Abstract: Disclosed is an internal antenna that provides impedance matching for multiple bands. The antenna includes an impedance matching part, which in turn includes a first conductive element electrically coupled to a feeding point and a second conductive element electrically coupled to a ground, and at least one radiator electrically coupled to the first conductive element, where the first conductive element and the second conductive element of the impedance matching part are separated by a particular distance to perform coupling matching and are electrically coupled at a pre-designated position. Certain aspects of the present invention can be utilized to provide wide band characteristics in designing for multi-band applications, even for high-frequency bands.

Abstract: A patch antenna synchronously generating a circularly polarized wave and a linearly polarized wave comprises a first radiator radiating a circularly polarized wave with respect to an antenna signal, a first substrate provided at a part or the whole of the rear surface of the first radiator, a second radiator provided at a part or the whole of the rear surface of the first substrate and radiating a linearly polarized wave with respect to the antenna signal, and a second substrate provided at a part or the whole of the rear surface of the second radiator.

Abstract: Disclosed is a wide-band internal antenna that uses a slow-wave structure. The antenna includes an impedance matching/power feed part, which includes a first conductive element that extends from a power feed line and a second conductive element that is separated by a particular distance from the first conductive element and is electrically connected with a ground, and at least one radiator extending from the impedance matching/power feed part. Here, the first conductive element and the second conductive element of the impedance matching/power feed part form a slow-wave structure. By applying a slow-wave structure to coupling matching, the antenna provides the advantage of resolving the problem of narrow band characteristics found in inverted-F antennas while maintaining a low profile.

Abstract: The present invention relates to a technology for forming a patch antenna generating both linearly and circularly polarized waves at the same time, so as to reduce a propagation loss during transmission/receiving operations between a circularly polarized antenna and a linearly polarized antenna.

Abstract: An RF cavity filter is disclosed. The disclosed filter includes: a housing having at least one cavity defined; a cover coupled to an upper portion of the housing; at least one resonator contained within the at least one cavity; at least one hole formed in the cover; at least one grounding bolt configured to be inserted into the hole, having a screw thread formed on a part of an outer perimeter, and having a center hole in a center portion; and at least one tuning bolt inserted into the housing through the center hole along a screw thread formed on an inner perimeter of the center hole, where the grounding bolt has a flange part formed on a lower portion that is in contact with the tuning bolt and a lower portion of the cover.

Abstract: Disclosed is a method for manufacturing an RF device. The method comprises the steps of (a) forming a metal sheet where interior structure of the RF device is formed; (b) attaching a plastic material housing to the formed metal sheet; and (c) performing silver plating on the RF device on which the plastic material housing is attached.

Abstract: A frequency tunable filter comprises a housing having a plurality of walls therein defining a plurality of cavities; a cover mounted on the housing; a plurality of resonators contained in the cavities; at least one sliding member located between the cover and the resonators; and a plurality of metal tuning elements attached to a lower part of the sliding member, wherein frequency tuning is performed by sliding of the sliding member.

Abstract: Disclosed is a phase shifter having a power dividing function. The phase shifter includes: an input port for receiving a radio frequency (RF) signal; a power dividing unit for dividing the RF signal into a first divided signal of which phase is to be varied and a second divided signal having a fixed phase value; a first output port for outputting the second divided signal having the fixed phase value; a phase shift unit for dividing the first divided signal into a third divided signal and a fourth divided signal wherein the third divided signal and the fourth divided signal move in opposite directions; a phase delay unit for shifting phase of the third divided signal and the fourth divided signal based on a difference in a path length of the third divided signal and the fourth divided signal, to thereby generate phase-shifted signals; and at least two second output ports connected to the phase delay unit, for outputting the phase-shifted signals.

Abstract: A built-in antenna having a center feed structure for wireless terminal. The antenna includes: a feeding means for providing an electromagnetic signal; and a radiating means for radiating the electromagnetic signal, wherein the feeding means is located on a point ranging from a midpoint of the antenna. The antenna radiates a nondirectional signal and can be embedded in a wireless terminal.

Abstract: Provided is a multi-band antenna using a whip having independent power feeding in a wireless telecommunication terminal. The multi-band antenna of a wireless telecommunication terminal includes a first feed point for feeding an electric signal provided from an electric signal provider; a second feed point for feeding an electric signal provided from the electric signal provider; a plurality of radiators for radiating the electric signal fed from the first feed point into an electromagnetic wave signal; and a whip radiator for radiating the electric signal fed from the second feed point into an electromagnetic wave signal in order to increase the radiant efficiency of the electromagnetic wave signal radiated from a plurality of radiator and extend a bandwidth.

