Abstract: The detection and identification of unmanned aerial vehicles (UAVs) from a radio wave measurement result based on artificial intelligence (AI) are provided. A method of operating an apparatus to detect unmanned aerial vehicles (UAVs) includes generating a spectrogram, determining a first region to find a direction of the UAVs in the spectrogram, determining a direction of a first UAV of the UAVs based on signal values in the first region, determining a second region to identify a type of the first UAV in the spectrogram, and identifying the type of the first UAV based on signal values in the second region.

Abstract: The present disclosure relates to an apparatus and method for removing noise for a weather radar and, more particularly, to an apparatus and method for removing noise for a weather radar, the apparatus and method being able to detecting a radio interference echo, which is noise due to radio interference that is generated by reception of other external radio waves to a weather radar except for a radio wave transmitted from the weather radar, separately from weather eco according to normal weather measurement, and being able to remove the radio interference echo.

Abstract: Provided are an apparatus and a method for removing noise for observation information of a weather radar, and more particularly, an apparatus and a method for removing noise for observation information of a weather radar capable of separating and removing second trip echoes corresponding to noise from precipitation echoes by simulating the reflectivity of the second trip echoes caused by a distance folding phenomenon shown in weather observation information generated using a weather radar. According to the present invention, in order to remove the second trip echo that occurs in the observation information measured in the volume observation radius during weather observation by setting the weather radar as the volume observation radius where the second trip echo occurs, the weather radar is set as a long-range observation radius in which a second trip echo exceeding the volume viewing radius does not occur.

Abstract: An apparatus and a method for estimating rainfall of hail and rain using a dual-polarization weather radar improve accuracy of classification of hail and rain zones and estimation of rainfall intensity by classifying hail and rain zones using a distribution of horizontal reflectivity and differential reflectivity of radar observation values, discriminating between a convective zone and a stratiform zone depending on reflection intensity, and applying a dual-polarization-based rainfall estimating relational equation for each type in a weighted mean technique.

Abstract: Provided are an apparatus and a method for removing noise for observation information of a weather radar, and more particularly, an apparatus and a method for removing noise for observation information of a weather radar capable of separating and removing second trip echoes corresponding to noise from precipitation echoes by simulating the reflectivity of the second trip echoes caused by a distance folding phenomenon shown in weather observation information generated using a weather radar. According to the present invention, in order to remove the second trip echo that occurs in the observation information measured in the volume observation radius during weather observation by setting the weather radar as the volume observation radius where the second trip echo occurs, the weather radar is set as a long-range observation radius in which a second trip echo exceeding the volume viewing radius does not occur.

Abstract: An apparatus and a method for estimating rainfall of hail and rain using a dual-polarization weather radar improve accuracy of classification of hail and rain zones and estimation of rainfall intensity by classifying hail and rain zones using a distribution of horizontal reflectivity and differential reflectivity of radar observation values, discriminating between a convective zone and a stratiform zone depending on reflection intensity, and applying a dual-polarization-based rainfall estimating relational equation for each type in a weighted mean technique.

Abstract: The present invention provides an array antenna apparatus for a rotation mode, a wireless communication terminal, and a method thereof. The apparatus according to the exemplary embodiment includes an antenna array including a plurality of antenna elements; and a control unit which determines an antenna pattern in accordance with a transmission/reception characteristic of a signal and assigns a weight to antenna elements in a position corresponding to the determined antenna pattern on the antenna array to implement a rotation mode antenna based on the antenna element to which the weight is assigned.

Abstract: The present invention relates to a reception apparatus. The reception apparatus includes a plurality of reception antennas; and a signal processing unit configured to use reception characteristic of the plurality of reception antennas, wherein the signal processing unit comprises a channel estimation unit configured to respectively estimate a channel response matrix of each signal received via the plurality of reception antennas, and a coding unit configured to define a coding matrix based on an inverse matrix of the estimated channel response matrix, and to obtain a final output signal corresponding to each reception antenna by applying the coding matrix to each received signal.

Abstract: The present invention relates to a reception apparatus. The reception apparatus includes a plurality of reception antennas; and a signal processing unit configured to use reception characteristic of the plurality of reception antennas, wherein the signal processing unit comprises a channel estimation unit configured to respectively estimate a channel response matrix of each signal received via the plurality of reception antennas, and a coding unit configured to define a coding matrix based on an inverse matrix of the estimated channel response matrix, and to obtain a final output signal corresponding to each reception antenna by applying the coding matrix to each received signal.

Abstract: A radio measurement apparatus comprising: an array antennal selection unit selecting array antennas corresponding to received signals; a reference path selection unit selecting a reference array antenna; a signal processing unit selecting a reference antenna channel through analysis of signal characteristics measured through two reception channels; a sequential channel multiplex unit determining sequentially inputting received signals of remaining array antennas to output the sequentially input signals to a receiver; and a correction signal input unit compensating amplitude and phase characteristics of the respective reception channels.

