scholarly journals A Robust Design for Aperture-Level Simultaneous Transmit and Receive with Digital Phased Array

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 109
Author(s):  
Mingcong Xie ◽  
Xizhang Wei ◽  
Yanqun Tang ◽  
Dujuan Hu
Keyword(s):  
Interference Cancellation ◽  
Single Phase ◽  
Phase Array ◽  
Excellent Performance ◽  
Initial Value ◽  
Random Group ◽  
Array Design ◽  
Theoretical Support ◽  
Overall Performance ◽  
Element Array

Aperture-level simultaneous transmit and receive (ALSTAR) attempts to utilize adaptive digital transmit and receive beamforming and digital self-interference cancellation methods to establish isolation between the transmit and receive apertures of the single-phase array. However, the existing methods only discuss the isolation of ALSTAR and ignore the radiation efficiency of the transmitter and the sensitivity of the receiver. The ALSTAR array design lacks perfect theoretical support and simplified engineering implementation. This paper proposes an adaptive random group quantum brainstorming optimization (ARGQBSO) algorithm to simplify the array design and improve the overall performance. ARGQBSO is derived from BSO and has been ameliorated in four aspects of the ALSTAR array, including random grouping, initial value presets, dynamic probability functions, and quantum computing. The transmit and receive beamforming carried out by ARGQBSO is robust to all elevation angles, which reduces complexity and is conducive to engineering applications. The simulated results indicate that the ARGQBSO algorithm has an excellent performance, and achieves 166.8 dB of peak EII, 47.1 dBW of peak EIRP, and −94.6 dBm of peak EIS with 1000 W of transmit power in the scenario of an 8-element array.

scholarly journals An Initial Value Estimation Method for the Kalman and Extended Kalman Filters in Underground Metal Detection

2019 ◽  
Vol 9 (19) ◽  
pp. 4113 ◽  
Author(s):  
Yadong Wan ◽  
Zhen Wang ◽  
Peng Wang ◽  
Zhiyang Liu ◽  
Na Li ◽  
...  
Keyword(s):  
Kalman Filter ◽  
Estimation Method ◽  
Detection Methods ◽  
Polarizability Tensor ◽  
Filter Method ◽  
Excellent Performance ◽  
Initial Value ◽  
Initial State ◽  
Metal Detection ◽  
Value Estimation

As an underground metal detection technology, the electromagnetic induction (EMI) method is widely used in many cases. Therefore, the EMI detection algorithms with excellent performance are worth studying. One of the EMI detection methods in the underground metal detection is the filter method, which first obtains the secondary magnetic field data and then uses the Kalman filter (KF) and the extended Kalman filter (EKF) to estimate the parameters of metal targets. However, the traditional KF methods used in the underground metal detection have an unsatisfactory performance of the convergence as the algorithms are given a random or a fixed initial value. Here, an initial state estimation algorithm for the underground metal detection is proposed. The initial state of the target’s horizontal position is estimated by the first order central moments of the secondary field strength map. In addition, the initial state of the target’s depth is estimated by the full width at half maximum (FWHM) method. In addition, the initial state of the magnetic polarizability tensor is estimated by the least squares method. Then, these initial states are used as the initial values for KF and EKF. Finally, the position, posture and polarizability of the target are recursively calculated. A simulation platform for the underground metal detection is built in this paper. The simulation results show that the initial value estimation method proposed for the filtering algorithm has an excellent performance in the underground metal detection.

scholarly journals Four-Element Microstrip Patch Array Antenna with Corporate-Series Feed Network for 5G Communication

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Janam Maharjan ◽  
Dong-You Choi
Keyword(s):  
Microstrip Antennas ◽  
Array Antenna ◽  
Frequency Bandwidth ◽  
Microstrip Patch ◽  
Feeding Technique ◽  
Feed Network ◽  
Overall Performance ◽  
5G Communication ◽  
Element Array ◽  
Series Technique

The paper proposes a simple four-element microstrip patch array antenna fed with corporate-series technique. The paper compares the proposed design with four-element antennas fed with only series-fed and corporate-fed microstrip antennas. All three antenna designs use rectangular microstrip patch elements with two insets and slots on both sides of the patch. The patch elements are accompanied by Yagi elements: three director elements and two reflector elements. Through comparison of simulation results, the paper shows that four-element array antenna with combined corporate-series feeding technique performs better compared to antennas with only either series or corporate feeding network. The proposed corporate-series fed antenna achieves better performance with wide frequency bandwidth of 25.04–30.87 GHz and gain of 9.5 dB. The antenna has an end-fire radiation pattern. Overall performance shows that the proposed corporate-series-fed microstrip patch antenna with Yagi elements is suitable for next generation 5G communication.

scholarly journals Performance Analysis for Cooperative Communication System with QC-LDPC Codes Constructed with Integer Sequences

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yan Zhang ◽  
Feng-fan Yang ◽  
Weijun Song
Keyword(s):  
Cooperative Communication ◽  
Ldpc Codes ◽  
Ldpc Code ◽  
Parity Check ◽  
Integer Sequences ◽  
Excellent Performance ◽  
Array Codes ◽  
Integer Sequence ◽  
Overall Performance ◽  
Better Than

This paper presents four different integer sequences to construct quasi-cyclic low-density parity-check (QC-LDPC) codes with mathematical theory. The paper introduces the procedure of the coding principle and coding. Four different integer sequences constructing QC-LDPC code are compared with LDPC codes by using PEG algorithm, array codes, and the Mackey codes, respectively. Then, the integer sequence QC-LDPC codes are used in coded cooperative communication. Simulation results show that the integer sequence constructed QC-LDPC codes are effective, and overall performance is better than that of other types of LDPC codes in the coded cooperative communication. The performance of Dayan integer sequence constructed QC-LDPC is the most excellent performance.

