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In this study, a fixed-point-based beamforming coefficient calculator is proposed for the beamforming of a digital active array radar. Floating-point-based calculations enable precise calculations but have the disadvantages of high computational complexity and latency. To complement this, the proposed fixed-point-based beamforming coefficient calculation had a high signal to quantization noise ratio (SQNR) of 51.35 dB and the beam steering angle error was between −0.05° and 0.05° when compared with those of the floating-point calculation; these satisfied the system requirements. The proposed fixed-point-based beamforming coefficient calculator was implemented on a Xilinx Kintex UltraScale FPGA. It could reduce 54.94 % CLB register, 44.33 % CLB LUT, 60 % DSP slice, and −58.16 % latency than the floating-point calculator. Furthermore, at small beam pattern powers, the performance degradation of the calculator was less compared with previous research. [ABSTRACT FROM AUTHOR]

In this study, motion compensation for electronic beams in sea environments is proposed. Because the radar on a ship fluctuates according to the sea environment, it is necessary to compensate for the fluctuation to achieve accurate beam steering. Unlike the fluctuations in the pitch and yaw directions, where only compensation for the beam steering value is required, the fluctuation in the roll direction causes the beam to rotate. Therefore, compensation for the rotation of the beam in the roll direction is necessary. For this purpose, beam rotation and 2-D beam steering were performed. Finally, the proposed method is applied to a 20×20 array and verified. [ABSTRACT FROM AUTHOR]

Ultra-wideband (UWB) technology appeared as a short-range wireless communication technology 20 years ago, but competing technologies, such as Wi-Fi, attracted more interest. However, UWB technology has recently been re-evaluated because it makes it possible to measure the distance between wireless devices. In particular, UWB chips were released by NXP and Qorvo, and, as Samsung and Apple began installing UWB technology in smartphones, it began to be popularized. It is expected that UWB technology will be used in connection with smartphones in various location-based fields, such as automobiles, smart factories, and smart homes. Although the importance of UWB technology is increasing in various fields, as described above, the research on the principles and characteristics of the latest UWB positioning technology has been inadequate. Therefore, to help readers systematically understand the latest UWB positioning technology, the principle of UWB positioning technology is explained, and the latest research and development, as well as commercialization trends, are described. [ABSTRACT FROM AUTHOR]

This paper proposes a three-dimensional 24 GHz frequency modulated continuous-wave (FMCW) radar transmitter for long-range detection. The proposed transmitter implements seven switched vertical fan beams from 15° to −15° for high effective isotropic radiated power (EIRP) and vertical angle detection. Instead of using lossy electronic switches and large passive beamforming networks, the beamforming transmitter is achieved by directly switching the power amplifier, which drives a sectoral series patch array antenna. The EIRP of each beam is approximately 48.676 dBm, and the size of the transmitter is 27.5 cm × 11 cm. [ABSTRACT FROM AUTHOR]

Digital adaptive beamforming is applied to the radar system to ensure system performance in an interference environment. For real time application to an actual radar system with a large number of antenna elements, the dimensions of the adaptive beamforming coefficient must be reduced. In this paper, we propose a beam domain localized adaptive beam forming algorithm based on linear constrained minimum variance (LCMV) that considers system applicability while maintaining the performance of fully adaptive beamforming. Jammer detection and angle estimation are performed using a passive listening signal, and the dimensions are reduced by localizing the signal to the beam domain based on jammer information and pre-determined linear constraints. Estimation of the interference covariance matrix and adaptive beamforming are performed in the reduced beam domain to ensure real-time operation and applicability. To verify the performance of the proposed algorithm, we analyzed the results compared to the fully adaptive beamforming in terms of signal-to-interference plus noise ratio (SINR) loss and maximum side lobe level in the presence of a jamming signal. [ABSTRACT FROM AUTHOR]

In this paper, we propose a widerange array microphone for lecturer tracked with Frequency Modulated Continuous Waveform (FMCW) radar sensor. Time Difference-of-Arrival (TDoA) is often used as audio tracking, but the tracking accuracy is poor because the frequency of the voice is low and the relative frequency change is large. FMCW radar has a simple structure and is used to detect obstacles for vehicles, and the resolution can be archived to several centimeter. It is shown that the sensor is useful for detecting a speaker in open area such as a lecture, and we propose an wide range 4-element array microphone beamforming system. Through some experiments, the proposed system is able to adequately track the location and showed a 8.6dB improvement over the selection of the best microphone. [ABSTRACT FROM AUTHOR]

A method to improve the tracking accuracy of low-altitude sea targets is proposed using an adaptive beamforming algorithm in a multipath environment. It is confirmed that the target elevation can be estimated with relatively high accuracy without repetitive calculation using the proposed method in analog beamforming active electronically scanned array radar. The proposed method improves the tracking accuracy by adding a side-lobe suppression condition to the existing adaptive beamforming constraint for mono pulse inclination control while accounting for the characteristics of the low-altitude sea target with less elevation change. In addition, various adaptive beamforming algorithms were applied to the proposed method, and the results were compared and analyzed to optimize tracking accuracy. [ABSTRACT FROM AUTHOR]

Beamforming technology has been extensively applied in the field of 5G mobile communication and radar in recent years; it has also been applied in technological fields where it was not previously utilized. Conventional beamforming technology cannot be applied immediately to low-power IoT wireless communication because of issues such as high power consumption and price; thus, single-channel beamforming technology capable of low-power operation using switched array antennas is required. Therefore, in this paper, we examine the characteristics of the Bluetooth 5.1 standard, according to which a recent switched array antenna single-channel beamforming technology is applied, along with the requirements of the beamforming technology in low-power IoT wireless communication. In addition, the experimental results of direction finding using a two-element switch array antenna are presented. Based on this, we suggest the implications of applying beamforming technology in various low-power IoT wireless communication fields. [ABSTRACT FROM AUTHOR]

In a multi-function radar, the adaptive beamforming algorithm is one of the several methods that can be applied to restore the degraded SINR(Signal-to-Interference Noise Ratio) to its original level. This algorithm is employed for the regular operation of radars in jamming situations, when unwanted high-power signals are received. In this paper, we introduce a few adaptive beamforming algorithms that can be applied to a multi-function digital radar in jamming situations. Furthermore, we compare and analyze the adaptive beamforming performance in terms of SINR and sidelobe level characteristics by applying each algorithm to a specific planar array comprising optimized subarray structures. [ABSTRACT FROM AUTHOR]

Direction finding is a traditional technique that was initially used in radio surveillance. Since its inception, antenna-based direction finding technology has become the core technology in various fields, such as radar(to find the direction of the target) and mobile communication(where MIMO-based multi-antennas are used). Moreover, use of the direction finding technology in the field of IoT, such as in Bluetooth, is increasing. Thus, the importance of direction finding technology is growing in various fields. However, it continues to be treated as a sub-technology of radio surveillance, radar, and wireless communication. The aim of this paper is to help readers systematically understand direction finding technology. Accordingly, a systematic classification and analysis of each characteristic of direction finding technology, along with recent research and development trends for it, are discussed in the paper. [ABSTRACT FROM AUTHOR]