scholarly journals GNSS Array Antenna for Mitigating Multipath Errors in Urban Environment

2019 ◽  
Vol 94 ◽  
pp. 03009
Author(s):  
Toshiaki Tsujii ◽  
Kenta Yonebayashi ◽  
Takeshi Fujiwara ◽  
Sohshi Ohsawa
Keyword(s):  
Urban Environment ◽  
Array Antenna ◽  
Test Results ◽  
Front End ◽  
Rf Front End ◽  
Hardware Biases ◽  
Proper Weight ◽  
Multipath Errors

GNSS signal vulnerability has been a major concern especially for safety-of-life applications such as aircraft operations. Therefore, a GNSS array antenna technology was investigated focusing on beamforming to mitigate multipath errors in urban environment including airport surfaces. A commercial three-element GNSS antenna and RF-Front end were used to obtain digital IF data. The recorded In-phase/Quadrature IF data for three antennas were combined with proper weight to form beams towards satellites after so-called hardware biases were calibrated. Test results in multipath-rich environment demonstrated that 50-70% reduction of pseudorange errors due to multipath were possible if the beamforming algorithms were applied.

Substrate integrated waveguide fed printed dipole array antenna for isolating the RF front-end from the antenna

2008 ◽  
Vol 51 (2) ◽  
pp. 557-562 ◽  
Author(s):  
Chen Yu ◽  
Wei Hong ◽  
Z. Q. Kuai ◽  
J. X. Chen ◽  
Ling Tian ◽  
...  
Keyword(s):  
Array Antenna ◽  
Substrate Integrated Waveguide ◽  
Front End ◽  
Rf Front End

scholarly journals Verification of Antenna Sensor with Commercial Handsets By Applying Radiative Calibration Method

2019 ◽  
pp. 1-6
Keyword(s):  
Reflection Coefficient ◽  
Calibration Method ◽  
Test Results ◽  
Excellent Performance ◽  
Proximity Sensor ◽  
Front End ◽  
Rf Front End

This paper describes an antenna proximity sensor for mobile and applications based on the measured reflection coefficient using a bidirectional coupler. A bidirectional coupler which uses forward and reverse parameters is located between radiated antenna and RFFE (RF Front-End). The measured reflection coefficient proved high chances to act as an antenna sensor. The proposed antenna proximity sensor showed excellent performance and some of the test results with Samsung smartphone are attached to prove it.

scholarly journals Design and simulation of an analog beamforming phased array antenna

2020 ◽  
Vol 10 (2) ◽  
pp. 1398
Author(s):  
Mohamed Elhefnawy
Keyword(s):  
Phase Shift ◽  
Antenna Array ◽  
Phased Array ◽  
Axial Ratio ◽  
Array Antenna ◽  
Design System ◽  
Phased Array Antenna ◽  
Front End ◽  
Rf Front End ◽  
Simulation Results

In this paper, a phased array antenna is designed and simulated. The antenna array consists of four circularly polarized slotted waveguide elements. The antenna array is simulated using CST MWS. The simulation results for the proposed antenna array at different values of progressive phase shift demonstrate that the S‒parameters for all four ports are less than ‒10 dB over at least 2% bandwidth, the simulated maximum gain is 13.95 dB, the simulated beamwidth can be 19˚ or narrower based on the value of the progressive phase shift. , the range of frequencies over which the simulated Axial Ratio (AR) is below 3 dB is not fixed and varied according to the selected progressive phase shift. The proposed four-element RF front-end is simulated using Advanced Design System (ADS) at operating frequency of 9.6 GHz. The obtained simulation results by ADS indicate the feasibility of implementing the proposed RF-front end for feeding the antenna array to realize analog beamforming.

scholarly journals Optimum power transfer in RF front end systems using adaptive impedance matching technique

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Alibakhshikenari ◽  
Bal S. Virdee ◽  
Leyre Azpilicueta ◽  
Chan H. See ◽  
Raed Abd-Alhameed ◽  
...  
Keyword(s):  
Impedance Matching ◽  
Adaptive Antenna ◽  
Power Transfer ◽  
Control Loops ◽  
Matching Networks ◽  
Front End ◽  
Rf Front End ◽  
Matching Technique ◽  
Digital Circuitry ◽  
Communications System

AbstractMatching the antenna’s impedance to the RF-front-end of a wireless communications system is challenging as the impedance varies with its surround environment. Autonomously matching the antenna to the RF-front-end is therefore essential to optimize power transfer and thereby maintain the antenna’s radiation efficiency. This paper presents a theoretical technique for automatically tuning an LC impedance matching network that compensates antenna mismatch presented to the RF-front-end. The proposed technique converges to a matching point without the need of complex mathematical modelling of the system comprising of non-linear control elements. Digital circuitry is used to implement the required matching circuit. Reliable convergence is achieved within the tuning range of the LC-network using control-loops that can independently control the LC impedance. An algorithm based on the proposed technique was used to verify its effectiveness with various antenna loads. Mismatch error of the technique is less than 0.2%. The technique enables speedy convergence (< 5 µs) and is highly accurate for autonomous adaptive antenna matching networks.

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