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1994 Vol. 16, No. 3
Display Method:
1994, 16(3): 225-231.
Abstract:
A new partial joint-domain spatial-temproal adaptive processing with time-space configuration is proposed, based on the properties of clutter returns received by an airbore phased array radar on which a side phased array antenna is placed. The principle and performance of the propsoed processor are analyzed in detail, and compared with those of two other processors. Theoretical analysis and computer simulation results show the excellent performance of the processor, particularly when targets are close to mainlobe clutter.
A new partial joint-domain spatial-temproal adaptive processing with time-space configuration is proposed, based on the properties of clutter returns received by an airbore phased array radar on which a side phased array antenna is placed. The principle and performance of the propsoed processor are analyzed in detail, and compared with those of two other processors. Theoretical analysis and computer simulation results show the excellent performance of the processor, particularly when targets are close to mainlobe clutter.
1994, 16(3): 232-237.
Abstract:
An effective broadband modified B sandwich as radome s layer structure is adopted. The power transmission coefficient of this sandwich is over 80% under large incident angle (0-70) and broadband (0-40GHz). The difference of insertion phase delay (IPD) between perpendicular polarization and parallel one is very small.
An effective broadband modified B sandwich as radome s layer structure is adopted. The power transmission coefficient of this sandwich is over 80% under large incident angle (0-70) and broadband (0-40GHz). The difference of insertion phase delay (IPD) between perpendicular polarization and parallel one is very small.
1994, 16(3): 238-243.
Abstract:
A theory of EM wave propagation through magnetic multilayers and superlattices is presented based on the propagation matrix of a magnetic film. By using the P matrix, the transmission and reflection coeffcients of layered magnetic media, including: (1) semi-infinite magnetic surfaces, (2) magnetic multilayers, (3) semi-infinite magnetic superlattices, are obtained. The numerical results show that the EM modes of a magnetic layer system are excited and manifested as the sharp dips in the S-polarized reflection, and the dispersion curves of magnetic polaritons can be measured by a method similar to attenuated total reflection (ATR) technique.
A theory of EM wave propagation through magnetic multilayers and superlattices is presented based on the propagation matrix of a magnetic film. By using the P matrix, the transmission and reflection coeffcients of layered magnetic media, including: (1) semi-infinite magnetic surfaces, (2) magnetic multilayers, (3) semi-infinite magnetic superlattices, are obtained. The numerical results show that the EM modes of a magnetic layer system are excited and manifested as the sharp dips in the S-polarized reflection, and the dispersion curves of magnetic polaritons can be measured by a method similar to attenuated total reflection (ATR) technique.
1994, 16(3): 244-251.
Abstract:
The exact energy flow pattern on the axis of a circular disk by transient excitation is presented. It is shown that non-decaying region does not appear when the source is chosen to be a rectangular pulse, on the contrary, there exists a uprising region on the axis when the width of the pulse is less than a/c. After reaching its maximum value, the energy decays slowly until the law of r-2 is met. The scale of the uprising region is dependent upon the size of the antenna and the width of the pulse. The energy flow line tube excited by a harmonic wave is also given. It is also shown that there is a oscillatory region near the source, the amplitude is also uprising, which is quite different compared with the conclusion drawn by S. Silver (1949). Finally, the phenomenon of energy uprising in time domain is explained and some problems about the electromagnetic missiles are also expounded.
The exact energy flow pattern on the axis of a circular disk by transient excitation is presented. It is shown that non-decaying region does not appear when the source is chosen to be a rectangular pulse, on the contrary, there exists a uprising region on the axis when the width of the pulse is less than a/c. After reaching its maximum value, the energy decays slowly until the law of r-2 is met. The scale of the uprising region is dependent upon the size of the antenna and the width of the pulse. The energy flow line tube excited by a harmonic wave is also given. It is also shown that there is a oscillatory region near the source, the amplitude is also uprising, which is quite different compared with the conclusion drawn by S. Silver (1949). Finally, the phenomenon of energy uprising in time domain is explained and some problems about the electromagnetic missiles are also expounded.
COMPUTER AIDED MEASUREMENT OF THE ELECTRO- MAGNETIC PARAMETERS FOR THE MICROWACE ABSORBING MATERIALS
1994, 16(3): 252-257.
