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Based on in depth study of internal structure and external interface of AD9854, applying singlechip to control its interior programmable register and related accumulator through parallel interface of AD9854, to explore feasible control method, after reiterative experiment, achieved programmable control on initial phase of oscillation of output pulse of AD9854. This method had applied on some radar echo signal simulator, fulfilled fixed objective echo signal synthesizing.

Aiming at the problem of common-frequency interference among gun-pointing radars, frequency agility technique was introduced. The reason why existing technique of frequency agility can’t investigate and identify common-frequency interference effectively was analyzed. A new frequency agility technique based on auxiliary channel and full-time reconnaissance and receiving is presented. Auxiliary channel investigates and identifies environmental signals full-time not intermittent, then uses microwave cancellation technique to eliminate local radar’s emission pulses. As a result, when auxiliary channel amplitude is greater than the main channel, it must be common-frequency interference. The above measures guarantee the accurate identification of common-frequency interference.

The phase noise performance of frequency source has a direct impact on the target measurement such as the adjacent channel interference of the electronic system, the transmission quality of information, the resolution of radar. In this paper, we achieved an X-band high stability, low phase noise frequency source which based on the DDS combination with frequency doubling technology. The test result shows that when the output of the frequency source is at 8.544GHz, the phase nosie is-103.58dBc/Hz at 1kHz and-101.94dBc/Hz at 10kHz.

In this paper, the basis function of TDCS system (Transform Domain Communication System) is used to design cognitive radar transmitter waveform. Based on the noise environment, the waveform can be adjusted adaptively. Then after clipping to reduce the PAPR (Peak to Average Power Ratio) of radar echo signal, the obtained signal is used as the next launch of the radar signal. The cognitive radar transmitter requires a nonlinear waveform to improve the efficiency of radar transmitter power amplifier, so reducing the PAPR of signal is essential. This paper presents the gray complementary sequence is applied to TDCS communication systems, and then it needs to reduce PAPR of signals by clipping. Proven, PAPR of the transmitted signal is maintained at about 3.25dB, and the signal has a low probability of intercept, high anti-interference ability and distant target detection range.

Based on the chirp signal radar using DDS technology, the waveform of the wideband chirp signal source is analyzed. By analyzing the system error model, the method that selecting the chirp steps in accordance with the digits of DDS phase truncation is proposed. It reduces the system errors caused by the phase truncation.

This paper proposed a target detection method in the presence of multiple jamming, which may come from mainlobe or sidelobe of the array antenna. The jamming direction-of-arrival (DOA) is estimated using MUSIC algorithm, and a multiple jamming cancellation beamformer is suggested, which is based on a FIR filer in space domain, the beamformer is followed by a pulse compression filter in frequency domain which can improve the resolution in time domain. We take a simulation experiment for our method, considering a digital array radar with pulse compression technique, the experiment indicate that the target detection method have a good performance and can be used in digital array radar system.

This paper introduces the basic principle of phase code pulse compression technology, the characteristics of phase coded pulse compression system, and the technical approach of radar to implement phase code pulse compression.

This paper has introduced a kind of method which can simulate the echo signal of radar receiver by the use of the Digital Radio Frequency Memory (DRFM) and Programable Logic Device (PLD).With the realization of actual circuit,the echo simulator can produce intermediate frequency and video signals.Therefore,with the help of the echo simulator, we can raise the detection ability of radar receiver system considerably. The structure of the simulator is simple but its function is great.The echo simulator can simulate intermediate frequency signals of radar receiver system for the first time.So the simulator can locate where isn’t work well of the radar receive system.

With the development of science and technology ,microwave measuring instrument become more important in the radar equipment maintenance support task.This paper expounds the principles of microwave measuring instrument work and test, describes the application of microwave measuring instrument in the maintenance detection of radar antenna feed system、radar antenna pattern test、power amplifier parameters measurement、the local oscillator test and receiving systems component test. Scientific applications of microwave measuring instrument is the important guarantee to ensure the radar equipment operate effectively.

