Korea Institute of Science and Technology

Hyun Jai Kim

Seok Jin Yoon

Ji Won Choi

Chong Yun Kang

Piotr Vasiljev

Hyung Jin Jung

Hyun Phill Ko

Sung Hun Sim

Dae Yong Jeong

Dong Kyun Lee

Hyeung Kwon Choi

Kucheiko Sergei

The present invention relates to a piezoelectric linear motor that can make relatively low abrasion and accurate linear movement since stationary AC voltages are applied to two piezoelectric elements with a phase difference. The present invention provides a piezoelectric linear motor, comprising: a piezoelectric substrate having a first piezoelectric element and a second piezoelectric element, wherein AC voltages are applied to the first and second piezoelectric elements with a phase difference; a metallic elastic body having first and second elastic bodies coupled to the piezoelectric elements and a central protrusion protruded at the central portion connecting the first and second elastic bodies, wherein the central protrusion oscillates elliptically during an application of the voltage; and a mover brought into contact with the central protrusion of the metallic elastic body for a linear movement, and wherein the movement of the mover is orthogonal to the central protrusion.

Piezo electric linear motor

A piezoelectric linear motor for amplifying the change in at least one dimension of a piezoelectric material is disclosed. A shaft is connected axial-movably to a piezoelectric actuator. The actuator includes a piezoelectric ceramic that expands or contracts in response to an applied voltage. The expansion or contraction of the piezoelectric ceramic is amplified by converting the displacement due to expansion/contraction into a greater displacement of a top plate to which the shaft is coupled. The greater displacement is, for instance, by causing the expansion/contraction of the piezoelectric ceramic into a convex or concave bending of a complex of which the piezoelectric ceramic is a part. In a preferred embodiment the base plate is attached to the piezoelectric ceramic, a slanted plate conically extending from the base plate, and a top plate formed at the center of the slanted plate to form an assembly that changes its curvature to amplify the displacement.

Piezoelectric linear motor with displacement amplifying means

The present invention relates to a linear motor which draws its operating power from ultrasonic vibration above the frequency of 20 kHz which is generated by piezoelectric ceramic. More particularly, the invention relates to a linear piezoelectric ultrasonic motor which linearly operates a slider due to a frictional force generated by applying sinusoidal electric field with a 90 degree phase difference to a pair of piezoelectric ceramic. This causes an elliptical mechanical vibration on a shaking beam which is connected to the piezoelectric ceramic.

Linear piezoelectric ultrasonic motor

A ceramic chip antenna, which has a small size and a broad bandwidth, is provided. The ceramic chip antenna consists of a ceramic body with cuboid shape, a conductor wound helically inside the ceramic body, and signal-feed terminal formed on a surface of the ceramic body. The ceramic chip antenna with a helical conductor patterns formed in a symmetrical dipole shape is provided, which has a high gain value and excellent radiation characteristics. Also, it can be built-in inside a mobile terminal due to its small size. The ceramic chip antenna according to the present invention can have a broad bandwidth that satisfies the variable frequency of the present mobile communication system.

Ceramic chip antenna

The present invention relates to a ring-type piezoelectric ultrasonic motor that is different from the electro-magnetically driven conventional motors and that has applications in robots and automation equipments. More specifically, the present invention relates to a ring-type piezoelectric ultrasonic motor that is driven by a frictional force between rotor and stator, and stator is produced a mechanical displacement by a piezoelectric ceramics applying an alternate electric field with an ultrasonic frequency (above kHz).

Ring-type piezoelectric ultrasonic motor

A monoblock dielectric duplexer comprises resonant holes. Conductive electrodes and couplers are formed on one side of the dielectric block, whose other sides are covered with a conductive material. The conductive electrodes in a transmit-filtering portion are formed in an inter-digitating manner while the conductive electrodes in receive-filtering portion are formed to be of pad-shape. In the duplexer, capacitances of capacitors comprised of the conductive electrodes are easily and accurately set to desired values by determining the number and/or the lengths of fingers that the inter-digitating electrodes have.

Monoblock dielectric duplexer

This invention provides a composition of high frequency dielectric ceramics represented by the following formula:

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Seoul, South Korea

Hyun Jai Kim