Now showing 1 - 5 of 16
- ItemResearch on Test Method of Ignition Temperature of Electric Explosive Device under Electromagnetic Pulse(Společnost pro radioelektronické inženýrství, 2021-09) Wang, Biao; Sun, Yongwei; Wei, Guanghui; Wang, Xuetian; Gao, HongminThe safety and reliability of electric explosive device, as the most sensitive initiating energy for igniting powder and explosive, directly impact those of weapon system. The safety and reliability of the electric explosion device were determined by the ignition temperature of the electric explosion device. Based on the conservation of energy and Fourier's law, a mathematical model was built for the relationship between the temperature rise of the bridge line and the amplitude of the electromagnetic pulse. In the experiment, the semiconductor band gap temperature measurement technology was used, and the correctness of the mathematical model was verified by altering the amplitude of the pulse signal. Then, the 50% ignition excitation of the device was determined with the Bruceton method and the statistical theory. According to the built mathematical model, the ignition temperature of the electric explosion device was determined as 412 ℃. In this paper, the measurement method of the ignition temperature of the electric explosive device was developed, which could act as a technical means for the safety assessment of the electromagnetic environment of the weapon system. Moreover, this method is critical to improve the safety and survivability of the weapon system in the complex electromagnetic environment.
- ItemLinear and Non-Linear Synthesis of Unequally Spaced Time-Modulated Linear Arrays Using Evolutionary Algorithms(Společnost pro radioelektronické inženýrství, 2021-09) Patra, Somnath; Mandal, Sujit Kumar; Mahanti, Gautam Kumar; Pathak, Narendra NathA novel method of designing unequally spaced time-modulated arrays (UESTMAs) by handling fewer optimization parameters with reduced problem dimension is presented in this paper. For synthesizing UESTMA, two design parameters, specifically, the non-linear parameter - element position, and the linear parameter – on-time durations are optimized in two steps. Different possible cases of linear and non-linear synthesis methods such as, position-only (PO), on-time only (OTO), position then on-time (PTOT), on-time then position (OTTP), and simultaneous position on-time (SPOT) are considered. To examine the performance of the synthesis methods, three global search stochastic algorithms based on differential evolution (DE), teaching-learning-based optimization (TLBO) and quantum particle swarm optimization (QPSO) have been employed to achieve the array pattern with significantly suppressed side lobe levels and sideband levels. Through comparative study, it is observed that the two step non-liner to linear synthesis method by fewer optimization parameters is efficient to provide better pattern with less computation time.
- ItemHigh-Selectivity Bandpass Filter Based on Two Merged Ring Resonators(Společnost pro radioelektronické inženýrství, 2021-09) Weng, Xiao-yu; Xu, Kai-da; Guo, Ying-jiang; Zhang, An-xue; Chen, QiangA high-selectivity bandpass filter (BPF) based on two merged ring resonators is presented in this paper. The structure of this proposed BPF can be seen as the two one-wavelength ring resonators merged each other by sharing the common λg/2 microstrip line. Due to symmetric structure, it can be analyzed by even- and odd-mode method and the locations of six transmission zeros are calculated using input impedance deductions. For further demonstration, a BPF example centered at 2 GHz is fabricated with high frequency selectivity. The measured 3-dB fractional bandwidth is 11% (1.89-2.11 GHz) and insertion loss is less than 2 dB in the passband. Good agreement between simulation and measurement verifies the feasibility of the design method.
- ItemRadio Frequency Identification Sensing Chipless Tag for Permittivity Monitoring of Specific Sizes Materials(Společnost pro radioelektronické inženýrství, 2021-09) Sakouhi, Soumaya; Raggad, Hedi; Gharsallah, Ali; Latrach, MohamedIn this paper, a novel Radio Frequency Identification chipless tag for permittivity sensing characterized by a reduced size, an original shape and a low manufacturing cost is presented. The tag consists of a linear shape taken with multiple linear slots etched on the metal patch, ensuring a multi-frequency response. It enables the development of a robust tag with 8 bits as data capacity within a reduced surface is of 17.5×23 mm². Hence, using the frequency Domain Approach, the chipless tag is able to obtain more than 64 different binary states, by the utilization of the frequency shifting technique and the bandwidth distribution. Also, the operating frequency band ranges from 3.5 to 6.5 GHz. The new design is simulated, realized and experimentally validated by a bi-static measurement in the anechoic chamber. Then, preliminary tests are used for defining the Radio Frequency sensing chipless tag for permittivity monitoring, and proving its feasibility to control the evolution of a material over time or after use.
- ItemHigh-Selectivity Reflectionless Unbalanced-to-Balanced Filtering Power Combiner(Společnost pro radioelektronické inženýrství, 2021-09) Zhu, Zihui; Wang, Zhongbao; Bai, Yu; Liu, Hongmei; Fang, ShaojunA high-selectivity reflectionless unbalanced-to-balanced (UTB) filtering power combiner is proposed. The proposed power combiner composes of two absorbing branches, two filtering sections, two transmission lines, a grounded resistor, and a phase inverter. Two transmission zeros respectively located at the lower and upper sides of the passband are achieved by the filtering sections, resulting in high selectivity. The input-port reflectionless response in the bandstop region is obtained by the absorbing branch. A 1.0-GHz UTB filtering power combiner is designed and fabricated. Finally, the measurement performances are given in this paper. The input-reflection absorptive bandwidth and transmission bandwidth are measured as 545 MHz and 132 MHz, respectively. The absorptive bandwidth is 4.12 times the transmission bandwidth.