Abstract:
A novel method involving multiple impedance measurements and optimization algorithm for the reconstruction of electromagnetic parameters is presented. Computer-aided analysis is used in all processes. Experimental results including teflon and some kinds of microwave absorbing materials are given.
A novel method involving multiple impedance measurements and optimization algorithm for the reconstruction of electromagnetic parameters is presented. Computer-aided analysis is used in all processes. Experimental results including teflon and some kinds of microwave absorbing materials are given.
1994, 16(3): 258-266.
Abstract:
Based on the work of Zhao Yang et al. (1989), the producing conditions and frequency domains of the modulation instability in monomode optical fibers with high-order nonlinearity are given in normalized form. The requirements of group velocity dispersion for the existence of maximal modulation growth are obtained. Some new results which are very useful in practical applications of the modulation instability are demonstrated by the numerical examples.
Based on the work of Zhao Yang et al. (1989), the producing conditions and frequency domains of the modulation instability in monomode optical fibers with high-order nonlinearity are given in normalized form. The requirements of group velocity dispersion for the existence of maximal modulation growth are obtained. Some new results which are very useful in practical applications of the modulation instability are demonstrated by the numerical examples.
1994, 16(3): 267-274.
Abstract:
Two approaches to the design of the time-varying cascaded filters used in radar clutter rejection are presented. In the first approach, by fitting the cascaded filter to the noncascaded filter, the time-varying cascaded filter can be designed, which makes it possible that the time-varying cascaded filter behaves just like an optimum clutter filter. The second approach can be used to design the second-stage filter in a time-varying cascaded one by setting zeros in its equivalent overall frequency response. It has been shown that the frequency response of the second-stage filter in the time-varying cascaded filter is difficult to express, however, is convenient to be involved in the overall response.
Two approaches to the design of the time-varying cascaded filters used in radar clutter rejection are presented. In the first approach, by fitting the cascaded filter to the noncascaded filter, the time-varying cascaded filter can be designed, which makes it possible that the time-varying cascaded filter behaves just like an optimum clutter filter. The second approach can be used to design the second-stage filter in a time-varying cascaded one by setting zeros in its equivalent overall frequency response. It has been shown that the frequency response of the second-stage filter in the time-varying cascaded filter is difficult to express, however, is convenient to be involved in the overall response.
1994, 16(3): 275-283.
Abstract:
The modeling method for the elements with characteristic family, which is presented by L. O. Chua (1977), is modified, then the one dimensional fluctuating canonical picecwise-linear model is obtained. It is an efficient model. The algorithm for canonical piecewise-linear dynamic networks with one dimensional fluctuating model is discussed in detail.
The modeling method for the elements with characteristic family, which is presented by L. O. Chua (1977), is modified, then the one dimensional fluctuating canonical picecwise-linear model is obtained. It is an efficient model. The algorithm for canonical piecewise-linear dynamic networks with one dimensional fluctuating model is discussed in detail.
1994, 16(3): 284-289.
Abstract:
This paper completely breaks up the real type polynomial public-key cryptosystems by computing the equivalent secure keys. And some computational problems related to securities of cryptosystems are discussed.
This paper completely breaks up the real type polynomial public-key cryptosystems by computing the equivalent secure keys. And some computational problems related to securities of cryptosystems are discussed.
1994, 16(3): 290-295.
Abstract:
The influence of silicon slice flatness on bonding technology and the relation between foreign particle and resulting bubble are quantitatively presented by the elastic theory. It is demonstrated experimentally by X ray double crystal dif-fractometry and infrared transmission imager.
The influence of silicon slice flatness on bonding technology and the relation between foreign particle and resulting bubble are quantitatively presented by the elastic theory. It is demonstrated experimentally by X ray double crystal dif-fractometry and infrared transmission imager.
1994, 16(3): 296-303.
Abstract:
From phase equation in an electron cyclotron autoresonance maser (CA-RM) amplifier the interaction between beam and electromagnetic waves is investigated with help of four-dimesional Maxwell equations, electromangetic-field tensor, energy-momentum tensor. The new phase equation is transformed by Lorentz transformation. Being non-longitudinal electro-field component, presence of longitudinal energy change between longitudinal moving beam and TE(Hmax) mode is jutified in theory.
