High power PULSEs with low widths have many applications in radiation generator devices as flash radiography and high power microwave generators. One of the COMPRESSION methods of high power PULSEs is MAGNETIC PULSE COMPRESSION. In this paper a Tesla generator with saturated core which produces a 200k V voltage PULSE has been designed and then the effect of saturation of the core in the COMPRESSION of the output PULSE using Proteus and CST EM Studio codes was studied. Our studies showed that with saturation of the transformer’s core, the MAGNETIC permeability and hence the inductance of the transformer’s coils will decrease and consequently the frequency of current oscillations in the transformer will momentarily increase where it will result in the decrease of the output PULSE width.

Background and Objectives: Dielectric Barrier discharge (DBD) is a suitable method to generating Non-thermal plasma at atmospheric pressure, which utilizes PULSEd power supplies as exciters. Increasing PULSE voltage range and frequency and compactness are important issues that should be taking into consideration. Methods: The high voltage PULSE generators which are introduced in the literature have some disadvantages and complexities such as need of additional winding to reset the transformer core and operating under hard switching which increases electroMAGNETIC noise and loss. The leakage inductance of the high voltage transformer increases the rise time of the PULSE which is undesirable for DBD applications. The energy stored in the leakage inductance causes the voltage spike across the switch, witch necessitates the use of snubber circuits. The main contribution of this paper is a new high voltage PULSE generator with the following characteristics, 1) a capacitor is paralleled with the main switch to reset the transformer core and to provide the soft switching condition for the switch. 2) The resonant charging technique is used which doubles the secondary winding voltage which reduces the turns ratio of high voltage transformer for a certain output PULSE peak. 3) The sharpening circuit using MAGNETIC switch produces a sharp high voltage PULSE. Results: The proposed high voltage PULSE generator is designed and simulated using Pspice software. To verify the theoretical results, a prototype with the input voltage 48 V, the output voltage PULSE 1. 5 kV, and the rise time of the output PULSE 50 ns is constructed and tested. Conclusion: This paper proposes a new PULSE generator (PG). The proposed PG uses three techniques named forward, resonant charging, and MAGNETIC switch to produce a high-voltage nanosecond PULSE. The resonant charging double the secondary voltage of the PULSE transformer, which causes reduction in turn ratio of the PULSE transformer and decreases the weigh, volume, and price of the PT. The MAGNETIC switch section finally produces a nanosecond high-voltage PULSE. The magnitude of the output PULSE can be varied using the input source voltage, the MS reset current and the duty cycle. The core of the PULSE transformer resets by using a capacitor paralleled with the switch and the PG does not need any additional reset winding like the conventional DC-DC forward converter.

The matched filter in the radar receiver is only adapted to the transmitted signal version and its output will be wasted due to non-matching with the received signal from the environment. The sidelobes amplitude of the matched filter output in PULSE COMPRESSION radars are depended on the transmitted coded waveforms that extended as much as the length of the code on both sides of the target location. In order to detect a weak target in vicinity of strong target, the sidelobes of the matched filter output resulting from the strong target masked the weak target and didn’ t detect its. Generally, the radar dynamic range is defined by the maximum power ratio to the minimum detectable power that is depended on the level of the threshold and the sidelobe levels. Adaptive algorithms suppress the sidelobe levels to noise level with condition of maintain the range resolution and therefore increase the dynamic range. In this paper, an improved algorithm (in terms of computational cost and Doppler robustness) is proposed based on the minimum mean square error (MMSE) estimator denoted as Flexible Filter Length-Adaptive PULSE COMPRESSION Repair (FFL-APCR), which filter length depends on the length of transmitted code. It is also shown that the length of the code is influenced by determining the asymptotic peak sidelobe level and the dynamics range. In addition, the influence of the high-speed target on main lobe broadening and the performance degradation of adaptive filters is investigated. Finally, extending of radar dynamic range with the proposed FFL-APCR algorithm is shown in various conditions and its performance evaluated by mean square error criteria. Where return signals coincide with the transmission of a PULSE, PULSE eclipsing can occur which results in detection performance loss. The mismatches (Doppler phase shift and PULSE eclipsing) degrades performance of sidelobes suppression algorithms. The FFL-APCR algorithm suppresses range sidelobes by using a smaller filter length and reduces the computational cost. Consequently, this algorithm should be computationally efficient (real-time) to enable the practical application of RMMSE.

