In this paper,an integrated substrate gap waveguide(ISGW)filtering antenna is proposed at millimeter wave band,whose surface wave and spurious modes are simultaneously suppressed.A secondorder filtering response is ob...In this paper,an integrated substrate gap waveguide(ISGW)filtering antenna is proposed at millimeter wave band,whose surface wave and spurious modes are simultaneously suppressed.A secondorder filtering response is obtained through a coupling feeding scheme using one uniform impedance resonator(UIR)and two stepped-impedance resonators(SIRs).To increase the stopband width of the antenna,the spurious modes are suppressed by selecting the appropriate sizes of the ISGW unit cell.Furthermore,the ISGW is implemented to improve the radiation performance of the antenna by alleviating the propagation of surface wave.And an equivalent circuit is investigated to reveal the working principle of ISGW.To demonstrate this methodology,an ISGW filtering antenna operating at a center frequency of 25 GHz is designed,fabricated,and measured.The results show that the antenna achieves a stopband width of 1.6f0(center frequency),an out-of-band suppression level of 21 dB,and a peak realized gain of 8.5 dBi.展开更多
Compact fifth-generation(5G)low-frequency band filtering antennas(filtennas)with stable directive radiation patterns,improved bandwidth(BW),and gain are designed,fabricated,and tested in this research.The proposed fil...Compact fifth-generation(5G)low-frequency band filtering antennas(filtennas)with stable directive radiation patterns,improved bandwidth(BW),and gain are designed,fabricated,and tested in this research.The proposed filtennas are achieved by combining the predesigned compact 5G(5.975–7.125 GHz)third-order uniform and non-uniform transmission line hairpin bandpass filters(UTL and NTL HPBFs)with the compact ultrawide band Vivaldi tapered slot antenna(UWB VTSA)in one module.The objective of this integration is to enhance the performance of 5.975–7.125GHz filtennas which will be suitable for modern mobile communication applications by exploiting the benefits of UWB VTSA.Based on NTL HPBF,more space is provided to add the direct current(DC)biassing circuits in cognitive radio networks(CRNs)for frequency reconfigurable applications.To overcome the mismatch between HPBFs and VTSA,detailed parametric studies are presented.Computer simulation technology(CST)software is used for the simulation in this study.Good measured S11 appeared to be<−13 and<−10.54 dB at 5.48–7.73 and 5.9–7.98GHz with peak realized gains of 6.37 and 6.27 dBi,for VTSA with UTL and NTL HPBFs,respectively which outperforms the predesigned filters.Validation is carried out by comparing the measured and simulated results.展开更多
Adaptive control algorithm ls a key technlque for an adaptive array. It ls necessary to find a fastand efficient aIgorithm ror gaining rapid interrerence suppression. Convergence speed of conventional gradient-based a...Adaptive control algorithm ls a key technlque for an adaptive array. It ls necessary to find a fastand efficient aIgorithm ror gaining rapid interrerence suppression. Convergence speed of conventional gradient-based algoritkms ls extremely slow and very sensitive to elgenvalue spread of autocorrelation matrix. Thispaper presents the Kalman filtering method to adaptlve array processing. It has good transient response andachieves faster convergence speed,so it is msot su1table for complicated adaptive systems. We analyzed itsconvergence performance which proved to be related to initial value for P(0). Computer simulation by applying four elements array to null steering was carrled out. It ls shown that fast convergence needs only 2Mnumbers of iteration. The Iess the value was seIected for P(o),the slower convergence was found. Further,ifP(o) were too, small, the method would not be abIe to converge. On the other hand, bigger values of P(0)can not achieve more lmprovement in convergence per formance. Slmulation aIso discovered steady responsedenoted with SNIR dependent on the power of reference signai. These results demonstrate the validity and effectiveness 0f the Kalman type adaptlve antenna.展开更多
The filter and antenna are two key components of the radio frequency(RF)front-end.When the antenna is directly connected with the filter,additional mismatch losses will be caused.Therefore,the antenna and filter are i...The filter and antenna are two key components of the radio frequency(RF)front-end.When the antenna is directly connected with the filter,additional mismatch losses will be caused.Therefore,the antenna and filter are integrated into a single device to provide both filtering and radiating functions.In this way,many advantages,like low cost,light weight,small size and lower insertion loss can be obtained.In this paper,the co-design approaches of RF filter-antenna are reviewed.Based on the open literatures,the integrated approaches of filtering antenna can be classified into five main categories:1)Co-design by optimizing the interfacing impedance,2)co-design according to the synthesis approach of filter,3)co-design by embedding novel resonators within the feeding structures,4)co-design by employing auxiliary physical structures,and 5)other methods.The RF filter-antenna system can improve the integration degree of RF frontend,reduce its size and cost,and optimize its performance.展开更多
The principle and performance of Synthetic Impulse and Antenna Radar(SIAR) are analyzed with the concept of 3D matched filtering. The discussion here is concentrated on the characteristics of SIAR in the case of three...The principle and performance of Synthetic Impulse and Antenna Radar(SIAR) are analyzed with the concept of 3D matched filtering. The discussion here is concentrated on the characteristics of SIAR in the case of three dimensions. The results obtained are helpful for designing this new style radar.展开更多
The adaptive array antenna may be considered as a general sidelobe canceller. Directional interference suppression is based on a recursive state estimation of Kalman filter. For the stationary filter,this leads to an...The adaptive array antenna may be considered as a general sidelobe canceller. Directional interference suppression is based on a recursive state estimation of Kalman filter. For the stationary filter,this leads to an iterative solution of Wiener Hops matrix equation. The performance of sidelobe canceller are studied by computer simulation. The result of simulation shows that the sidelobe canceller may be regarded as a special case of an adaptive array atenna.展开更多