From phase equation in an electron cyclotron autoresonance maser (CA-RM) amplifier the interaction between beam and electromagnetic waves is investigated with help of four-dimesional Maxwell equations, electromangetic-field tensor, energy-momentum tensor. The new phase equation is transformed by Lorentz transformation. Being non-longitudinal electro-field component, presence of longitudinal energy change between longitudinal moving beam and TE(Hmax) mode is jutified in theory.
1994, 16(3): 304-309.
Abstract:
The relations between the finite impulse response (FIR) digital filter and some microwave circuits are determined. In accordance with the relations, these microwave circuits can be designed in time domain, and the window function technique can be introduced into the method. Here the design examples are given to demonstrate that the design method is simple and effective.
The relations between the finite impulse response (FIR) digital filter and some microwave circuits are determined. In accordance with the relations, these microwave circuits can be designed in time domain, and the window function technique can be introduced into the method. Here the design examples are given to demonstrate that the design method is simple and effective.
1994, 16(3): 310-314.
Abstract:
The propagation behaviors of TM mode in nonlinear slab dielectric optical waveguide were studied. By using graphic method the dispersion equation was resolved. Finally the various physical mechanisms were explored.
The propagation behaviors of TM mode in nonlinear slab dielectric optical waveguide were studied. By using graphic method the dispersion equation was resolved. Finally the various physical mechanisms were explored.
1994, 16(3): 315-320.
Abstract:
The radiation fields of the Archimedean spiral antenna are derived by approximating the spiral with a series of semicircles. The formulas are developed to calculate radiation fields of the spiral antennas on an aircraft by applying the GTD. The calculated results agree well with the experimental ones.
The radiation fields of the Archimedean spiral antenna are derived by approximating the spiral with a series of semicircles. The formulas are developed to calculate radiation fields of the spiral antennas on an aircraft by applying the GTD. The calculated results agree well with the experimental ones.
1994, 16(3): 321-326.
Abstract:
A recognition and processing method of document form background information is presented. First, an original form, called Background Information Form Image (BIF1), is scanned. The same kind of forms, which is filled by various characters that one wants to recognize and process, called Useful Information Form Image (UIF1), is stored. Then, a geometric remedy of UIFI is used for the best matching with the BIFI. A digital logical operation is carried out in order to erase the most of background information and an intelligent correlation technique is available to completely delete the remained background information. This method is suitable for processing various forms, including background and useful information printed or filled with same colour. It can continuously process same kind of UIFIs with the input of BIFI only once. The document forms are shown and satisfactory results are obtained.
A recognition and processing method of document form background information is presented. First, an original form, called Background Information Form Image (BIF1), is scanned. The same kind of forms, which is filled by various characters that one wants to recognize and process, called Useful Information Form Image (UIF1), is stored. Then, a geometric remedy of UIFI is used for the best matching with the BIFI. A digital logical operation is carried out in order to erase the most of background information and an intelligent correlation technique is available to completely delete the remained background information. This method is suitable for processing various forms, including background and useful information printed or filled with same colour. It can continuously process same kind of UIFIs with the input of BIFI only once. The document forms are shown and satisfactory results are obtained.
1994, 16(3): 327-331.
Abstract:
A complete model of metal-semiconducter-metal-photodetector (MSM-PD) is presented. It can be implemented in any circuit simulator. Simulated DC chsracteristics for an MSM-PD are in good agreement with reported results.
A complete model of metal-semiconducter-metal-photodetector (MSM-PD) is presented. It can be implemented in any circuit simulator. Simulated DC chsracteristics for an MSM-PD are in good agreement with reported results.
1994, 16(3): 332-336.
Abstract:
By choosing the highest possible inductively coupled branchs and all current sources as links, the loop equations are directly formulated. The network may contain all-inductor cut-sets. The order of the presented loop equations is less than that of the modified modal approach equations. An example is given.
By choosing the highest possible inductively coupled branchs and all current sources as links, the loop equations are directly formulated. The network may contain all-inductor cut-sets. The order of the presented loop equations is less than that of the modified modal approach equations. An example is given.
