Ultra-wideband Pulse Research Articles

Prediction method of Ultra-wideband electromagnetic pulse coupling in slotted cavity

With the develofpment of UWB electromagnetic pulse radiation systems, people are paying more and more attention to its serious threat to electronic equipment. The effect of UWB electromagnetic pulse has also become an important content in the field of electromagnetic compatibility. In an UWB radiation system, the distance between the device under test and the transmitting antenna is different, and the radiation field received is also different. Therefore, in actual tests, the test body is often placed at different distances from the antenna to perform multiple measurements to obtain test data as required. Based on this, this article takes the cavity as an example, and proposes a method of using the system transfer function to predict the response of the impulse field inside the cavity to simplify the test and quickly obtain the test data. Firstly, the impulse field response of a certain point with and without a cavity is measured respectively, and then the time domain response is inversely Fourier transformed to obtain the frequency domain transfer function of the test body. Finally, using the transfer function to convolute with the field to be measured, the response of the impulse field inside the cavity can be predicted under the condition of the field to be measured. It is verified by experiments that this method can better predict the response of the impulse field inside the cavity under different distance conditions, and has the characteristics of simple calculation and good prediction effect. At the same time, the transfer function obtained by this method can be used to predict the arbitrary impulse field response of the cavity in its frequency range.

An experimental research of the ultra-wideband pulse propagation in a transdirectional coupler based on coupled striplines

An experimental research of the ultra-wideband pulse propagation in a transdirectional coupler based on coupled striplines

Design and Device Mismatch Analysis of CSS–UWB Pulse Generator

This paper presents the design of a Chirp Spread Spectrum (CSS), ultra-wideband (UWB), pulse generator (PG) and device mismatch impact on its performance. The proposed CSS-PG is built using a differential ring oscillator (RO) controlled by a ramp generator, allowing varying linearly the pulse frequency with time over the CSS pulse duration. Device mismatches and random variations during integrated circuit manufacturing are the most critical imperfections in high precision differential UWB voltage controlled RO circuit. These mismatches lead to behavioral variations of the PG. The proposed CSS-UWB-PG is designed and analyzed using CMOS 0.18[Formula: see text][Formula: see text]m technology. The CSS-PG presents an output swing of 266[Formula: see text]mV Vpp for 20[Formula: see text]nsec and consumes 1.72[Formula: see text]mW for a PRF of 10[Formula: see text]MHz. The simulated PSD covers the UWB low band from 3[Formula: see text]GHz to 5[Formula: see text]GHz and complies with the FCC regulations. For [Formula: see text] mismatch, the simulation results show a maximum relative accuracy on oscillation frequency and phase noise of 3.43% and 6.9%, respectively. Monte Carlo and process simulation are performed to study the impact of the random parameter variation on this CSS-PG. Theses simulations show the robustness of the proposed design as the PG PSD is still inside the FCC-UWB mask and its bandwidth is greater than 500[Formula: see text]MHz.

Integration and Prototyping of a Pulsed RF Oscillator with an UWB Antenna for Low-Cost, Low-Power RTLS Applications.

The goal of this paper is to present a compact low-cost and low-power prototype of a pulsed Ultra Wide Band (UWB) oscillator and an UWB elliptical dipole antenna integrated on the same Radio Frequency (RF) Printed Circuit Board (PCB) and its digital control board for Real Time Locating System (RTLS) applications. The design is compatible with IEEE 802.15.4 high rate pulse repetition UWB standard being able to work between 6 GHz and 8.5 GHz with 500 MHz bandwidth and with a pulse duration of 2 ns. The UWB system has been designed using the CST Microwave Studio transient Electro-Magnetic (EM) circuit co-simulation method. This method integrates the functional circuit simulation together with the full wave (EM) simulation of the PCB’s 3D model allowing fast parameter tuning. The PCB has been manufactured and the entire system has been assembled and measured. Simulated and measured results are in excellent agreement with respect to the radiation performances as well as the power consumption. A compact, very low-power and low-cost system has been designed and validated.

