline barium ion bath. Alternatives may be used to address multiple coatings, low temperature baking, low temperature pyrolysis with oxygen plasma, etc. Sol-gel and RF-sputtering assisted by a reaction with the intermediate layer and a foil transfer process may be used to integrate perovskite thin films with a capacitance in the range of 1-5 μF/cm 2 . Thermal oxidation of titanium foil/Ti-coated copper foil/Ti-coated organic substrate with a copper conductive layer is also a reactively grown high-k film process for integrating capacitance of hundreds of nF with or without using a foil transfer process.

Isaac Robin Abothu

Papers

Touch fingerprint sensor using 1-3 piezo composites and acoustic impediography principle

Integrating three-dimensional high capacitance density structures

Organic based dielectric materials and methods for minaturized RF components, and low temperature coefficient of permittivity composite devices having tailored filler materials

Lead-free bonding systems

Reactively formed integrated capacitors on organic substrates and fabrication methods