摘要 :
To determine the most appropriate design for ultra wideband (UWB) receiver front-end, a study was conducted on the designs of wideband antennas, wideband filters, and wideband amplifiers. Previous works on these devices have been ...
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To determine the most appropriate design for ultra wideband (UWB) receiver front-end, a study was conducted on the designs of wideband antennas, wideband filters, and wideband amplifiers. Previous works on these devices have been analysed and compared for the following major parameters, which are antenna return loss, antenna bandwidth, filter bandwidth, filter insertion loss, filter return loss, amplifier gain, amplifier bandwidth, amplifier return loss, and amplifier noise figure. This work is to integrate wideband antenna, filter, and amplifier that were previously designed separately, into a complete UWB receiver front-end. The preferred designs for the integration are antipodal Vivaldi for the antenna, multiple-mode resonator (MMR) for the filter, and three cascaded Agilent HMMC-5200 series-shunt heterojunction bipolar transistor (HBT) amplifiers for the amplifier module. Setup and simulation of the antenna is performed using Agilent ADS Momentum while the simulations of the filter and UWB amplifier module are performed using Agilent ADS Schematic. The antipodal Vivaldi antenna achieves partial wideband capability with return loss below -10 dB between 3.3 GHz and 6.2 GHz. The MMR bandpass filter simulation realizes an almost maximally flat insertion loss response for the entire UWB passband that is from 3.1 GHz to 10.6 GHz and return loss below -15 dB throughout the passband. The UWB amplifier module demonstrates amplification from 28.7 dB to 30.3 dB and return loss below -17 dB from DC to 20 GHz. The front-end simulation realizes 25 dB to 29 dB of signal amplification within the UWB passband. The out-of-band rejection performances are 8.2 dB/GHz and -8.1 dB/GHz roll-off rates for the lower and upper stopband respectively. The link system also realizes low noise figure between 1.47 dB and 3.13 dB within the UWB passband.
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摘要 :
A strategy of physical model based subband synthesis method for simulating ground clutter of wideband radars is studied in this paper. This method uses a general facet model to obtain subband echo contributions of a highly correla...
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A strategy of physical model based subband synthesis method for simulating ground clutter of wideband radars is studied in this paper. This method uses a general facet model to obtain subband echo contributions of a highly correlated segment of ground surface based on the observation that less randomness remains in a high-resolution cell. Such a segment consists of only a predominant reflector plus a complex random scatter from other weak factors. Then the subband contributions are synthesized to form the simulated clutter data of all resolution cells within the facet. Overlap scheme is used to smooth sudden change across adjacent facets. Because the subband scattering of different facet shapes have different types of frequency dependence, the proposed method is able to keep more detailed information of ground surface structure, resulting in a potential to give a high-fidelity clutter simulation.
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摘要 :
A strategy of physical model based subband synthesis method for simulating ground clutter of wideband radars is studied in this paper. This method uses a general facet model to obtain subband echo contributions of a highly correla...
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A strategy of physical model based subband synthesis method for simulating ground clutter of wideband radars is studied in this paper. This method uses a general facet model to obtain subband echo contributions of a highly correlated segment of ground surface based on the observation that less randomness remains in a high-resolution cell. Such a segment consists of only a predominant reflector plus a complex random scatter from other weak factors. Then the subband contributions are synthesized to form the simulated clutter data of all resolution cells within the facet. Overlap scheme is used to smooth sudden change across adjacent facets. Because the subband scattering of different facet shapes have different types of frequency dependence, the proposed method is able to keep more detailed information of ground surface structure, resulting in a potential to give a high-fidelity clutter simulation.
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摘要 :
A strategy of physical model based subband synthesis method for simulating ground clutter of wideband radars is studied in this paper. This method uses a general facet model to obtain subband echo contributions of a highly correla...
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A strategy of physical model based subband synthesis method for simulating ground clutter of wideband radars is studied in this paper. This method uses a general facet model to obtain subband echo contributions of a highly correlated segment of ground surface based on the observation that less randomness remains in a high-resolution cell. Such a segment consists of only a predominant reflector plus a complex random scatter from other weak factors. Then the subband contributions are synthesized to form the simulated clutter data of all resolution cells within the facet. Overlap scheme is used to smooth sudden change across adjacent facets. Because the subband scattering of different facet shapes have different types of frequency dependence, the proposed method is able to keep more detailed information of ground surface structure, resulting in a potential to give a high-fidelity clutter simulation.
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摘要 :
A strategy of physical model based subband synthesis method for simulating ground clutter of wideband radars is studied in this paper. This method uses a general facet model to obtain subband echo contributions of a highly correla...
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A strategy of physical model based subband synthesis method for simulating ground clutter of wideband radars is studied in this paper. This method uses a general facet model to obtain subband echo contributions of a highly correlated segment of ground surface based on the observation that less randomness remains in a high-resolution cell. Such a segment consists of only a predominant reflector plus a complex random scatter from other weak factors. Then the subband contributions are synthesized to form the simulated clutter data of all resolution cells within the facet. Overlap scheme is used to smooth sudden change across adjacent facets. Because the subband scattering of different facet shapes have different types of frequency dependence, the proposed method is able to keep more detailed information of ground surface structure, resulting in a potential to give a high-fidelity clutter simulation.
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摘要 :
The disadvantage of traditional processing in wideband passive radar is pointed out. At the basis of wavelet transform, a new method of wideband passive radar target detection is proposed, the detail of this method is explained, a...
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The disadvantage of traditional processing in wideband passive radar is pointed out. At the basis of wavelet transform, a new method of wideband passive radar target detection is proposed, the detail of this method is explained, and its application in white noise environment is simulated. Because the difference in scale between the signal and noise, the signal is restored, then with the usage of cross wavelet transform the parameters of target are estimated.
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This paper presents a new compact printed L-shaped monopole antenna for applications in ultra-wideband (UWB) systems such as home networks and various wireless systems. A miniaturization of the proposed antenna has been accomplish...
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This paper presents a new compact printed L-shaped monopole antenna for applications in ultra-wideband (UWB) systems such as home networks and various wireless systems. A miniaturization of the proposed antenna has been accomplished by using a parasatic element, resulting in a design with dimensions 25 mm × 25 mm × 1.6 mm. The antenna is printed on FR4 epoxy and is fed by SMA female connector. The return loss (Su) and voltage standing wave ratio (VSWR) are obtained using both HFSS and CST for different ground plane lengths. The new L-shaped design illustrates good UWB characteristics since it is capable of operating in the range 2-12.31 GHz. Simulation results for Su and VSWR show strong consistency in terms of the bandwidth for UWB operation, under the general criteria of S11 less than -10 dB and VSWR less than 2:1.
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摘要 :
This paper presents a new compact printed L-shaped monopole antenna for applications in ultra-wideband (UWB) systems such as home networks and various wireless systems. A miniaturization of the proposed antenna has been accomplish...
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This paper presents a new compact printed L-shaped monopole antenna for applications in ultra-wideband (UWB) systems such as home networks and various wireless systems. A miniaturization of the proposed antenna has been accomplished by using a parasatic element, resulting in a design with dimensions 25 mm × 25 mm × 1.6 mm. The antenna is printed on FR4 epoxy and is fed by SMA female connector. The return loss (Su) and voltage standing wave ratio (VSWR) are obtained using both HFSS and CST for different ground plane lengths. The new L-shaped design illustrates good UWB characteristics since it is capable of operating in the range 2-12.31 GHz. Simulation results for Su and VSWR show strong consistency in terms of the bandwidth for UWB operation, under the general criteria of S11 less than -10 dB and VSWR less than 2:1.
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