Pulse compression technology is one of the key technologies in the field of modern radar signal processing, can effectively solve the contradiction between action distance and resolution. In this paper, a radar digital pulse compression system is designed and implemented based on FPGA with linear frequency modulated signal. The digital pulse compression module is designed using FFT IP core which can be reused in different periods of DPC, respectively performing FFT and IFFT calculation, so that the hardware consumption is saved significantly. Therefore, compared with other systems, the system designed in this paper has the characters of fast processing speed, high degree of modularity, real-time processing and short development cycle.

The main principle of radar non - contact life detection technology is the use of electromagnetic wave by the human body, the echo signal is modulated by the surface movement caused the life activities of the human body, so that some parameters of the return signal change. The research on the non contact detection technology, completed the construction of life monitoring system module of hardware, design of software algorithm, real-time data acquisition, and the use of special software algorithms, to detect these changes, and then extracting parameters of human life.

This paper study continuous wave radar data processing algorithm for low altitude detection, it is applied to continuous wave low altitude search radar data terminal, it can realize real-time correlation and track processing for the data of target echo and false alarm false alarm filtering, to get the real targets of track parameters. Finally, through the realization of FPGA, the experimental results achieve the precision of the system.

The dynamic target echo intermediate-frequency signal source can be used to detecting and repairing receiving system, signal processing system, display system of conventional radar. The output frequency which conducted by the signal source can be adjusted. The range of output signal frequency basically covers different types of radar, which has important practical application value on the maintenance of radar. The dynamic target echo intermediate-frequency signal source is make up of source processing unit, intermediate-frequency unit, monitoring unit, the time reference source, input and output driver board and power supply pulse generation. Pulse processing unit in the signal source is in the core status.

The matched filter of chaotic radar system proposed by Ned J. Corron can be implemented through low-cost analog devices. But the spectrum of transmitted signal of this system is dispersion, causing signal in the process of propagation prone to spectrum leaked. To solve the problem, this paper proposes a low-cost signal design method. In transmitter, making chaotic signal become a band-limited signal by filtering to shape the spectrum; in receiver, using synchronization and filtering to recover the chaotic signal. The proposed method is implemented with low-cost analog devices; in addition, the method is still valid when the SNR is as low as-20dB.

In order to improve the diagnosis rate of wavelet neural network algorithm for the radar circuit, for the network during operation there is poor convergence, the training error and shortcomings easy to fall into local minimum, the network is unable to continue training and testing, proposing a new algorithm of increasing the momentum of the wavelet adaptive neural network, can make the network run more stable, faster learning rate; By the Matlab simulation experiments show that the diagnosis rate of the improved algorithm is much higher than the ordinary one.

Recently, the concept of software radar has been proposed. The wide application of the digital technology has become a trend. With the development of modern radar system, the system requires higher and higher performance to the radar receiver. The technology of digital receiver has become an effective implementation method for high-accuracy and wide-band radar receiving systems. However, most of the digital receiver can only receive one wide-band signal with one center frequency. A multi-frequency digital receiver which can receive several center frequencies of signal simultaneously [1] is discussed in this paper. We also describe the theory and the design about digital receiver, introduce digital downconversion (DDC), FIR and decimation, digital beam forming and channel calibration. Based on the research, a realization of multi-frequency digital receiver based on FPGA is put forward. The analysis and simulation is made and the result shows the design of great performance.

Analysis on the operation principle of digital radio frequency memory range (DRFM) with range gate pull off/in (RGPO/RGPI), a model of jamming signal is found in this paper. The use of stretch in the process of radar seeker receive signal is considered, so that the actual target echoes and jamming echoes will be moved into different frequencies. Then a low pass filter can be utilized to cancel the jamming signal and the actual target echo can be rebuilt through inverse stretch dealing. The simulation results show that this method can effectively suppress jamming signal.

Radar obtains motion information of target from received modulated electromagnetic waves, which is usually periodical pulses or continuous waves. In this process, noise will affect the detection performance. However, as a modulated transmitting signal, noise has incomparable advantages over traditional radar. In this article, the mechanism of noise as modulation signal is introduced, and subsequently focused on the principles of distance ranging the corresponding estimation methods are proposed. Besides, the interference resistance characters of noise radar is verified by simulation.