scholarly journals Compatibilization and Toughening of Biodegradable Poly (Lactic Acid) / Cellulose Acetate Films by Polyamide Amine Dendrimers

2021 ◽  
Author(s):  
Yansong Huang ◽  
Yu juan Jin ◽  
Bo Wang ◽  
Huafeng Tian ◽  
Yunxuan Weng ◽  
...  
Keyword(s):  
Cellulose Acetate ◽  
Oxygen Permeability ◽  
Pamam Dendrimer ◽  
Poly Lactic Acid ◽  
Test Results ◽  
Excellent Performance ◽  
Blend Films ◽  
Biodegradable Poly ◽  
Green Packaging ◽  
Overall Performance

Abstract Due to the poor compatibility caused by the large difference in hydrophilicity and interface between polylactic acid (PLA) and cellulose acetate (CA), the blending of the two materials is difficult and the application is limited. To solve this problem, a type of polyamide amine (PAMAM) dendrimer was introduced to modify PLA / CA blends in this work. The results showed that PAMAM could improve the compatibility of PLA / CA blends, promote the distribution of CA and crystallization of PLA. At the same time, adding PAMAM could enhance the mechanical properties of the blend material, and the toughness and tear strength were increased by 551% and 141%, respectively. In addition, the incorporation of PAMAM increased hydrophobicity and oxygen permeability of PLA/ CA blends, and the oxygen permeability could be increased by up to 3 orders of magnitude. Degradation test results showed that the blend exhibited good biodegradability. The overall performance of the PLA/ CA blend film was optimal when the content of PAMAM was 3 phr. The biodegradable blend films with excellent performance provided wide application prospect in the food green packaging fields.

Self-Assembled Nano-Composite Perovskites as Highly Efficient and Robust Hybrid Cathode for Solid Oxide Fuel Cell

2021 ◽  
Author(s):  
Jun Hyuk Kim ◽  
Kyuseon Jang ◽  
Dae-Kwang Lim ◽  
Sejong Ahn ◽  
DongHwan Oh ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Oxygen Reduction Reaction ◽  
Solid Oxide Fuel Cell ◽  
Oxygen Reduction ◽  
Single Phase ◽  
Reduction Reaction ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Nano Composite ◽  
Overall Performance

Oxygen reduction reaction, which proceeds at the cathode of a fuel cell, is primarily important as its rate determines the overall performance of the device. However, designing a single-phase material...

Singe-Phase Grid-Connected Inverter Based on Voltage-Oriented Control in Photovoltaic Generation Systems

2013 ◽  
Vol 765-767 ◽  
pp. 2498-2502
Author(s):  
Yong Yang ◽  
Chun Qing Qi ◽  
Ji Suo ◽  
Feng Wen Cao
Keyword(s):  
Feedback Control ◽  
Reference Frame ◽  
Single Phase ◽  
Control Structure ◽  
Current Control ◽  
Control Loop ◽  
Excellent Performance ◽  
Photovoltaic Generation ◽  
Control Scheme ◽  
Grid Connected Inverter

The paper proposes a new control of a transformerless singe-stage single-phase grid-connected inverter in photovoltaic generation systems. The control scheme is mainly based on voltage-oriented control (VOC) with help of second order Generalized Integrator (SOGI). A cascaded control structure with an outer dc link voltage control loop and an inner current control loop is used. The currents are controlled in a synchronous dq reference frame using a decoupled feedback control. The simulated results have proven an excellent performance and verified the validity of proposed system.

In-Flight Navigation Using Head-Coupled and Aircraft-Coupled Spatial Audio Cues

2007 ◽  
Vol 51 (19) ◽  
pp. 1341-1344 ◽  
Author(s):  
Brian D. Simpson ◽  
Douglas S. Brungart ◽  
Ronald C. Dallman ◽  
Richard J. Yasky ◽  
Griffin D. Romigh ◽  
...  
Keyword(s):  
Flight Test ◽  
Frame Of Reference ◽  
General Aviation ◽  
Spatial Audio ◽  
Excellent Performance ◽  
Audio Cues ◽  
Overall Performance ◽  
General Aviation Aircraft ◽  
Spatialized Audio

A flight test was conducted to evaluate how effectively spatialized audio cues could be used to maneuver a general aviation aircraft through a complex navigation course. Two conditions were tested: a head-coupled condition, where audio cues were updated in response to changes in the orientation of the pilot's head, and an aircraft-coupled condition, where audio cues were updated in response to changes in the direction of the aircraft. Both cueing conditions resulted in excellent performance, with the pilots on average passing within 0.25 nm of the waypoints on the navigation course. However, overall performance was better in the aircraft-coupled condition than in the head-coupled condition. This result is discussed in terms of an alignment mismatch between the pilot's frame of reference and that of the aircraft, which is critical when using spatial audio to cue the desired orientation of the vehicle rather than the location of an object in space.

scholarly journals 5G Mobile Communication Development Trend and Several Key Technologies

2018 ◽  
Vol 246 ◽  
pp. 03034
Author(s):  
Liping Zheng
Keyword(s):  
Mobile Communication ◽  
Communication System ◽  
Development Trend ◽  
Practical Application ◽  
Application Process ◽  
Theoretical Support ◽  
Key Technologies ◽  
Great Progress ◽  
Overall Performance ◽  
5G Mobile Communication

The overall performance of 5G mobile communication network has made great progress compared with 4G network. In order to ensure the expected utility of 5G communication system in practical application, this paper will focus on the future development trend of this communication system and its research on key technologies involved in the application process to provide theoretical support to relevant practitioners.

Sign in / Sign up

Export Citation Format

Share Document