Automatic Beam Steering Research Articles

24-GHz 4TX–4RX Phased Array Transceiver With Automatic Beam Steering Mode for FMCW Radar Applications

24-GHz 4TX–4RX Phased Array Transceiver With Automatic Beam Steering Mode for FMCW Radar Applications

Bi-Directional All-Optical Wireless Gigabit Ethernet Communication System Using Automatic Self-Aligned Beam Steering

Bi-Directional All-Optical Wireless Gigabit Ethernet Communication System Using Automatic Self-Aligned Beam Steering

6G Indoor Network Enabled by Photonics- and Electronics-Based sub-THz Technology

We propose an indoor network with a sub-terahertz- band wireless link for 6G applications. In our proposed indoor network, an optical hub unit (OHU) that controls the entire system is optically linked to THz remote nodes (RNs) over optical distribution fibers. The THz RNs communicate with the user equipment through a sub-THz wireless link. The function of the THz RNs is to provide an interface between the optical link and the sub-THz wireless link. For downlink transmission, a photonics-based sub-THz-band signal generation method is adopted to take advantage of the broadband characteristics of the optical components. An electronics-based sub-THz mixer is also used for uplink transmission because of its cost-effectiveness and low energy consumption. A digital signal processor (DSP) is designed to recover the original transmitted baseband signal. The DSP provides frequency offset compensation over a wide frequency range and reduces the probability of cyclic slip. The performance of the proposed system was investigated experimentally with commercially available optical/electrical components. We demonstrate 100 Gb/s 2.5-m wireless transmission with a 16-quadrature amplitude modulation (16-QAM) signal for configuring the downlink. The optical transmission distance was set to 10 km, and the power penalty measured by optical transmission was negligible. We also investigated the scalability and tunability of the photonics-based sub-THz transmitter to confirm the upgradability of our proposed indoor network to consider future capacity expansion. To establish an uplink, a 25 Gb/s 1.5-m wireless transmission with a quadrature phase shift keying (QPSK) signal was employed. A directly modulated laser was used for cost-effective optical transmission. Unlike downstream transmission, a measured bit error rate (BER) penalty caused by the optical transmission was observed. This is due to the interplay between the frequency chirp of the directly modulated laser and the chromatic dispersion in the fiber. Despite this penalty, BERs less than the soft-decision forward error correction (FEC) threshold (2 × 10^−2) with 20% overhead were achieved. We discuss several remaining technical challenges in real-field deployment. These include THz Tx power improvement, photonic integration, reducing form-factor, polarization insensitivity, and automatic beam steering. Our recent efforts to address these issues are also introduced and examined.

Fast Millimeter Wave Assisted Beam-Steering for Passive Indoor Optical Wireless Networks

In light of the extreme radio congestion, the time has come to consider the upper parts of the electromagnetic spectrum. Optical beam-steered wireless communications offer great potential for future indoor short-range connectivity, due to virtually unlimited available bandwidth and lack of interference. However, such networks require fast automatic beam-steering solutions. In this letter, we propose a novel optical beam-steering approach that exploits coarse grained millimeter wave localization to significantly reduce optical beam-steering time. We formulate it as a search problem that is NP-hard to solve optimally. Moreover, we present the MMW-OBS heuristic that efficiently solves it in real-time. Results show that MMW-OBS provides total steering times below 1 s using state of the art millimeter wave localization, which is already sufficient to support sporadically mobile devices.

Overnight non-contact continuous vital signs monitoring using an intelligent automatic beam-steering Doppler sensor at 2.4 GHz.

Doppler-based non-contact vital signs (NCVS) sensors can monitor heart rates, respiration rates, and motions of patients without physically touching them. We have developed a novel single-board Doppler-based phased-array antenna NCVS biosensor system that can perform robust overnight continuous NCVS monitoring with intelligent automatic subject tracking and optimal beam steering algorithms. Our NCVS sensor achieved overnight continuous vital signs monitoring with an impressive heart-rate monitoring accuracy of over 94% (i.e., within ±5 Beats-Per-Minute vs. a reference sensor), analyzed from over 400,000 data points collected during each overnight monitoring period of ~ 6 hours at a distance of 1.75 meters. The data suggests our intelligent phased-array NCVS sensor can be very attractive for continuous monitoring of low-acuity patients.

Mutually exclusive data encoding for realization of a full duplexing self-steering wireless link using a retrodirective array transceiver

A two-way communication link is established between an interrogator and retrodirective antenna array. The link is realized by using standard time-domain modulation for data uplink to the retrodirective array, while outgoing data is coded onto the antenna polarization sense of the signal sent back to the interrogator. Using these noninterfering mutually exclusive modulations schemes, this system architecture is able to resolve the difficulty of dealing with the corruption of the outgoing retrodirected signal by the incoming interrogation signal inherent when using phase-conjugation mixers (PCMs). This paper will discuss the development of a novel PCM also used for polarization modulation and a polarization state detector for demodulation. Analysis of circuit design tolerances and affects of jammers on proper polarization detection is also shown. Demonstration of simultaneous data transfer is presented in simulation and measurement along with the array's automatic beam-steering ability.

A Full Duplex Capable Retrodirective Array System for High-Speed Beam Tracking and Pointing Applications

A retrodirective array capable of full duplex communication is presented. The system is based purely on analog circuits for all signal-processing tasks including target tracking, beam pointing, and carrier recovery. Two types of receiver architectures are used, i.e., AM diode detectors for near-omni directional coverage and a digital beamforming receiver to enhance signal-to-interference ratio. This paper also discusses this technology in the context of development of a radar target/communication device, which is intended to both facilitate radar imaging and establish a self-tracking communication link between the ground terminal and mobile radar station. Demonstration of 10-Mb/s data receiving and transmitting functions are presented along with its automatic beam-steering ability and radiation patterns, as well as details about each major circuit component used in the array.

Automatic beam steering in the NSLS storage rings using closed orbit feedback

This paper describes recent work on beam stabilization systems for the NSLS electron storage rings. It also reviews several types of detectors presently available for monitoring beam motion and describes possible schemes for stabilizing photon beams in a storage ring. Finally, it briefly discusses plans for simultaneous stabilization of many beam lines in the storage rings.