Analysis of typical PLC pulses for sensing high-impedance faults based on time-domain reflectometry

This paper focuses on a comprehensive analysis of typical power line communication (PLC) pulses for sensing high impedance faults in power distribution networks (PDNs) when the pulse compression time-domain reflectometry (TDR) system applies. In this sense, closed-form expressions for the PLC pulses, namely Hermitian symmetric orthogonal frequency-division multiplexing (HS-OFDM), impulsive ultra-wideband (UWB), and chirp spread spectrum (CSS), and their corresponding autocorrelation functions are presented. Also, parameters based on radar theory (e.g., range resolution, pulse compression ratio, reflectogram distortion, and maximum unambiguous range) are introduced to evaluate the usefulness of these PLC pulses for providing proper TDR measurements (reflectograms). A comparative numerical analysis considering frequency bands that comprise narrowband and broadband PLC systems, with a highlight on well-established regulatory constraints, is discussed. Numerical results show that the use of UWB pulses yields a larger number of reflectograms in a given time interval, while HS-OFDM and CSS pulses provide higher reflectogram quality and better resolution, under the same conditions. Also, narrowband PLC systems are suitable for the majority of PDNs, with the use of broadband PLC ones left for attaining high resolutions at short distances.

A 27 dB Sidelobe Suppression, 1.12 GHz BW−10dB UWB Pulse Generator With Process Compensation

This brief presents an on-off keying (OOK) driven impulse radio ultra-wideband (IR-UWB) pulse generator (PG) for 3-5 GHz applications, featuring high sidelobe suppression (SLS), large bandwidth ( BW <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-10dB</sub> ), and robustness against process variations. To eliminate the need for a dedicated off-chip pulse-shaping filter, a transistor-sizing-based pulse shaping scheme is adopted to generate a broadband pulse with a triangular envelope, ensuring enhanced SLS with extended signal bandwidth. The proposed process compensating circuit mitigates the effects of process variations on the propagation delay of the logic gates to provide stable pulse timing characteristics. Implemented in 65-nm CMOS process, the prototype PG provides a UWB pulse with an amplitude of 634 mV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pp</sub> , BW <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-10dB</sub> of 1.12 GHz, and 27 dB SLS, while occupying a total chip area of 964 μm × 669 μm. The proposed PG provides enhanced pulse characteristics with modest energy consumption among the reported works. Based on the proposed figure-of-merit considering the SLS and quality of pulse, the PG in this work shows a competitive FOM of 3.36×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup> .

Simulation of Interference Effects of UWB Pulse Signal to the GPS Receiver

Ultra-wideband (UWB) pulse signal has an extremely narrow pulse width and wide frequency bandwidth, which overlaps with the operating frequency band of Global Position System (GPS) receivers, posing a potential threat to their performance. In response to this problem, through mathematical analysis and software simulation, the effects of UWB pulse signal under time-hopping-pulse position modulation (TH-PPM) on the performance of GPS receivers were studied. First, the expression and waveform of the UWB pulse signal were analyzed in the time-frequency domain, and it is concluded that the pulse repetition frequency (PRF) mainly affects the discrete spectrum of the UWB signal and the TH code period mainly affects the continuous spectrum. On this basis, the simulation on the power spectral density (PSD) of GPS signal and UWB signal under different pulse parameters was represented, from which a conclusion can be drawn that the PRF is the main factor impacting the PSD of the GPS signal. Furthermore, this paper analyzed the degradation of GPS receiver equivalent carrier-to-noise ratio (C/N0) and C/A code demodulation bit error rate (BER) under UWB interference, which are the crucial evaluating indicators of GPS signal quality. Eventually, we theoretically calculated the minimum interference level of the UWB interference signal to the GPS receiver, providing a theoretical reference for reducing the interference effects of UWB pulse signal on the performance of GPS receivers.

Измерение водного эквивалента, средней плотности и высоты слоисто-неоднородного снежного покрова СНП электромагнитными импульсами. Теоретическое исследование.

