This paper analyzed some primary techniques of anti-jamming technology for radar. Simulation results show the merit of each method. And it proposed a new idea that combines some typical anti-jamming techniques together. It was a more effective way of the integrative anti-jamming technology. Keywords-Pulse repetition frequency; transmitting power; polarization filter; comprehensive using I. FOREWORD Responding to the development of the radar, many kinds of Anti-radar detection measures and jamming technology have been designed one after another which lead to the operating environment of the military radars becomes worse and has a worse impact on the survival and the performance of the radar. The current radar is facing serious issues like "Four threats". In order to develop and survive in the current environment, the radar must have some breakthrough in the theory and the system. So the first research problem of the ECCM is the radar application under the jamming[1][2].Radar anti-jamming technology has two parts -the anti-jamming techniques and the avoid-jamming techniques.In order to work more efficiently, the radar needs to give an overall consideration and application on these two parts.There are more than one hundred anti-jamming measures nowadays which are concentrate on waveform selection countermeasure, power countermeasure, frequency-domain countermeasure, polarization countermeasure and clutter suppression ect. [3][4]. These measures not only include the anti-jamming techniques improving but also the radar tactical's rational consideration and application. According to the characteristic of these techniques, this paper combined these typical techniques together, and this can exert radar's performance efficiently. II. RADAR ANTI-JAMMING TECHNOLOGY A. the choosing of the PRI The choosing of the PRI is crucial to radar's anti-jamming. Different PRIs have different anti-jamming performance. So choosing a better PRI is the first consideration for radar's anti-jamming performance. For the hostile party, the radar signal detection is the premise of jamming., We can implement the best efficiency jamming on condition that we detect the PRI exactly.Assumed the PRI of the pulse signal we launched is a constant and it is 300us. The hostile scout not only can intercept our emitter signal, but also intercept a pulse signal which PRI is 230us and it's span is 10%. In order to offer jamming reference, the scout need to sort and recognize them after received this signals. If the scout sort and recognize the signal based on the PRI, using PRI transformation arithmetic to process the pulse signal. At last we got fig 1. From the fig 1, we know that the PRI of the received signals are 230us and 300us respectively. This message offer a impactful help to implement the jamming and put our radar at a disadvantage place in anti-jamming.If our emitter signal is a pulse signal whose PRI is 300us and span is 20%, the scout used PRI transformation algorithm to process the pulse signal. Then we get fig 2. From the fig 2, 978-1-4244-5...

Direct current transformer (DCT) is a key piece of equipment in direct current (DC) microgrids, and the mainstream topologies mainly include LLC resonant converter (LLC) and dual active bridge (DAB). In this paper, a novel bi-directional buck/boost + CLLLC cascade topology is proposed for the input-series-output-parallel cascade converter system of a DC microgrid. To solve the problem that frequency variation causes the converter to deviate from the optimal operating point, resulting in low efficiency, and the inability to achieve a soft switching function. The CLLLC converter operates near the resonant frequency point as a DCT, only providing electrical isolation and voltage matching, while the buck/boost converter controls the output voltage and the voltage and current sharing of each module. Compared to other cascaded converter systems, the cascaded converter proposed in this paper has high efficiency, simplifies the parameter design, and is suitable for wide input and wide output operating conditions. The system adopts a three-loop control strategy, establishes the small-signal modeling of the system, and its stability is verified by theoretical analysis and simulation. The simulation and experimental results verify the correctness of the proposed cascaded converter based on buck/boost + CLLLC and the effectiveness of the control strategy.

Aiming at the dense false target jamming, the existing research does not consider the problems of true and false target identification and position estimation at the same time. A method of dense false target jamming suppression is proposed based on multiple-input multiple-output frequency diverse array (FDA-MIMO) radar network, which makes full use of the different characteristics of true and false targets in the space-time two-dimensional range distribution. It discriminates true and false targets and locates true targets and jamming sources in transmit-receive two-dimensional frequency domain. Then other radars in the information sharing network are instructed to silence sector at the location of the jamming source to reduce the jamming power into the radar. The netting radars capabilities of target detection and jamming suppression are improved by this method.

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