Abstract: Provided is a multi-band antenna using a whip having independent power feeding in a wireless telecommunication terminal. The multi-band antenna of a wireless telecommunication terminal includes a first feed point for feeding an electric signal provided from an electric signal provider; a second feed point for feeding an electric signal provided from the electric signal provider; a plurality of radiators for radiating the electric signal fed from the first feed point into an electromagnetic wave signal; and a whip radiator for radiating the electric signal fed from the second feed point into an electromagnetic wave signal in order to increase the radiant efficiency of the electromagnetic wave signal radiated from a plurality of radiator and extend a bandwidth.

Abstract: A built-in antenna having a center feed structure for wireless terminal. The antenna includes: a feeding means for providing an electromagnetic signal; and a radiating means for radiating the electromagnetic signal, wherein the feeding means is located on a point ranging from a midpoint of the antenna. The antenna radiates a nondirectional signal and can be embedded in a wireless terminal.

Abstract: A repeater and method for automatically setting output signal level of the repeater is disclosed. The repeater includes: a voltage detection unit for measuring a voltage of signal amplified by a plurality of the amplifiers; a digital variable resist unit for providing a reference voltage value Vref; a comparison unit for comparing the detected voltage Vdec from the voltage detection unit and the reference voltage value Vref from the digital variable resist unit; and a control unit for setting output signal level of the repeater by controlling the digital variable resistor unit to generate the reference voltage Vref to be identical to the detected voltage Vdec and controlling an output of repeater based on the comparison result from the comparison unit after setting the output signal level of the repeater.

Abstract: A switchable combiner and apparatus for providing intergrated combiner unit, which can reduce problem due to frequent substitution of unit. The apparatus for providing intergrated combiner unit includes the means of; a) dividing input signal according to basic type, redundancy type or power division/coupling type; b) switching the transmitted signal to power amplifier; c) switching the transmitted signal to the means of combining; and d) combining the transmitted signal according to basic type, redundancy type or power division/coupling type.

Abstract: A wideband built-in antenna in a portable terminal includes a ground plate electrically connected to a ground of the portable terminal, a radiation element for radiating radio waves, wherein the radiation element is formed into a zigzag shape having a predetermined thickness and width in parallel with the ground plate, a feeding point for feeding signals into the radiation element, a feeding probe connecting the feeding point to the radiation element and a holder for fixing the antenna to the portable terminal.

Abstract: Disclosed is a wideband directional antenna in a wireless communication service, comprising at least one radiation element, wherein the radiation element includes at least one loop, wherein one feeding point of the loop is connected to feeder and the other feeding point is connected to a ground distributor.

Abstract: A helical antenna having a simple structure and being made of cheap conductor to reduce the manufacturing cost, and a manufacturing method thereof. A helical antenna comprises a dielectric core, a conductive strip, a feeding conductor, and an external circuit. The dielectric core has a substantially cylindrical shape with an outer circumferential surface on which a spiral groove is formed. The conductive strip is deposited on the groove of the dielectric core. The feeding conductor is placed under the dielectric core and provides an electrical connection between the conductive strip and an external circuit. The antenna cover encloses the dielectric core and the feeding conductor.

Abstract: The bandpass filter according to the present invention includes a housing having a plurality of cavities, wherein said plurality of cavities are isolated from each other by partitions and wherein each said partition have a coupling window; input/output connectors formed at both ends of said housing so as to pass output signals from a transmitter; coupling loops connected to said input/output connectors so as to excite an applied signal power and to combine resonance modes; dielectric resonators installed in said cavities of said housing so as to resonate a signal power transmitted from said coupling loop to the desired frequency band, said dielectric resonators including: a first resonator group formed in both said cavities which are adjacent to said coupling loops; and a second resonator group formed in said cavities which are positioned between both said cavities which are adjacent to said coupling loops, wherein said resonators of said second resonator group are stepped resonators; a plurality of frequency

Abstract: Dual band retractable antenna system with capacitive coupling includes a helical antenna for operating at stand-by mode, the helical having ¼ wavelength; a whip, which penetrates the helical, for operating at busy mode, the whip having ¼ wavelength; a stopper for catching the whip when the antenna is extended out; a sleeve mounted to one end of the helical, for operating as a feed point when the whip is extended out; a capacitive coupling arrangement placed between the helical and the sleeve, for capacitively coupling the helical to the sleeve; and a matching circuit connected between the sleeve and the antenna system, so that the antenna system operates for both frequency bands.