Abstract: A Multiple Input Multiple Output (MIMO) antenna system adaptable to an environmental multiplicity is provided. A MIMO antenna system includes a first antenna element, a second antenna element, a receiver for receiving at least one of different polarized signals through the first antenna element, a channel estimator for estimating a channel using a signal received via the receiver and a signal received via the second antenna element, and a correlation comparator for controlling the receiver to receive a specific polarized signal according to a correlation calculated from the estimated channel.

Abstract: A monopole antenna capable of implementing an MIMO system, which includes a ground part formed of plate metal, a monopole antenna element connected to one side of the ground part and formed of strips bent multiple times, an auxiliary antenna element connected to one side of the ground part and disposed adjacent to the monopole antenna element to electrically connect to the monopole antenna element, and a short-circuit part interconnecting the monopole antenna element and the auxiliary antenna element. Accordingly, the monopole antenna element is bent multiple times so that the antenna can become compact in less than half a width compared to the conventional antenna, and when the MIMO system is constructed, the interference between the respective antennas can be reduced so that the array antenna can become compact in size.

Abstract: An antenna having an additional ground, includes a first ground which is formed in one side of a substrate; a plurality of antenna elements which are formed symmetrically with respect to each other and spaced apart from one end of the first ground; and a second ground which is interposed between the plurality of the antenna elements and integrally formed with the first ground. Accordingly, the deterioration of the antenna characteristics can be minimized even after the arrangement of the antenna elements with the ground, and the antenna can be miniaturized and easily fabricated in a two-dimensional structure. Furthermore, the electromagnetic wave interference can be minimized between the antenna elements.

Abstract: A flat-plate MIMO array antenna includes a substrate, a plurality of antenna elements disposed on the substrate, and at least one isolation element interposed between a plurality of antenna elements on the substrate and connected to a ground. Mutual interference between the antenna elements is prevented by the isolation element formed between the antenna elements, thereby preventing the distortion of the radiation pattern. Also, since the isolation element is grounded to the ground surface, the isolation element operates as a parasitic antenna, thereby increasing the output gain.

Abstract: A monopole antenna having a matching function includes a ground; and a radiator having a first radiation part which is connected to a first side of the ground in a strip shape perpendicularly to the ground, and at least one second radiation part which is bent from a first end of the first radiation part at least once.

Abstract: A small broadband monopole antenna having a perpendicular ground plane with an electromagnetically coupled feed is provided. The small broadband monopole antenna may be realized as a small antenna having a size of 0.085?0×0.085?0×0.085?0 by positioning a folded strip line under a shorted square disc. A resonance of the shorted square disc may be coupled to a resonance of the square folded strip line so as to form a wide bandwidth of about 36.6% of a central frequency of 2.313 GHz based on a VSWR?2. Also, rectangular slits may be inserted into the perpendicular ground plane to improve a distortion of a radiation pattern that forms on the perpendicular ground plane so as to reduce a backward radiation by 3 dBi or more. The small broadband monopole antenna exhibits a forward radiation pattern similar to that of a general monopole antenna and has a gain of about 2.6 dBi within a bandwidth.

Abstract: A monopole antenna capable of implementing an MMIO system, which includes a ground part formed of plate metal, a monopole antenna element connected to one side of the ground part and formed of strips bent multiple times, an auxiliary antenna element connected to one side of the ground part and disposed adjacent to the monopole antenna element to electrically connect to the monopole antenna element, and a short-circuit part interconnecting the monopole antenna element and the auxiliary antenna element. Accordingly, the monopole antenna element is bent multiple times so that the antenna can become compact in less than half a width compared to the conventional antenna, and when the MIMO system is constructed, the interference between the respective antennas can be reduced so that the array antenna can become compact in size.

Abstract: A small broadband monopole antenna including a shorted patch and a probe with a strip line that are electromagnetically coupled with each other. The probe with a strip line has a length of about ?/4, where ? is a wavelength. The strip line may be one of a spiral type, a folded type and a helix type. A resonance frequency of the antenna can be adjusted by varying the inductance and the capacitance of the resonance circuits. In addition, a double-band antenna or a single-band antenna having a broad bandwidth can be designed in accordance with application purpose of the antenna.

