Research on the influence of the hottest phased ar

Research on the influence of phased array technology on electronic intelligence reconnaissance

Abstract: in view of the complexity and variability of RF signals caused by phased array radar technology, a radar reconnaissance data analysis method based on dynamic signal level simulation of radar RF signals is proposed. The phased array radar technology applied in typical phased array radar system is analyzed, and the real-time signal level simulation of phased array radar RF signal is carried out by using MATLAB 7.0 simulation tool software, the RF signal model is obtained, and the influence of phased array technology on electronic intelligence reconnaissance is analyzed

key words: phased array; Electronic intelligence; Reconnaissance; Radar RF signal

0 introduction

the wide application of modern electronic technology in military struggle and weapons and equipment makes it the most obvious feature of modern information war to compete for the initiative of electromagnetic spectrum, that is, to control electromagnetic power. The basis of controlling electromagnetic power is the reconnaissance and analysis of electronic intelligence. The traditional electronic information processing method is a semi-automatic processing method combining computer and expert system, and the false alarm rate of fully automatic processing is high. For the high variation and pseudo-random variation RF signals of phased array radar, this method has low speed and poor accuracy, and can not meet the needs of electronic intelligence in modern information war. The actual received signal model of the electronic intelligence reconnaissance receiver can be obtained by using the simulation tool to simulate the phased array radar at the signal level; It can effectively improve the analysis speed and accuracy of electronic intelligence (the software manual has an operation instruction diagram on how to create a new record), especially the variable transmission mode of phased array radar and the influence of pseudorandom RF signal transmission parameters on electronic intelligence reconnaissance. This method has a good effect

1 analysis of factors affecting electronic intelligence

1.1 Table 1 significance and content of dimensional deviation and appearance electronic intelligence

generalized electronic intelligence refers to the information intercepted from the signal of interest, and its signal is any non communication radiation signal. In a narrow sense, electronic intelligence refers to the observation results of the signals transmitted by the radar system in order to obtain all kinds of information about the radar. The electronic intelligence in the text refers to the latter. The value of electronic intelligence lies in the timely provision of information about threat systems (such as radars that guide aircraft or missiles to the target), as well as information about defense systems and important intelligence for electronic attacks. Electronic intelligence can be divided into two categories according to its purpose: radar electronic reconnaissance intelligence and electronic support intelligence. Radar electronic reconnaissance intelligence refers to the radar equipment information obtained through signal processing and data processing according to the RF signal of radar equipment received by reconnaissance. Electronic support intelligence usually refers to the intelligence of the battle situation and electronic attack style of local radars

the generation process of electronic intelligence is shown in Figure 1

through the design, synthesis, modification and processing of materials, the degradation performance of materials can be regulated according to different utilization needs. The generation of alarm can be divided into five steps:

(1) the electronic intelligence receiver measures the detected radar RF signal and obtains the full pulse data of the radar system

(2) sort and process the radar system full pulse data to obtain the radar system emitter data

(3) analyze and identify the radar system emitter data in pulse to obtain radar electronic reconnaissance intelligence based on radar working style

(4) based on the existing radar principle information, the simulation model is used as a tool to study the internal working mechanism of radar system for radar electronic reconnaissance intelligence, so as to achieve the purpose of individual identification of radiation sources

(5) use the radar tactical information obtained from the research on the internal working mechanism of the radar system to obtain electronic support information; Finally, the obtained radar support intelligence is directly applied to anti radiation strike, electronic suppression and other electronic offensive operations. This part is an important part of the application of electronic support intelligence