Due to the growing demand for higher bandwidth, employing optical devices instead of electronic devices in data transmission systems has attracted much attention in recent years. Optical switches, modulators and wavelength converters are a few examples of the required optical devices. CMOS compatible fabrication of these devices, leads to much more growing of this technology. Optical PULSE COMPRESSION, is required for generating ultra-short PULSEs for high bandwidth optical transmission systems. In this work, we present a CMOS fabrication process compatible, integrated optical PULSE compressor. A Silicon waveguide coated by MoS2 for nonlinearity enhancement is used for self-phase modulation and a chirped Bragg grating utilizing corrugated silicon waveguides is employed to achieve the required anomalous dispersion. Low power and high COMPRESSION ratio were considered in this work. We achieved a COMPRESSION ratio of 3. 5 by using a relatively low power optical PULSE of 8W and a short waveguide length of 1mm.

In this paper, exploitation of parallel matched filters bank based on binary phase code is proposed, to overcome shift Doppler in ground based radars which use PULSE COMPRESSION technique. The mismatch loss due to target Doppler shift in radar receiver reduced by odd or even number of these parallel filters. By increasing the number of filters over target velocity axis the central Doppler frequencies of the neighbor filters approach together and consequently the overlap increases and results in the straddling loss decrease in output. Using MATLAB software, the attenuation in the output of the receiver matched filter due to airborne target velocity was analyzed and a solution to calculate minimum number of filters is proposed for minimum loss of SNR. Finally, two methods for implementation of parallel matched filters on FPGA in the airborne targets radar receiver are presented and compared.

Polyphase is a common class of PULSE COMPRESSION waveforms in the radar systems. Oppermann code is one of the used codes with polyphone pattern. After COMPRESSION, this code has little tolerant against Doppler shift in addition to its high side lobe level. This indicates that the use of Oppermann code is an unsuitable scheme to radars applications. This paper shows that the use of amplitude weighting functions improves properties of code and makes it an appropriate technique. Noticeable reduction in sidelobe and false alarm as well as the increase of the target detection ability and Doppler tolerant are the signature of amplitude weighting functions investigated and simulated in this study.

PULSE-Doppler radars typically use PULSE COMPRESSION and Doppler processing to detect moving targets through fast Fourier transforms. The conventional PULSE COMPRESSION method and the standard matched filter output for detection of small targets close to a large target do not work well, since the sidelobes of the match filter output by a large target could mask the smaller targets. Adaptive PULSE COMPRESSION resolves this issue significantly in noise. However, the fast targets induce Doppler phase shift in the received signal frequency, in which cause mismatch between the received signal and the transmitted signal. Consequently, the Signal to Noise Ratio is reduced. Whereas the matched filter in the radar receiver is only adapted to the transmitted signal version and its output will be wasted due to non-matching with the received signal from the environment. Adaptive PULSE COMPRESSION is generally applied with a single PULSE in alone noise environment, but in the presence of strong clutter it is required to several return PULSEs. In this paper, to supply these PULSEs, in a radar transmitter equipped with adaptive PULSE COMPRESSION, waveforms diversity are generated by random frequency hopping in step frequency waveform. The simulation results of the detection of masked moving targets are compared with other conventional methods.

In this paper, we investigate the detection of masked weak moving targets in the adjacent fast strong target by using FAPC algorithm. The matched filter of conventional PULSE COMPRESSION radars induces range sidelobes in surrounding a target with high SNR that could mask the smaller targets. The mismatch created in received signal by Doppler phase shift, degrades APC filter performance in side lobe suppression. In this paper, the FFL-FAPC algorithm is proposed to reduce the range side lobes using the RMMSE estimator in its post-processing method. In various scenarios, we will investigate the detection of masked targets in comparsion with previous methods. Simulation results show that the FFL-FAPC algorithm reduce significantly of computational cost, in addition to provides improved Doppler robustness.