This paper proposes an estimation method of the directions of arrival(DOA) for the broadband signals received by a uniform planar antenna array including the mutual coupling effect. The process modeling of antenna arr...This paper proposes an estimation method of the directions of arrival(DOA) for the broadband signals received by a uniform planar antenna array including the mutual coupling effect. The process modeling of antenna array receiving dynamic signal is obtained accurately via building the array system electromagnetic space-time model, and the mutual coupling effect is included in the synthesis procedure automatically. The broadband signal is divided into several sub-bands, and the complex weight of these sub-bands frequencies is figured out using the least mean square iteration programming. In the proposed method, the mutual coupling effect is compensated at the different frequencies. The calculation results show that the method is suitable for the uniform linear and uniform circular array pattern integration, and it is commendably satisfied with the requirement of engineering design.展开更多
We address the problem of interference as related to Satellite Personal Communication Networks (S-PCNs). Basic low Earth orbit (LEO) constellation is considered. The paper uses combined adaptive antenna arrays and ada...We address the problem of interference as related to Satellite Personal Communication Networks (S-PCNs). Basic low Earth orbit (LEO) constellation is considered. The paper uses combined adaptive antenna arrays and adaptive filtering technique. This hybrid linear adaptive technique provides improved performance eliminating interference, particularly uncorrelated signals residing in the antenna sidelobes.展开更多
Detecting target echo in the existence of self-screen jamming is a challenging work for radar system, especially when digital radio frequency memory(DRFM) technique is employed that mixes the jamming and target echo b...Detecting target echo in the existence of self-screen jamming is a challenging work for radar system, especially when digital radio frequency memory(DRFM) technique is employed that mixes the jamming and target echo both in spatial and time-frequency domain. The conventional way to solve this problem would suffer from performance degradation when physical target(PT) and false target(FT) are superposed in time. In this paper, we propose a new spatial filter according to the different correlation characteristic between PT and FT. The filter takes the ratio of expected signal power to expected jamming and noise power as the objective function under the constant filter modulus constraint. The optimal filter coefficients are derived with a generalized rayleigh quotient approach. Moreover, we analytically compute the target detection probability and demonstrate the applicability of the proposed method to the correlation coefficient. Monte Carlo simulations are provided to corroborate the proposed studies. Furthermore, the proposed method has simple architecture and low computation complexity, making it easily applied in modern radar system.展开更多
基金This work was supported by the National Key research and development program of China(No.2021YFB 2900401)the national natural science foundation of China(No.62361057,No.61861046)+1 种基金the key natural science foundation of Shenzhen(No.JCYJ20220818102209020)the key research and development program of Shenzhen(No.ZDSYS20210623091807023).
文摘In this paper,an integrated substrate gap waveguide(ISGW)filtering antenna is proposed at millimeter wave band,whose surface wave and spurious modes are simultaneously suppressed.A secondorder filtering response is obtained through a coupling feeding scheme using one uniform impedance resonator(UIR)and two stepped-impedance resonators(SIRs).To increase the stopband width of the antenna,the spurious modes are suppressed by selecting the appropriate sizes of the ISGW unit cell.Furthermore,the ISGW is implemented to improve the radiation performance of the antenna by alleviating the propagation of surface wave.And an equivalent circuit is investigated to reveal the working principle of ISGW.To demonstrate this methodology,an ISGW filtering antenna operating at a center frequency of 25 GHz is designed,fabricated,and measured.The results show that the antenna achieves a stopband width of 1.6f0(center frequency),an out-of-band suppression level of 21 dB,and a peak realized gain of 8.5 dBi.
基金This work was supported by the Postdoctoral Fellowship Scheme under the Professional Development Research University from Universiti Teknologi Malaysia(UTM)under Grant 06E07.
文摘Compact fifth-generation(5G)low-frequency band filtering antennas(filtennas)with stable directive radiation patterns,improved bandwidth(BW),and gain are designed,fabricated,and tested in this research.The proposed filtennas are achieved by combining the predesigned compact 5G(5.975–7.125 GHz)third-order uniform and non-uniform transmission line hairpin bandpass filters(UTL and NTL HPBFs)with the compact ultrawide band Vivaldi tapered slot antenna(UWB VTSA)in one module.The objective of this integration is to enhance the performance of 5.975–7.125GHz filtennas which will be suitable for modern mobile communication applications by exploiting the benefits of UWB VTSA.Based on NTL HPBF,more space is provided to add the direct current(DC)biassing circuits in cognitive radio networks(CRNs)for frequency reconfigurable applications.To overcome the mismatch between HPBFs and VTSA,detailed parametric studies are presented.Computer simulation technology(CST)software is used for the simulation in this study.Good measured S11 appeared to be<−13 and<−10.54 dB at 5.48–7.73 and 5.9–7.98GHz with peak realized gains of 6.37 and 6.27 dBi,for VTSA with UTL and NTL HPBFs,respectively which outperforms the predesigned filters.Validation is carried out by comparing the measured and simulated results.
