In this article, a new low-profile decoupling structure originated from the phase shift concept for the patch antenna array is proposed. To clearly illustrate the operation principle, the phase of ...the signal transmitted from Patch 1 to Patch 2 has been initially studied and the decoupling condition for two closely spaced patch antennas in H-plane has also been obtained. Afterward, the decoupling element concisely composed of a half-wave microstrip line and a shorting pin is developed. Attributing to the introduction of additional signal path by the new decoupling structure, mutual coupling between two adjacent patches is effectively suppressed. To verify the feasibility of the proposed design scheme, demonstrators of two-element patch antennas with and without decoupling structure are, respectively, implemented and analyzed. Results indicate that compared with the coupled array, the isolation between two patch elements is enhanced from 7 to 18 dB at the center frequency of 3.16 GHz under the edge-to-edge separation of only 0.027 <inline-formula> <tex-math notation="LaTeX">\lambda _{0} </tex-math></inline-formula>. Besides, owing to the single layer layout, the profile of the whole antenna structure is as low as 0.02 <inline-formula> <tex-math notation="LaTeX">\lambda _{0} </tex-math></inline-formula>. Ultimately, the proposed decoupling scheme has been applied to the three-element counterpart, so as to demonstrate and validate its effeteness of isolation enhancement for multielement patch array.
This paper combines the piecewise Cubic Hermite (CH) interpolation algorithm and the weighted least square support vector machine (WLS-SVM) to improve identification accuracy for marine crafts built ...based on the characteristic model. The characteristic model is first used to describe the heading dynamics of marine crafts and is a superior model to the traditional response model in both accuracy and complexity. Especially in order to improve identification accuracy, a CH-based data preprocessing strategy is utilized to densify and smooth data for further accurate identification. Subsequently, the combination of the linear kernel function and the Gaussian kernel function is introduced in the conventional WLS-SVM method, which renders global and local performance improvements compared with the conventional WLS-SVM method. Finally, informative maneuvers composed of Zigzag and Sine are carried out to test the performance of the improved identification method. Compared to the conventional LS-SVM method based on the response model, the root mean square error of the proposed CH-MK-WLS-SVM method based on the characteristic model is reduced by an order of magnitude in the presence of sensor noise.
In this paper, multiband antennas based on a single ring slot are proposed for 4G/5G smartphone applications. The basic structure of the antenna is consisted of a large metal ground and an unbroken ...metal rim, in which a single 2 mm-wide ring slots is realized between the metal ground and rim. Here, a reconfigurable 4G antenna (820-960 and 1710-2690 MHz) is initially devised by loading multiple grounded stubs and a simple dc controlling circuit with varactor diode into the upper section of the ring slot. To further cover the sub-6 GHz spectrum (3400-3600 MHz) for future 5G communications, a four-element multi-input multi-output (MIMO) slot antennas configuration is designed by utilizing the lower section of the ring slot. A prototype antenna was fabricated, and good agreement is shown between the measured and simulated results. Due to the advantages such as multiband operation, MIMO configuration for 5G communications, high isolation, and compact structure, the proposed antenna design is attractive for 4G/5G smartphones.
Online dynamic model identification is a promising technology for designing the model-based controller of marine crafts. This study confronts the online model identification and maneuvering ...prediction for marine crafts with an adaptive event-triggered mechanism. In particular, the least square-twin support vector machines algorithm is exploited to identify the dynamic model accurately. Meanwhile, an online adaptive event-triggered identification and prediction framework is proposed to deal with the issue of when to update the dynamic model. Finally, a comparative analysis of the identification and prediction performance between the proposed framework and the non-updated model method is performed. The former superiority is highlighted by experiments based on a marine craft, which shows that it reduces the root mean square error of the yaw rate by up to 45.9%. Thereby, the proposed online identification framework offers great potential for future practical applications of marine crafts.
•An adaptive event-triggered mechanism is proposed for online model identification.•The threshold of the event-triggered mechanism is adaptively adjusted, which is flexible in practice.•The proposed framework is verified by experiments based on a marine craft.
