A new recursive algorithm with the partial parallel structure based on the linearly constrained minimum variance(LCMV)criterion for adaptive monopulse systems is proposed.The weight vector associated with the original...A new recursive algorithm with the partial parallel structure based on the linearly constrained minimum variance(LCMV)criterion for adaptive monopulse systems is proposed.The weight vector associated with the original whole antenna array is decomposed into several adaptive weight sub-vectors firstly.An adaptive algorithm based on the conventional LCMV principle is then deduced to update the weight sub-vectors for sum and difference beam,respectively.The optimal weight vector can be obtained after convergence.The required computational complexity is evaluated for the proposed technique,which is on the order of O(N)and less than that of the conventional LCMV method.The flow chart scheme with the partial parallel structure of the proposed algorithm is introduced.This scheme is easy to be implemented on a distributed computer/digital signal processor(DSP)system to solve the problems of the heavy computational burden and vast data transmission of the large-scale adaptive monopulse array.Then,the monopulse ratio and convergence rate of the proposed algorithm are evaluated by numerical simulations.Compared with some recent adaptive monopulse estimation methods,a better performance on computational complexity and monopulse ratio can be achieved with the proposed adaptive method.展开更多
By applying phase-only technique in array antenna pattern synthesis, antenna arrays can form desired patterns with the use of phase shifters only. A novel phase-only pattern synthesis algorithm is proposed for the pas...By applying phase-only technique in array antenna pattern synthesis, antenna arrays can form desired patterns with the use of phase shifters only. A novel phase-only pattern synthesis algorithm is proposed for the passive phased array seeker. This algorithm synthesizes the main beam of the antenna pattern through least-squares approximation, thus minimizing the errors between the actual and the desired main beams. The synthesis problem can be solved by applying gradient-descent optimization. The item for suppressing side lobes is added to the above synthesis problem. To obtain a side lobe level as low as possible, the algorithm assigns different weights to different directions in the side lobe region. The algorithm is run repeatedly and the weights are adjusted adaptively according to the normalized power in the side lobe directions. Detailed examples are presented to demonstrate the accuracy and effectiveness of the proposed approach.展开更多
A power amplifier’s linearity determines the emission signal’s quality and the efficiency of the system.Nonlinear distortion can result in system bit error,out-of-band radiation,and interference with other channels,...A power amplifier’s linearity determines the emission signal’s quality and the efficiency of the system.Nonlinear distortion can result in system bit error,out-of-band radiation,and interference with other channels,which severely influence communication system’s quality and reliability.Starting from the third-order intermodulation point of the milimeter wave(mm-Wave)power amplifiers,the circuit’s nonlinearity is compensated for.The analysis,design,and implementation of linear class AB mm-Wave power amplifiers based on GlobalFoundries 45 nm CMOS silicon-on-insulator(SOI)technology are presented.Three single-ended and differential stacked power amplifiers have been implemented based on cascode cells and triple cascode cells operating in U-band frequencies.According to nonlinear analysis and on-wafer measurements,designs based on triple cascode cells outperform those based on cascode cells.Using single-ended measurements,the differential power amplifier achieves a measured peak power-added efficiency(PAE)of 47.2%and a saturated output power(P_(sat))of 25.2 dBm at 44 GHz.The amplifier achieves a P_(sat)higher than 23 dBm and a maximum PAE higher than 25%in the measured bandwidth from 44 GHz to 50 GHz.展开更多
基金supported by the National Natural Science Foundation of China(11273017)
文摘A new recursive algorithm with the partial parallel structure based on the linearly constrained minimum variance(LCMV)criterion for adaptive monopulse systems is proposed.The weight vector associated with the original whole antenna array is decomposed into several adaptive weight sub-vectors firstly.An adaptive algorithm based on the conventional LCMV principle is then deduced to update the weight sub-vectors for sum and difference beam,respectively.The optimal weight vector can be obtained after convergence.The required computational complexity is evaluated for the proposed technique,which is on the order of O(N)and less than that of the conventional LCMV method.The flow chart scheme with the partial parallel structure of the proposed algorithm is introduced.This scheme is easy to be implemented on a distributed computer/digital signal processor(DSP)system to solve the problems of the heavy computational burden and vast data transmission of the large-scale adaptive monopulse array.Then,the monopulse ratio and convergence rate of the proposed algorithm are evaluated by numerical simulations.Compared with some recent adaptive monopulse estimation methods,a better performance on computational complexity and monopulse ratio can be achieved with the proposed adaptive method.
基金supported by the National Natural Science Foundation of China(1127301761401207+2 种基金6147119661501240)the College Graduate Scientific Research Innovation Fund in Jiangsu Province of China(KYLX16_0447)
基金supported by the National Natural Science Foundation of China(1127301761471196)
文摘By applying phase-only technique in array antenna pattern synthesis, antenna arrays can form desired patterns with the use of phase shifters only. A novel phase-only pattern synthesis algorithm is proposed for the passive phased array seeker. This algorithm synthesizes the main beam of the antenna pattern through least-squares approximation, thus minimizing the errors between the actual and the desired main beams. The synthesis problem can be solved by applying gradient-descent optimization. The item for suppressing side lobes is added to the above synthesis problem. To obtain a side lobe level as low as possible, the algorithm assigns different weights to different directions in the side lobe region. The algorithm is run repeatedly and the weights are adjusted adaptively according to the normalized power in the side lobe directions. Detailed examples are presented to demonstrate the accuracy and effectiveness of the proposed approach.
基金Project supported by the National Natural Science Foundation of China(No.62001232)。
文摘A power amplifier’s linearity determines the emission signal’s quality and the efficiency of the system.Nonlinear distortion can result in system bit error,out-of-band radiation,and interference with other channels,which severely influence communication system’s quality and reliability.Starting from the third-order intermodulation point of the milimeter wave(mm-Wave)power amplifiers,the circuit’s nonlinearity is compensated for.The analysis,design,and implementation of linear class AB mm-Wave power amplifiers based on GlobalFoundries 45 nm CMOS silicon-on-insulator(SOI)technology are presented.Three single-ended and differential stacked power amplifiers have been implemented based on cascode cells and triple cascode cells operating in U-band frequencies.According to nonlinear analysis and on-wafer measurements,designs based on triple cascode cells outperform those based on cascode cells.Using single-ended measurements,the differential power amplifier achieves a measured peak power-added efficiency(PAE)of 47.2%and a saturated output power(P_(sat))of 25.2 dBm at 44 GHz.The amplifier achieves a P_(sat)higher than 23 dBm and a maximum PAE higher than 25%in the measured bandwidth from 44 GHz to 50 GHz.