1.2 electronic intelligence reconnaissance equation

the literature points out that in free space, the radar transmission signal level received by the electronic intelligence receiver can be described by the following formula:

the purpose of phased array radar simulation is to obtain the adaptive RF signal of phased array radar. According to this purpose, the phased array radar system can be equivalent. The transmitting link of phased array radar simulation system is composed of radar anti countermeasure control system, transmitting system and transmitting antenna system. The receiving link of phased array radar simulation model is composed of receiving antenna system, receiving system, signal processing system and data processing system. The admission control system is used as the control system to connect the receiving and transmitting system. Because the purpose of simulation is to obtain the RF signal of phased array radar, the receiving link can be equivalent to the influence on the change of radar working parameter table in the acquisition and control system. When the simulation starts, the received signal of the radar is zero, and the ideal signal is transmitted according to the preset parameters. When the receiving system receives the target echo, it selects the optimal transmission parameters for transmission according to the echo signal. According to this method, it can be concluded that the simulation technology of phased array radar simulation system focuses on the phased array antenna line array and array synthesis technology and the transmission digital beam forming technology

2.2 simulation of linear array and array synthesis technology

Taylor line source synthesis method is a very effective method to describe the antenna linear array and array pattern in the ideal state. More importantly, the improved N-Parameter correction method can effectively suppress the sidelobe and constrain the zero position. Therefore, N-Parameter Taylor line source synthesis is widely used in the transmitting beam of phased array radar antenna

taylor n parameter distribution line source synthesis method can effectively constrain the position of the zero point of the lobe map, and can effectively suppress the sidelobe. Taylor uses sinc () as the basic function to form the pattern by adjusting the zero point position in the near region:

where: n is the zero point position of the pattern; When it is the beam spread factor, the function of this parameter is to make the first n side lobes smoothly transition to the 1/u envelope, and the side lobes are controlled

2.3 simulation of transmitting digital beam forming technology

multi beam antenna has many advantages, such as large detection range, high data acquisition rate, large coverage space, etc., so it has been widely used in radar transmitting beam. Transmit digital beam forming is to realize the amplitude weighting and phase shifting required by the traditional phased array transmit beam forming from the RF part to the digital part, so as to form the transmit beam

the RF energy at a point in the airspace is:

, where: D is the complex amplitude of the required signal,

the weighted output is:

the signal power output of the array is:

2.4 simulation of energy management technology of phased array radar system

phased array radar because its whole system can achieve agility, it is necessary to use feedback and optimization technology to manage the working state of the radar and select the most effective working mode. Managing the transmitted energy of phased array radar can maximize the utilization of the transmitted energy

the scanning mode of traditional radar is uniform scanning within a certain angle and continuous tracking of a group of targets, which can not solve the contradiction between instantaneous detection range and tracking accuracy, and phased array technology can effectively solve this contradiction. Phased array technology uses digital multi beam forming method to maximize energy utilization. Suppose that when the radar antenna is scanning, n pulses should reside at each beam position, then the radiation energy density in the unit elevation beam is:

, where: V is the elevation beam width

the total energy in the three-dimensional airspace is:

the principles of energy management are as follows:

taking the designated airspace as the constraint to maximize the energy saving factor. After analysis, it can be concluded that the parameters restricting the energy saving factor include: antenna gain, elevation power, beam dwell time

3 analysis of the influence of phased array technology on radar intercepted signal

3.1 RF model of radar intercepted signal at a certain point in space

because linear frequency modulation signal can effectively solve the problem of giving consideration to both range resolution and Doppler resolution, linear frequency modulation signal is mostly used as the transmitted signal of phased array radar, and linear frequency modulation signal is also used as the simulation model signal in this paper. The LFM signal can be represented by the following formula:

simulate the RF signal of phased array radar, and the simulation results are shown in figures 3 to 11

the abscissa in figures 3 to 9 is time (s); The ordinate is the signal amplitude (V) after normalization. The abscissa in figures 10 to 11 is the sine of the angle between the antenna direction and the true north direction; The ordinate is the normalized antenna power spectrum

(2) the wide application of phased array technology in antenna electronic scanning makes the transmitted beam change rapidly and the beam width is extremely narrow. Therefore, the operating range of the method relying on the reconnaissance of the main lobe of the radar transmitting antenna is greatly reduced statistically

(3) phased array technology and adaptive linear array synthesis technology make the antenna obtain much lower antenna sidelobe than the traditional antenna, which greatly reduces the reconnaissance effect of reconnaissance equipment relying on the reconnaissance sidelobe method