文摘Adaptive control algorithm ls a key technlque for an adaptive array. It ls necessary to find a fastand efficient aIgorithm ror gaining rapid interrerence suppression. Convergence speed of conventional gradient-based algoritkms ls extremely slow and very sensitive to elgenvalue spread of autocorrelation matrix. Thispaper presents the Kalman filtering method to adaptlve array processing. It has good transient response andachieves faster convergence speed,so it is msot su1table for complicated adaptive systems. We analyzed itsconvergence performance which proved to be related to initial value for P(0). Computer simulation by applying four elements array to null steering was carrled out. It ls shown that fast convergence needs only 2Mnumbers of iteration. The Iess the value was seIected for P(o),the slower convergence was found. Further,ifP(o) were too, small, the method would not be abIe to converge. On the other hand, bigger values of P(0)can not achieve more lmprovement in convergence per formance. Slmulation aIso discovered steady responsedenoted with SNIR dependent on the power of reference signai. These results demonstrate the validity and effectiveness 0f the Kalman type adaptlve antenna.
基金supported by the National Science Foundation of China under Grant No.61771295the Natural Science Young Foundation of Shanxi Province under Grant Nos.2014021021-1 and 2015011042
文摘The filter and antenna are two key components of the radio frequency(RF)front-end.When the antenna is directly connected with the filter,additional mismatch losses will be caused.Therefore,the antenna and filter are integrated into a single device to provide both filtering and radiating functions.In this way,many advantages,like low cost,light weight,small size and lower insertion loss can be obtained.In this paper,the co-design approaches of RF filter-antenna are reviewed.Based on the open literatures,the integrated approaches of filtering antenna can be classified into five main categories:1)Co-design by optimizing the interfacing impedance,2)co-design according to the synthesis approach of filter,3)co-design by embedding novel resonators within the feeding structures,4)co-design by employing auxiliary physical structures,and 5)other methods.The RF filter-antenna system can improve the integration degree of RF frontend,reduce its size and cost,and optimize its performance.
文摘The principle and performance of Synthetic Impulse and Antenna Radar(SIAR) are analyzed with the concept of 3D matched filtering. The discussion here is concentrated on the characteristics of SIAR in the case of three dimensions. The results obtained are helpful for designing this new style radar.
文摘The adaptive array antenna may be considered as a general sidelobe canceller. Directional interference suppression is based on a recursive state estimation of Kalman filter. For the stationary filter,this leads to an iterative solution of Wiener Hops matrix equation. The performance of sidelobe canceller are studied by computer simulation. The result of simulation shows that the sidelobe canceller may be regarded as a special case of an adaptive array atenna.
基金supported by the Chinese Natural Science Foundation (61401075)
文摘This paper proposes an estimation method of the directions of arrival(DOA) for the broadband signals received by a uniform planar antenna array including the mutual coupling effect. The process modeling of antenna array receiving dynamic signal is obtained accurately via building the array system electromagnetic space-time model, and the mutual coupling effect is included in the synthesis procedure automatically. The broadband signal is divided into several sub-bands, and the complex weight of these sub-bands frequencies is figured out using the least mean square iteration programming. In the proposed method, the mutual coupling effect is compensated at the different frequencies. The calculation results show that the method is suitable for the uniform linear and uniform circular array pattern integration, and it is commendably satisfied with the requirement of engineering design.
文摘We address the problem of interference as related to Satellite Personal Communication Networks (S-PCNs). Basic low Earth orbit (LEO) constellation is considered. The paper uses combined adaptive antenna arrays and adaptive filtering technique. This hybrid linear adaptive technique provides improved performance eliminating interference, particularly uncorrelated signals residing in the antenna sidelobes.
文摘Detecting target echo in the existence of self-screen jamming is a challenging work for radar system, especially when digital radio frequency memory(DRFM) technique is employed that mixes the jamming and target echo both in spatial and time-frequency domain. The conventional way to solve this problem would suffer from performance degradation when physical target(PT) and false target(FT) are superposed in time. In this paper, we propose a new spatial filter according to the different correlation characteristic between PT and FT. The filter takes the ratio of expected signal power to expected jamming and noise power as the objective function under the constant filter modulus constraint. The optimal filter coefficients are derived with a generalized rayleigh quotient approach. Moreover, we analytically compute the target detection probability and demonstrate the applicability of the proposed method to the correlation coefficient. Monte Carlo simulations are provided to corroborate the proposed studies. Furthermore, the proposed method has simple architecture and low computation complexity, making it easily applied in modern radar system.