Abstract. In this work, the processes of interaction of ultra-wideband (UWB) pulses with the duration of 0.47 ns with layered dry snow cover are theoretically investigated. The layered structure of the snow cover was modeled on the basis of experimental data on the height and density profile of the snow cover, which were measured in field on the test plot of an agricultural field in the area of the village. Minino, Krasnoyarsk Territory from November 12, 2020 to March 21, 2021. It is shown that the snow water equivalent (SWE) can be estimated from the time delay of the pulse reflected from the snow-soil interface with the coefficient of determination (R2) R2 = 0.98 and the root-mean-square error (RMSE) RMSE = 5.6 mm in the case of thickness from 4-6 to 39cm and an average density from 0.21 to 0.37 g/cm3 of snow cover. It is shown that the average density of snow cover linearly depends on the amplitude ratio of impulses reflected from the boundaries, snow-soil and air-snow (R2 = 0.55, RMSE = 0.04 g/cm3). The established dependencies make it possible to estimate the height of the snow cover with R2 = 0.95, RMSE = 2.9 cm. The accuracy of the proposed method for measuring SWE, average density and height of snow cover should be further investigated depending on variations in temperature, moisture, density, and texture of frozen soil, as well as under different moisturized conditions of snow. The obtained results are particular relevance in connection with the possibility of implementing this remote sensing method from the UAV, which opens up the prospects for creating a technology for UWB radar mapping of the main characteristics of the snow cover for use in precision farming systems.

A compact narrow-width combined antenna for the radiation of the UWB electromagnetic pulses.

In this article, a Narrow-Width Combined Antenna (NWCA) is proposed for the compact design of high-power ultra-wideband (UWB) systems. The dependence of performances on three dimensions of the combined antenna is investigated so as to minimize its size with a given excitation. It indicates that the working process of the combined antenna can be divided into two stages: (1) energy transmitted from the feeding point to the aperture by the TEM horn structure, and during this stage, the passband is determined by the effect of the impedance taper, which is related to the length and aperture impedance of the antenna, and (2) energy radiated to the free space from the aperture, during which the height of the aperture is the dominant factor. Therefore, the three dimensions of the combined antenna can be appropriately adjusted to make the antenna more compact. Thus, the NWCA is designed by reducing the width and making a slight compensation in height and/or length. Compared with the conventional cubic antenna, the aperture area of the developed NWCA is reduced by 47%, whereas the amplitude of the radiating field only reduces by 2.5% with the given pulsed excitation at the cost of a slight decrease in the pulse duration. It demonstrates that the NWCA is an effectively compact design for the combined antenna in the application of the radiation of the high-power UWB pulse.

Ultra-Wideband Pulse Radar Mounted on an Unmanned Aerial Vehicle for the Monitoring of Moving Objects

Ultra-Wideband Pulse Radar Mounted on an Unmanned Aerial Vehicle for the Monitoring of Moving Objects

Numerical Analysis of the Localization of Pulmonary Nodules during Thoracoscopic Surgery by Ultra-Wideband Radio Technology

Worldwide, lung cancer is one of the most common causes of cancer-related death. Detected by computer tomography, it is usually removed through thoracoscopic surgery. During the surgery the lung collapses requiring some strategies to track or localize the new position of the lesion. This is particularly challenging in the case of minimally invasive surgeries when mechanical palpation is not possible. Here we undertake a preliminary study with numerical analysis of an ultra-wideband (UWB) radio technology which can be employed directly during thoracoscopic surgery to localize deep solitary pulmonary nodules. This study was conducted through Finite Difference Time Domain (FDTD) simulations, where a spherical target mimicking a nodule located between 1 and 6 cm of depth and an UWB pulse at several frequencies between 0.5 and 5 GHz was used for localization. This investigation quantifies the influence of several parameters, such frequency, lesion depth, and number of acquisitions, on the final confocal image used to locate a cancer in the lung tissue. We also provide extensive discussion on several artifacts that appear in the images. The results show that the cancer localization was possible at operational frequencies below 1 GHz and for deep nodules (&gt;5 cm), while at lower depths and higher frequencies several artifacts hindered its detection.