A novel approach for maneuvering prediction of marine crafts in data-limited situations is presented in this study. The approach is a hybrid strategy that combines least square-support vector ...machines (LS-SVM) and a self-error corrector that integrates K-means clustering with Markov model. The strategy allows testing errors caused by LS-SVM to be compensated effectively by the dedicated self-error corrector. To classify the inputs of the Markov model-based error corrector rapidly and properly, the K-means clustering algorithm is resorted to classifying the training errors obtained from LS-SVM. Assuming that maneuvering prediction for marine crafts with a limited number of simulation or experiment data, a comparative analysis of the prediction performance between the proposed strategy and the conventional method based on LS-SVM is performed. The results of numerical simulations and experiments demonstrate the superiority of the proposed strategy, which reduces the root mean square error of surge speed by up to 86.2% in simulation tests and 54.5% in experiments.
•A novel hybrid maneuver prediction strategy for data-limited marine crafts is proposed.•The strategy includes a self-error corrector integrating K-means clustering with Markov model.•The dedicated self-error corrector can well predict and compensate the testing errors of LS-SVM.•The K-means algorithm quickly classifies LS-SVM training errors in the self-error corrector.
In this paper, dedicated to maneuvering prediction for marine crafts with a limited amount of data, a Twin LS-SVM-based error-compensated maneuvering prediction strategy for the parametric model is ...presented. The strategy used one LS-SVM to pre-predict marine craft motion and obtain training data errors. Another LS-SVM is designed for the prediction and compensation of testing errors generated by the former LS-SVM. The new strategy can render accurate and robust prediction improvements in data-limited situations. Then, a comparative analysis of prediction performance between the Twin LS-SVM strategy and the conventional method based on LS-SVM is contributed to demonstrate the effectiveness of the proposed strategy. Both simulation test results and experimental study results indicate that the developed strategy is a powerful and practical prediction tool for marine crafts, which shows that it reduces the root mean square error of speeds by up to 64.7% in simulation tests, and 49.2% in experiments.
In this paper, an adaptive anti-noise least-squares algorithm (ANLS) is proposed for parameter identification of an unmanned marine vehicle in the presence of measurement noise. As a basis, a ...horizontal-plane second-order nonlinear Nomoto model is established and transformed into a discrete-time model for parameter identification. Then, a noise reduction term is added to the loss function to achieve a trade-off between the anti-noise effect and parameter identification accuracy. Furthermore, the Levenberg–Marquardt algorithm is embedded into the parameter identification algorithm to achieve adaptive coefficient optimization. Finally, the simulation and experimental data are utilized for parameter identification and performance validation. By comparing with the recursive least-squares algorithm and least-squares support vector machine algorithm, the excellent anti-noise and maneuvering prediction abilities of the proposed ANLS algorithm are verified, i.e., up to 84% reduction of the identification error in the simulation and less than
4
∘
of the heading angle prediction error in the experiment.
In this article, a new design of a wideband dual-polarized (DP) single-layered differential fed dipole antenna with low profile based on square patch resonator is presented. The proposed antenna is ...composed of a square patch resonator and two polarization channels consisting of dipole antennas. By virtue of TM12- and TM21-mode, the feasibility of excitation of planar dipole antennas and intrinsic polarization isolation can be conceived. Thus, a DP differential fed planar dipole antenna prototype is developed. To further enhance the gain level, extra reflectors are introduced, and significant improvement of gain is achieved as expected. For validation, the proposed DP dipole antenna is simulated. The simulated results exhibit excellent performances in terms of a 10-dB impedance bandwidth of 8.6% from 3.4 to 3.71 GHz, a stable in-band gain of 7.6 dBi, a high channel isolation of over 55 dB and a low profile of 0.015λ0.
A Novel E-plane MIMO Patch Antenna Using Compact Decoupling Method Pei, Tianqi; Wang, Jianpeng; Zhu, Lei ...
2022 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP),
2022-Nov.-27
Conference Proceeding
In this article, a neoteric compact decoupling technique that is inspired by the capacitive and inductive coupling concept has been proposed for the MIMO patch antenna in E-plane. The original strong ...coupling can be effectively suppressed by a pair of identical decoupling structures made up of a transmission line of a half wavelength and a shorting pin. In order to demonstrate this operation concept clearly, the original signal path through has been initially studied, especially for its phase shifting. Then, the decoupling requirement has been determined. Two-unit coupled and decoupled patch antennas have been examined in order to demonstrate the desired design concept. Results show that the measured resonant frequency is centered at 4.85 GHz with the isolation between two decoupled patch antennas increased from 8.5dB to 20dB in comparison to the coupled one. The edge-to-edge space fof the proposed study is only 0.044λ 0 which has negligible impact on the radiation properties.