A new type of tachometer carbon brush wear detection technology is proposed based on data acquisition and signal processing technology, the key of which is that the tachometer carbon brush output information is acquired and processed, moreover, the real time conditions of the carbon brush wear are detected and analyzed based on the time domain Eigen value analysis method. During the data processing process, the results of the dimensional parameter processing method are compared with the results of the dimensionless parameter processing method at the same time. Then, we find that the detecting precision is greatly promoted and measurement probability is guaranteed by reasonable threshold selection. Experimental results indicate that the technology proposed here has high stability, high reliability, and high detecting probability, which has great practical value and deserves being extended widely.

Pulse chasing is an important means to achieve foundation-bistatic radar space synchronization. The principle and working process of achieving space synchronization by using pulse chasing is described which is based on a motion platform in bistatic radar; and the requirements on the receiving beam width is derived. How to cause the error of space synchronization with pulse chasing and its factors are analysed in detail, then the simulation on error of receiving beam width and beam pointing has been realized.

The Chirp signal has been used widely in radar signal, radar echo wave can established to be Chirp model. The estimation of radar echo wave parameter is a important task in radar signal processing. In this paper, we introduced three theories and algorithms of detection and estimation of Chirp signal: 2D peak searching algorithm, two steps searching of maximum value algorithm and pre-estimation algorithm firstly. The parameter estimation precision and computation complexity in low SNR was simulated for these three algorithms. The final simulation indicate that the two steps searching algorithm of maximum value take on nice estimation accuracy and low computation complexity in contrast.

The step frequency radar is a wideband and high resolution system, which is widely used in target positioning and tracking. The echo signal model of step frequency radar consists of complex sine functions with different frequencies. The maximum likelihood function of multiple frequency components is deduced based on the model. The frequencies are calculated by Genetic Algorithm and the one dimension scattering centers are extracted.

Faced with complex electromagnetic environment and varieties of adaptive radar waveforms, radar signal analysis and identification becomes more and more complex. Considering two important physical quantities - time and frequency in modern signal processing methods, this paper proposes that the joint time-frequency analysis (JTFA) method based on fractional Fourier transform (FrFT) and short-time Fourier transform (STFT) is applied to adaptive radar signal processing. The simulation results show that the joint time-frequency analysis method is superior to single short-time Fourier transform, getting a better analysis of results. The joint time-frequency analysis method provides the joint distribution of the time domain and frequency domain for adaptive radar signal analysis and describes the relationship between signal frequency and time.

Ultra-Wideband (UWB) wireless communication is a new potential communication technology currently in its field. It becomes very popular in the world since it’s high performance, low radicalization and low cost. Currently UWB wireless system, we can call it Impulse Radio technology too, be invented in 20 century 1960s. But it was only used in military affairs field, bailout searching, radar location and so on. After civil using, it usually is used in indoor wireless LAN .In this paper, the development and application of UWB are introduced, the characteristic and limitation of UWB are simply analyzed. According to the simulating depending on Multipath channel, it shows increasing SNR about 1.5dB to the base of primary power district or increasing SNR about 1dB to primary power district and minor power district, we can get whole performance of RAKE receiver in perfect channel.

£o Based on judging the change of pulse amplitude of phase detecting, a new method of time domain coherency for the radar emitter sorting is proposed in this paper. We analyzed the theory of the signal coherency recognition method. Then, the mathematic derivation process and specific recognition steps of the new method are detailedly given. But above all, the new method can be applied into the signal sorting of radar emitter. Simulation results also reveal that this new method can effectively sort the radar emitter signals under the low signal-to-noise ratio, and it is a huge help to solve the problem of " leakage-batch ". Results demonstrate that the new method has strong theoretical value.

Recently,the problem of lack of radar teaching equipment is more and more prominent because of the large number of student in teaching of the large electronic equipment.For the problem,this paper firstly elaborated the hardware structure,overall structure, software design idea of the detection and maintenance platform for radar operation unit based on PC104.Then the paper finished the function test of the power supply module and signal module.At last, the paper showed the application effect in teaching, proved that the platform can enhance the equipment efficiency greatly and laid a good foundation for the teaching reform.