Research on blocking interference for digital radio station under UWB EMP

In order to make certain of the blocking impact of the ultra-wideband electromagnetic pulse (UWB EMP) on a radio communication station, an EMP injection test was conducted to study the blocking interference of a digital radio station under a step pulse train and double exponential pulse train. Combined with waveform parameters such as the pulse repetition rate (PRR), the concept of influence time when the UWB EMP was irradiated on the equipment under test (EUT) was introduced, and the model was established. According to the experimental results, the blocking impact of the EUT under the UWB EMP depended on factors such as waveform, PRR, and amplitude. The relationship between the PRR and the sensitive bit error rate could be determined by the effect test. In the case of a low PRR, the sensitive voltage threshold of the EUT was irrelevant to the PRR, and the effect was the monopulse effect. When the PRR reached above the reciprocal of the influence time, the sensitive voltage threshold of the EUT decreased with the increase in the PRR, which conformed to the cumulative multiple pulse effects.

Ultra-wideband ultra-short pulse communication system

Problem statement. The development and design of radio communication systems with enhanced structural and energy stealth properties are of the greatest interest in modern radio engineering. One method of implementing such radio systems is the use of ultra-wideband signals. Despite advances in radio engineering theory, the development and design of ultra-wideband radio systems are at the initial stage. The results obtained in this subject area are not systematized, limiting their practical application and indicating the relevance of the chosen research problem.The study's objective is to formalize an approach to the design and performance assessment of ultra-wideband radio systems based on statistical radio engineering methods. Bringing the obtained theoretical solutions to the level of practical implementation in a radio station layout.Results. The analysis of available theoretical and practical solutions in the subject area of ultra-wideband radio systems is carried out. The principles of development and evaluation taking into account the characteristics of radio equipment elements are justified. A model of an ultra-wideband radio pulse is presented. The requirements of guiding documents are summarized, based on which the requirements for radio equipment are clarified. The criteria for the formation and processing of ultra-wideband signals are determined. An approach to controlling the parameters of the applied signals is considered. The criterion of increasing the efficiency of radio systems is justified. An approach to calculating the size of the pulse packs defining the signal symbols is developed. Analytical calculations are presented following the developed approach.Practical implications. The authors developed a model of an ultra-wideband radio station based on LLC Scientific Production Enterprise "New Telecommunications Technologies". The obtained practical solutions can be used in the field of practical implementation of ultra-wideband radio communication systems

Ultra-Wideband Pulse Radar with Discrete Stroboscopic Receiver for Detection of Small Targets Behind Dielectric Obstacles

Abstract Increasing requirements in the field of security, in particular in the transport sector, the rescue work, the inviolability of private property and others urged to research work in the field of radar monitoring people, vehicles or other objects in the environment that not allow make so using the most popular and available technology for production and analysis of video images. These conditions of poor visibility, or even lack thereof, are darkness, bad weather, smoke, dust, wall (roof) buildings and the vehicle body. Existing instruments and special equipment occupy a certain niche in this area, mainly for counter-terrorism operations. However, such equipment is not readily available and extremely high price. In the paper presented research is development of the group’s existing radar technology in the field of location through opaque obstacles.

A Local Oscillator Phase Compensation Technique for Ultra-Wideband Stepped-Frequency Continuous Wave Radar Based on a Low-Cost Software-Defined Radio.

The paper discusses a way to configure a stepped-frequency continuous wave (SFCW) radar using a low-cost software-defined radio (SDR). The most of high-end SDRs offer multiple transmitter (TX) and receiver (RX) channels, one of which can be used as the reference channel for compensating the initial phases of TX and RX local oscillator (LO) signals. It is same as how commercial vector network analyzers (VNAs) compensate for the LO initial phase. These SDRs can thus acquire phase-coherent in-phase and quadrature (I/Q) data without additional components and an SFCW radar can be easily configured. On the other hand, low-cost SDRs typically have only one transmitter and receiver. Therefore, the LO initial phase has to be compensated and the phases of the received I/Q signals have to be retrieved, preferably without employing an additional receiver and components to retain the system low-cost and simple. The present paper illustrates that the difference between the phases of TX and RX LO signals varies when the LO frequency is changed because of the timing of the commencement of the mixing. The paper then proposes a technique to compensate for the LO initial phases using the internal RF loopback of the transceiver chip and to reconstruct a pulse, which requires two streaming: one for the device under test (DUT) channel and the other for the internal RF loopback channel. The effect of the LO initial phase and the proposed method for the compensation are demonstrated by experiments at a single frequency and sweeping frequency, respectively. The results show that the proposed method can compensate for the LO initial phases and ultra-wideband (UWB) pulses can be reconstructed correctly from the data sampled by a low-cost SDR.

