Active antenna

About: Active antenna is a research topic. Over the lifetime, 2246 publications have been published within this topic receiving 26493 citations.

Management of deformable active antenna

Abstract: Radar systems on ground and naval basements require an improvement of flexibility to provide low cost solutions with better tactical deployment and to open new capacities for implementation. We propose to dynamically cope with distortions of radiating panels with an innovative method based on an accurate mechanical modelling under different load scenarii. In conjunction with either auto-calibration algorithms or instrumented technique, our method allows to recover high quality radiating patterns and to preserve radar system performances.

3D beamforming for capacity boosting in LTE-advanced system

Abstract: LTE-Advanced system has been deployed with 2 and 4 transmission antennas (Tx) while the specification supports up to 8Tx. Due to deployment space, antenna dimension and complexity, operators have not been interested in the deployment of 8Tx systems. Recently, three dimensional (3D) beamforming using 2D active antenna array has attracted significant attention in the wireless industry. By incorporating 2D active array into LTE-A systems, the system offers freedom in controlling radiation on elevation and horizontal dimension. In addition, 2D array antenna increases the number of antennas without exceeding form-factor where the conventional antennas are deployed. When the number of antennas increases in the form of 2D arrangement, spatial separation can be realized simultaneously in horizontal and elevation domain and vertical beam-steering can increase SINR of UEs in high floors. In this paper, we study the system operations and implementations for supporting 3D beamforming with 8Tx antennas. In our schemes, by reusing the conventional CSI feedback framework, the system can operate 2D active array without harming the backward compatibility. Evaluation results show that 3D beamforming provides capacity boosting over the conventional 2D beamforming systems while keeping same antenna structure.

Tri-band active patch slot antennas for angular observations using GLONASS/GPS signals

Abstract: Tri-band (L1/L2/L3) active patch slot leaky-wave antennas with the right-hand circular polarization for angular observations using the signals of the Global navigation satellite systems GLONASS/GPS have been designed. The antenna positioning accuracy in the horizontal and vertical planes as well as in the angular observations has been estimated. Measurements have been made in the L1 frequency band using the combined GLONASS/GPS constellation. It has been shown that the positioning root-mean-square-error (RMSE) of an active antenna relative to another one in the horizontal plane is less than 2.2 mm, and in the vertical plane it is less than 1.8 mm. RMSE of the positioning by the yaw, roll and pitch angles at a distance of 0.7m between the centers of three antennas does not exceed 9 angular minutes, while at a distance of 2 m it does not exceed 4 angular minutes.

Performance of the Shuttle Radar Topography Mission, X-band radar system

Abstract: The German contribution to the Shuttle Radar Topography Mission (SRTM) is an X-band SAR Interferometer. In 1994 successfully flown flight hardware from the Shuttle radar lab is reused and modified to form a single pass interferometer. The original system is used as the prime channel with the radar transmitter and the channel one receiver. The secondary receive only channel is a new design with an electronically steering antenna beam using existing spare parts like the antenna panels for the 6 meter long array. The steering capability became necessary to compensate for the mast dynamics to keep the prime and secondary antenna beams aligned in azimuth. The performance degradation by using only half of the antenna length compared to the prime channel is recovered by using better low noise amplifiers and by avoiding long corporate feed networks. To optimize the radar parameters special developed software tools are used. Based on a low-resolution backscatter and height map from the Earth, the gain settings and the receiver window presettings are calculated and monitored real-time. This paper describes the X-SAR instrument monitoring concept and reports about the performance, the experience and results from the SRTM mission early this year.

The first detection of the solar U+III association with an antenna prototype for the future lunar observatory

Abstract: We report about observations of the solar U+III bursts on 5 June of 2020 by means of a new active antenna designed to receive radiation in 4-70 MHz This instrument can serve as a prototype of the ultra-long-wavelength radiotelescope for observations on the farside of the Moon Our analysis of experimental data is based on simultaneous records obtained with the antenna arrays GURT and NDA in high frequency and time resolution, e-Callisto network as well as by using the space-based observatories STEREO and WIND The results from this observational study confirm the model of Reid and Kontar (2017)