After introducing the ambiguity function theory of radar analysis, wideband ambiguity function about Direct Spread/Frequency Hopping (DS/FH) signal is derived out in this paper. From the point of signal simulation ambiguity figure, the tracking performance is studied and analyzed, that includes ambiguity character and signal resolution under the influence of frequency switching time and phase discontinuous. Conclusion shows the following design difficulty based on feasibility in DS/FH TT&C.

Smart jamming based on convolution modulation brings a great threat to active radar seeker. In order to counter the jamming, a method of orthogonal projection is designed. Firstly, both the mathematic models of linear frequency modulation (LFM) signal and convolution modulation smart jamming are made. Secondly, the anti-interference principle of orthogonal projection is analyzed, on the basis of which a reasonable filter is designed. Thirdly, simulations of signals respectively convolved with noise, triangle pulse sequence and rectangular pulse sequence are made, which verifies its good interference effects. The conclusion is that the method can effectively suppress the convolution modulation smart jamming.

According to IEEE Std 802.11p, a fast DOA estimation algorithm of multiple targets based on beam-forming techniques in OFDM radar-communication system for vehicular applications is discussed in this paper. The proposed algorithm has reduced computational complexity utilizing high order power of the inverse spatial covariance matrix without eigen-decomposition. Simulation results demonstrate it is suitable for vehicular application.

The clutter distribution of airborne radar with non-sidelooking uniform linear array antennas varies with ranges and interference in different range gates are not independent identically distributed vectors, so the performance of statistical STAP methods degrade heavily. In this paper, the range dependency problem is studied and a clutter nonstationarity reducing method is proposed. This method involves in the pre-processing of elevation cosine based vector extending and subsequently statistical STAP technique. Simulation results show the proposed method can reduce the clutter dispersion significantly and outperform conventional compensation methods.

In view of the traditional zero-angle memory device with low precision and to reduce errors caused by manual readout, this paper using electro-magnetic technology, designed a new zero-angle memory device based on proximity switch. Experimental results show that the device not only improves the repeatability and reduces the error, but also realize automatic demarcation.

This paper discussed the problem of two dimensional (2D) direction of arrival (DOA) estimation for multi-input multi-output (MIMO) radar. The minimum-redundancy linear array (MLRA) is introduced into the transmitting array and receiving array, which enables the high efficiency of the radar system. By utilizing the algorithm of multiple signal classification (MUSIC), we illustrate that the proposed scheme performs better than the uniform linear arrays (ULA) configuration under the same conditions. Simulation results verify the effectiveness of our scheme.

High stability and constant-temperature crystal oscillator as time standard, microcontroller as control core, the countdown frequency measuring electric circuit, rapidly and timely surveying the transmitting frequency during the constant radar transmitted pulse, is a digital frequency measurement module. This module is an important constituent part in digital automatic radar frequency control system, having been successfully applied in a self-adaption frequency control system of meter wave warning radar.

Multiple-input multiple-output (MIMO) radar with frequency diversity (f-MIMO) is applied to HF radar. An array processing model of f-MIMO HF radar is developed. To eliminate the grating lobe of f-MIMO radar beamforming, two approaches are proposed. One is to apply particle swarm optimization (PSO) algorithm to select the optimal carrier frequency combination. Another is to extract array elements from the virtual receive array to get the optimal sparse array structure, and the simplified physical receive array structure is proposed. Simulation results demonstrate the effectiveness of the method proposed.

The clutter distribution of an airborne multiple input and multiple output (MIMO) radar in non-homogeneous environment varies with ranges and samples in different range gates are not independent identically distributed vectors, so that the statistical space time adaptive processing (STAP) methods degrade heavily. A clutter suppression method for airborne MIMO radar in non-homogeneous environments is studied in this paper. Firstly, Space time autoaggressive (STAR) method is introduced to airborne MIMO radar for clutter suppression and then an AR model parameters estimation method for STAR is proposed to decrease the complexity of traditional method. Simulation results show the proposed method can estimate parameters exactly and rapidly with only few training samples and be fit for clutter suppression in non-homogeneous environments.