Modern approaches to ensure traceability of fast electrical pulse processes measurements

The necessity of improving the State primary special standard for a unit of pulsed electric voltage GET 182-2010 is substantiated on the basis of an electro-optical sampling system. Approaches to ensure the uniformity of pulse measurements are proposed, aimed at developing a new system of measurements traceability of pulsed signals parameters to the units of the International System of Units, as well as ensuring independent reproduction of reference ultra-wideband electrical pulses. The considered approaches can be used to work on GET 182-2010 improvement. The main tasks of further research in the direction of creating a domestic electro-optical sampling system are formulated.

Detection of Chaotic Radio Pulses Using an Ensemble of Envelope Detectors

In this paper, we study the possibility of detecting ultrawideband chaotic radio pulses using an ensemble of incoherent receivers based on envelope detectors. An analytical expression for the reception error probability as a function of the signal-to-noise ratio at the input of the envelope detector is obtained. The sensitivity of radio pulse detection (in terms of the signal-to-noise ratio) is shown to improve in proportion to the number of detectors.

Измерение мощности сверхширокополосного хаотического сигнала для решения задач определения расстояния и позиционирования

A method increasing the accuracy of distance measurements using an ultra-wideband chaotic radio pulses, intended for application in wireless sensor networks is proposed. It was shown that the relative error of distance measurement in the experimental test bench is within 5-9%.

IR-UWB Chipless RFID Reader Based on Frequency Translation Technique for Decoding Frequency-Coded Tags

The impulse radio ultra-wideband (IR-UWB) reader is the most promising technique to interrogate a frequency-coded chipless radio frequency identification (RFID) tag. However, challenges of receiving an ultra-wideband (UWB) pulse, such as complexity, high-noise bandwidth, low reading speed, and high cost, are yet to be addressed in IR-UWB readers. A combined solution based on an IR-UWB transmitter and a frequency translation (FT) method in the receiver is presented in this article. The tag is interrogated by a broadband pulse (3.1-10.6 GHz). In the receiver, instead of processing the entire wideband backscattered pulse in one run, the new architecture transposes the spectrum of the backscattered pulse to a 150-MHz intermediate frequency (IF) band. Hence, the noise bandwidth, cost, and complexity of the receiver are reduced significantly. Since the reading range plays a decisive role in reducing the complexity and cost, a detailed study of the design parameters of the reader, affecting the detection range, is performed. Then, a low-cost and straightforward reader is implemented, based on the outcomes of the parameters' study. It is shown that the reading range of the reader is competitive with that of the state-of-the-art readers and vector network analyzer (VNA), while the complexity, reading time, and cost are dropped.

A Compact High-Power Ultra-Wideband Bipolar Pulse Generator

A compact high-power ultra-wideband bipolar pulse generator based on a modified Marx circuit is designed, which is mainly composed of a primary power supply, Marx generator, sharpening and cutoff subnanosecond spark gap switches, and coaxial transmission lines. The Marx generator with modified circuit structure has thirty-two stages and is composed of eight disk-like modules. Each module consists of four capacitors, two spark gap switches, four charging inductors, and a mechanical support. To simplify the design of the charging structure and reduce the number of switches, four groups of inductors are used to charge the capacitors of the Marx generator, two of which are used for positive voltage charging and the other two for negative voltage charging. When the capacitor of each stage is charged to 35 kV, the maximum output peak voltage can reach 1 MV when the Marx generator is open circuit. The high-voltage pulse generated by the Marx generator charges the transmission line and forms a bipolar pulse through sharpening and cutoff switches. All transmission lines used for bipolar pulse generation have an impedance of 10 Ω. When the 950 kV pulse voltage generated by the Marx generator is fed into the transmission line, the bipolar pulse peak voltage can reach 390 kV, the center frequency of the pulse is about 400 MHz, and the output peak power is about 15.2 GW.