Abstract: Provided is an apparatus for calibrating a transmission path, the apparatus including one or more couplers to separate, by one or more paths, one or more input signals input from an input terminal of one or more antennas, a power detector to detect amplitude of one or more path signals separated by the one or more paths, a power distributor to distribute any one of the one or more path signals, one or more mixers to mix a distribution signal distributed by the power distributor with the one or more path signals, a low-pass filter to remove a high-frequency component of a mixed signal mixed by the one or more mixers; and a voltage detector to detect amplitude of one or more filter pass signals with the high-frequency component removed.

Abstract: Provided is an apparatus for calibrating a transmission path, the apparatus including one or more couplers to separate, by one or more paths, one or more input signals input from an input terminal of one or more antennas, a power detector to detect amplitude of one or more path signals separated by the one or more paths, a power distributor to distribute any one of the one or more path signals, one or more mixers to mix a distribution signal distributed by the power distributor with the one or more path signals, a low-pass filter to remove a high-frequency component of a mixed signal mixed by the one or more mixers; and a voltage detector to detect amplitude of one or more filter pass signals with the high-frequency component removed.

Abstract: The present invention provides an array antenna apparatus for a rotation mode, a wireless communication terminal, and a method thereof. The apparatus according to the exemplary embodiment includes an antenna array including a plurality of antenna elements; and a control unit which determines an antenna pattern in accordance with a transmission/reception characteristic of a signal and assigns a weight to antenna elements in a position corresponding to the determined antenna pattern on the antenna array to implement a rotation mode antenna based on the antenna element to which the weight is assigned.

Abstract: A wideband RF receiver includes a dual mode antenna configured to drive in an active antenna mode when a bias power is supplied thereto and to drive in a passive antenna mode when a power is not supplied thereto; and a hybrid interface apparatus configured to supply the bias power to the dual mode antenna and configured to provide a control signal that enables the dual mode antenna to drive in the active antenna mode or the passive antenna mode. Further, the wideband RF receiver includes a radio measuring and receiving apparatus configured to measure a signal level of an input value that the hybrid interface apparatus outputs the control signal.

Abstract: A radio measurement apparatus comprising: an array antennal selection unit selecting array antennas corresponding to received signals; a reference path selection unit selecting a reference array antenna; a signal processing unit selecting a reference antenna channel through analysis of signal characteristics measured through two reception channels; a sequential channel multiplex unit determining sequentially inputting received signals of remaining array antennas to output the sequentially input signals to a receiver; and a correction signal input unit compensating amplitude and phase characteristics of the respective reception channels.

Abstract: A digital spectrum analysis apparatus and method for direction finding (DF) and location is provided. The digital spectrum analysis apparatus includes: a multi-channel unit configured to convert signals inputted from antennas into digital signals, reduce a sampling rate of the digital signals by using a digital down converter (DDC), and convert the digital signals into baseband complex signals, and having a plurality of channels; a DF estimator configured to estimate the direction of the signal; a spectrum processing unit configured to map any one of a bearing and a power level of the baseband complex signal into coordinate system, and allocate different colors to one of the bearings and the power levels depending on the accumulation ratio of one of the bearing and the power level; and a display unit configured to display the power level and the bearing with colors.

Abstract: A log periodic antenna includes first and second transmission lines parallel with each other; and a plurality of broadband radiation elements having first sides electrically connected to the first and second transmission lines, a predetermined angle being defined between the first sides of the broadband radiation elements and the first and second transmission lines, and second sides not electrically connected with the first and second transmission lines, the second sides having radiation surfaces larger than radiation surfaces of the first sides. A plurality of broadband radiation elements electrically connected with the first transmission line and a plurality of broadband radiation elements electrically connected with the second transmission line are positioned to face each other with reference to the first and second transmission lines.

Abstract: Provided is a method of selecting a white Gaussian noise sub-band using singular value decomposition (SVD). The method includes selecting a first frequency band, verifying whether a signal is included in the selected first frequency band, determining the first frequency band as a target measurement frequency when the signal is not included in the selected first frequency band, and measuring a background radio noise in the determined target measurement frequency.

Abstract: A digital spectrum analysis apparatus and method for direction finding (DF) and location is provided. The digital spectrum analysis apparatus includes: a multi-channel unit configured to convert signals inputted from antennas into digital signals, reduce a sampling rate of the digital signals by using a digital down converter (DDC), and convert the digital signals into baseband complex signals, and having a plurality of channels; a DF estimator configured to estimate the direction of the signal; a spectrum processing unit configured to map any one of a bearing and a power level of the baseband complex signal into coordinate system, and allocate different colors to one of the bearings and the power levels depending on the accumulation ratio of one of the bearing and the power level; and a display unit configured to display the power level and the bearing with colors.

Abstract: The present invention provides a real-time noise reduction apparatus for a radio monitoring system, including a dual channel digitizing unit configured to convert signals, subject to frequency down-conversion and inputted to two channels, into digital signals and a Digital Signal Processor (DSP) configured to reduce noise from time sample regions of the signals, received from the dual channel digitizing unit, in a time domain using a correlation method between samples through the delayed feedback means.