Automatic Dependent Surveillance Broadcast (ADS-B) is a recommended advanced surveillance technology in Future Air Navigation Systems by ICAO. ADS-B is the technology that can provide the surveillance capabilities based on GNSS and ground-air data link. Because the frequency and the coding mechanism are in public, it is easy to be disturbed and deceived. The essay analyzed some traditional methods to check ADS-B information, and introduced a new checking method based on Direction-finder Antenna that fused radio character and Kalman Filter algorithm together . It can identify the false ADS-B message efficiently.

Multiple-input multiple output (MIMO) radar has been widespread concern in the domestic and foreign researchers. Bistatic radar draws on the great success of MIMO technology in the communications field, and it has many advantages over conventional radar. The direction angles estimations of bistatic MIMO radar are researched. To contrast traditional radar DOA estimates, the direction vector of the bistatic MIMO radar is the Knonecker plot of the emission vector and reception vector, that two-dimensional direction angles is estimated. To solve this problem, the principle of bistatic MIMO radar signal model is in-depthly researched.By proposing Capon dimensionality reduction method, the two-dimensional directions of the dual-based MIMO radar are estimated, and computer simulation is to verify the effectiveness of the method.

In order to realize the zero-range-target simulation, the echo delay simulation method for the fixed radar and simulator is given. By this method, zero-range target simulation can be realized. Finally, it is verified by a computation example.

This paper links the parameter estimation problem of polarization diversity bistatic multiple-input multiple-output (MIMO) radar to propagator method (PM), and proposes an algorithm for joint estimation of direction-of-departure (DOD), direction-of-arrival (DOA) and polarization information for bistatic MIMO radars. PM algorithm is a low complexity algorithm since it requires no eigen-value decomposition (EVD) of the covariance matrix of the received data. The proposed algorithm can estimate the multiple parameter accurately, while achieve paired parameters estimation automatically. Through obtaining polarization information, MIMO radars can further increase the target location and identification accuracy. Simulation results verify the feasibility and effectiveness of the proposed algorithm.

For intelligence transportation system,it is necessary to resolve the problems of multiple targets detection and vehicle longitudinal control with high level response capability. False targets can appearance because of mistaking the combination of these beat frequencies of Frequency Modulate continuous wave radar. A novel waveform named double-slope symmetrical saw-tooth wave is proposed and its corresponding algorithm is also introduced to resolve the problem of multiple targets detection for automotive anti-collision radar. About vehicle longitudinal control, the purpose of this paper is to propose new approach to estimating relative acceleration information for vehicle longitudinal control without inter-vehicle communication. Computer simulation results and theoretical analysis proved that the proposed methods are effective and practical for multiple targets detection and acceleration estimation in intelligence transportation system.

Based on fuzzy logic control adaptive bandwidth PLL design is presented for the problem of tracking poor stability and low accuracy when a certain type of radar tracking dynamic spacecraft. This method is mainly through fuzzy logic controller, adaptive level is determined by control rule of input respectively, and the outputs of rules are weighted combined to control the coefficient of loop filter, thus adjusting automatically the loop bandwidth, and enhancing the tracking stability of radar equipment and improving ranging accuracy. The simulation results show that the fuzzy logic control adaptive bandwidth PLL has higher tracking stability and accuracy.

The echoes of pulse radar from maneuvering targets are amplitude modulation and frequency modulation (AM-FM) signal. At present, the methods of estimating parameters of AM-FM signal are time-frequency analysis method, empirical mode decomposition and empirical wavelet transform based adaptive data analysis methods. This paper takes the idea of intrinsic mode function in guessing the initial phase, and applies the newly developed sparse time-frequency analysis method in AM-FM signal parameter estimation. Simulation results show that the estimating performance of this method in AM-FM signal is good under different SNR and it has low computational cost, and this method is applicable in target acceleration and velocity estimation.