Abstract: A flat-plate MIMO array antenna includes a substrate, a plurality of antenna elements disposed on the substrate, and at least one isolation element interposed between a plurality of antenna elements on the substrate and connected to a ground. Mutual interference between the antenna elements is prevented by the isolation element formed between the antenna elements, thereby preventing the distortion of the radiation pattern. Also, since the isolation element is grounded to the ground surface, the isolation element operates as a parasitic antenna, thereby increasing the output gain.

Abstract: Provided is a dual band antenna including: a ground surface; a feeder feeding a predetermined current; an induction radiator including one end connected to the ground surface and the other end connected to the feeder; and a parasitic radiator including an end connected to the ground surface and the other end opened. An antenna having a smaller size than an existing IFA mainly used as an internal antenna in a portable terminal can be provided through the dual band antenna including the induction radiator and the parasitic radiator.

Abstract: A plate board type MIMO (multiple-input multiple-output) array antenna including a board, a plurality of antenna elements manufactured on the board, and an isolation unit offsetting effects of electromagnetic waves radiated from the plurality of antenna elements on the other antenna elements of the plurality of antenna elements. In a case where two antenna elements are used, the isolation unit may include at least one isolation element positioned within a space between the two antenna elements on the board and symmetric with respect to a center of a distance between the two antenna elements.

Abstract: A small broadband monopole antenna having a perpendicular ground plane with an electromagnetically coupled feed is provided. The small broadband monopole antenna may be realized as a small antenna having a size of 0.085?0×0.085?0×0.085?0 by positioning a folded strip line under a shorted square disc. A resonance of the shorted square disc may be coupled to a resonance of the square folded strip line so as to form a wide bandwidth of about 36.6% of a central frequency of 2.313 GHz based on a VSWR?2. Also, rectangular slits may be inserted into the perpendicular ground plane to improve a distortion of a radiation pattern that forms on the perpendicular ground plane so as to reduce a backward radiation by 3 dBi or more. The small broadband monopole antenna exhibits a forward radiation pattern similar to that of a general monopole antenna and has a gain of about 2.6 dBi within a bandwidth.

Abstract: A transmission line conversion apparatus connecting a parallel transmission line to a coplanar waveguide (CPW) is provided. To this end, the CPW including a transmission line composed of a signal line and a ground line which is formed on one surface of a dielectric substrate, and a parallel transmission line connected to the CPW, at a predetermined angle with respect to a substrate constituting the CPW, and composed of a signal line and a ground line, are proposed. In addition, the signal line of the CPW and the signal line of the parallel transmission line are connected to each other, and the ground line of the CPW and the ground line of the parallel transmission line are connected to each other. As such, by connecting the CPW to the parallel transmission line, a return loss can be minimized.

Abstract: An improved and more compact structure of a built-in antenna for handheld terminals, improving radiation pattern and efficiency. Provided is a planar inverted-F antenna having a radiation part having an inductive radiation portion and a parasitic radiation portion which are spaced in a certain distance apart from a ground surface, a power-supply part horizontally spaced apart from the ground surface and for directly supplying currents to the connected inductive radiation portion, and connection parts for connecting the radiation portions to the ground. The planar inverted-F antenna has an inductive antenna portion and a parasitic antenna portion, thereby reducing its volume compared to the conventional inverted-F antenna. Complicated manufacturing and processing procedures are simplified by connecting the power-supplying part and a PCB.

Abstract: A small broadband monopole antenna including a shorted patch and a probe with a strip line that are electromagnetically coupled with each other. The probe with a strip line has a length of about ?/4, where ? is a wavelength. The strip line may be one of a spiral type, a folded type and a helix type. A resonance frequency of the antenna can be adjusted by varying the inductance and the capacitance of the resonance circuits. In addition, a double-band antenna or a single-band antenna having a broad bandwidth can be designed in accordance with application purpose of the antenna.