In recent years radar life detector is the rapid development product of information technology and Biomedical Engineering, and its core is to not contact with the human body, but to realize the detection of the parameters of human life which has a breakthrough, and to explore with full range. This paper first analyzes the principle of radar life detection system and the implementation scheme of each module technology. Based on this, DSP digital signal processing method is used to design the structure system of radar life detector. Further based on the DSP signal processing principle, PD distance tracking is used to approximately simulate the time domain of human heartbeat signal. The results show that the tracking effect that is under this structure is remarkable, which has provided technical support for the practice of the area to a certain extent.

A new method based on fractional correlation theory for estimating the Doppler and multipath time delay of the wideband echoes for LFM pulse radar by only one pulse signal is presented. First, the Doppler is estimated by energy cumulation of multipath component based on fractional correlation transform. Then, an order-reduced signal is reconstructed combining the Doppler with the prior knowledge of the transmitted signal, and the echoes signal is converted to many single-frequency signals. Finally, the multipath time delay is obtained by the dechirping method. The method is adapted for low SNR noise, can restrain the affection of the cross-items, and has a high time-delay estimation resolution. Some computer simulations are given in this paper and the results show that the new method is valid.

This paper discusses photovoltaic radar target simulator using NN, which provides a virtual simulation test environment for photovoltaic radar. A description of the controller architecture and associated stability analysis is given, followed by a more in-depth look at its application to a tiltrotor aircraft. Finally, it is proved that the control process of the photovoltaic simulator has superior performance and expected effect.

A novel OFDM radar processing algorithm using pilot signal is proposed in this paper. Based on the prior knowledge of the pilot signal in OFDM symbol in communication system, the receiver can estimate the transmitter's range, velocity by the processing of the received modulation domain signal. In addition, we test the approach by the OFDM frame signal of the famous IEEE Std 802.11p, the results show it can work robustly and is very suitable for the vehicular application.

First analyzing electromagnetic compatibility system of the wired circuit, and then electromagnetic shielding, PCB board electromagnetic compatibility and filtering are used to develop an anti-broadband electromagnetic interference wired phone. It can resolve practical problems of SLT dialing error in strong electromagnetic interference, voice unclear and intermittent communication. After 30 days test, experiment shows that in 50m radiating field of high-power VHF radar or shortwave radio, speech intelligibility of phone designed was higher than that of general phone and had no whistling or ringing.

In order to develop an anti-broadband electromagnetic interference wired phone, speech enhancement, electromagnetic shielding, PCB board electromagnetic compatibility and filtering are the usual measures. Realization of speech enhancement can resolve practical problems of SLT dialing error in strong electromagnetic interference, voice unclear and intermittent communication. The experiment shows that in 50m radiating field of high-power VHF radar or shortwave radio, speech intelligibility of phone designed was higher than that of general phone and had no whistling or ringing.

To solve the problem of sliding-type scattering center and the problem of angle limitation of single radar, a kind of method for extracting three-dimensional micro-motion characteristics of ballistic target based on netted radars was proposed. Firstly, A new feature extraction method based on half period delay multiplication was introduced which establishes the relationship of sliding-type scattering center and ideal scattering center, then making use of the expand hough transformation, the parameters of echo signals were extracted. At last, the three-dimensional micro-motion features and the structure features were obtained by solving nonlinear multivariable equation systems which were established by the multi-view of netted radar. Simulation validated the method can get both the high estimating precision and the three-dimensional micro-motion parameters.

The wave measuring system can supply massive wave data information, but these data cannot be applied to navigation practice directly. This thesis set WaMoSII(The Wave and Surface Current Monitoring System) as an example , introduced the system and principle of WaMoSII, reprocessed the supplied wave measuring information, and established wave information database based on SQL Server. Through study on the MTF (modulation transfer function), it proved the distribution similarity between practical wave spectrum and the supplied frequency and spectral density information of WaMoSII, then we implemented the function that extracting relative spectrum information then transforming into absolute spectrum information automatically based on MATLAB program, it can provide convenience for wave measuring radar information for navigating application.