scholarly journals A New Demodulation and Modulation Method Designed for FMCW Radar

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Wei Shen ◽  
Biyang Wen

An efficient demodulation method designed for FMCW (Frequency-Modulated Continuous Wave) radar is presented. It is a kind of modified DFT (IDFT) algorithm; the spectrum segment of interest can be easily extracted from the original signal without calculating the whole DFT/FFT. It provides fast demodulation and extraction of desired frequency bands in our HFSWR (High-Frequency Surface Wave Radar) system. The proposed approach enhances the performances of radar system and reduces the computing complexity. The new structure could also be inversely used for signal modulation. And also arbitrary sampling rate conversion could be achieved with the combination of forward and backward structure.

2018 ◽  
Vol 10 (2) ◽  
pp. 207-215 ◽  
Author(s):  
Werner Scheiblhofer ◽  
Reinhard Feger ◽  
Andreas Haderer ◽  
Andreas Stelzer

AbstractWe present the realization of an frequency-modulated continuous-wave radar target simulator, based on a modulated-reflector radar system. The simulator, designed for the 24 GHz frequency band, uses low-cost modulated-reflector nodes and is capable to simultaneously generate multiple targets in a real-time environment. The realization is based on a modular approach and thus provides a high scalability of the whole system. It is demonstrated that the concept is able to simulate multiple artificial targets, located at user-selectable ranges and even velocities, utilized within a completely static setup. The characterization of the developed hardware shows that the proposed concept allows to dynamically and precisely adjust the radar cross-section of each single target within a dynamic range of 50 dB. Additionally, the provided range-proportional target frequency bandwidth makes the system perfectly suitable for fast and reliable intermediate frequency-chain calibration of multi-channel radar systems. Within this paper we demonstrate the application of the concept for a linear sweeped frequency-modulated continuous-wave radar. The presented approach is applicable to any microwave-based measurement system using frequency differences between transmit- and receive signals for range- and velocity evaluation, such as (non-)linear sweeped as well as pure Doppler radar systems.


2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Shang Shang ◽  
Kangning He ◽  
Zhaobin Wang ◽  
Xuguang Yang

In HFSWR (high-frequency surface-wave radar) system, the detection performance is impacted seriously by ionospheric clutter. Frequency selection is an effective method to avoid the effect of ionospheric clutter. The key to the method is the stationarity of ionospheric clutter over a period of time. This paper mainly researches the stationary time statistical property of the ionospheric clutter. A large number of real data including ionospheric clutter in HFSWR are processed and analyzed. It shows that ionospheric clutter in HFSWR has the characteristics of approximate stationarity within a period of time.


2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Sven Schellenberger ◽  
Kilin Shi ◽  
Tobias Steigleder ◽  
Anke Malessa ◽  
Fabian Michler ◽  
...  

Abstract Using Radar it is possible to measure vital signs through clothing or a mattress from the distance. This allows for a very comfortable way of continuous monitoring in hospitals or home environments. The dataset presented in this article consists of 24 h of synchronised data from a radar and a reference device. The implemented continuous wave radar system is based on the Six-Port technology and operates at 24 GHz in the ISM band. The reference device simultaneously measures electrocardiogram, impedance cardiogram and non-invasive continuous blood pressure. 30 healthy subjects were measured by physicians according to a predefined protocol. The radar was focused on the chest while the subjects were lying on a tilt table wired to the reference monitoring device. In this manner five scenarios were conducted, the majority of them aimed to trigger hemodynamics and the autonomic nervous system of the subjects. Using the database, algorithms for respiratory or cardiovascular analysis can be developed and a better understanding of the characteristics of the radar-recorded vital signs can be gained.


2013 ◽  
Vol 329 ◽  
pp. 338-343
Author(s):  
Tian Jiao Fu ◽  
Li Guo Zhang ◽  
Jian Yue Ren

The azimuthal measurements of the high frequency ground wave radar are poor in an actual environment, which can cause the plots highly decentralized and damage the formation of the over-the-horizon tracks. To solve the problem, a new radar system is proposed to triangulate target tracks using range and Doppler measurements only. On the basis of the analysis of the characteristics of the range-finding location, a multi-target tracking algorithm under non-clutter condition is given in this paper, which further improves the tracking algorithm of this system. Simulation results show the effectiveness of this method.


2012 ◽  
Vol 253-255 ◽  
pp. 1410-1417 ◽  
Author(s):  
Zhi Gang Li ◽  
Qiong Chan Gu

For frequency modulate continuous wave radar, it is necessary and difficult to search the pairs of beat frequencies in an up-chirp mode and a down-chirp mode t o measure range and velocity of multiple targets. However, the inherent problem of FMCW radar is multiple targets detection. False targets can appearance because of mistaking the combination of these beat frequencies. A novel waveform named double-slope symmetrical saw-tooth wave is proposed and its corresponding algorithm is also introduced to resolve the problem of multiple targets detection for automotive anti-collision radar. Computer simulation results and theoretical analysis prove that the method is effective and practical for multiple targets detection in intelligence transportation system.


2013 ◽  
Vol 5 (3) ◽  
pp. 409-417 ◽  
Author(s):  
Jochen O. Schrattenecker ◽  
Andreas Haderer ◽  
Günther Reinthaler ◽  
Andreas Stelzer

In this paper, we present the results of using a frequency-stepped continuous-wave radar system to estimate the position of overlapping and electrically good conductive plates. We especially focus on polarimetric scattering effects caused by the step of a lap joint, which is a common welding-geometry. To model the step's contribution to the overall scattered signal, we use a two-dimensional combined field integral equation (CFIE) approach. For demonstrating its practical applicability, the implemented scattering model is verified by measurements. To emphasize the improvements of position estimation by using a CFIE approach, the outcomes of the model are compared to a commonly used point scattering model. Finally, the numerical signal is utilized to precisely estimate the position of the lap joint.


2019 ◽  
Vol 19 (2) ◽  
pp. 38
Author(s):  
Hana Pratiwi ◽  
Mujib R. Hidayat ◽  
A. A. Pramudita ◽  
Fiky Y. Suratman

Frequency Modulated Continuous Wave (FMCW) radar system has been developed and applied for various needs. Based on the conventional FMCW radar concept, a large bandwidth is needed to detect small displacements in the chest wall or abdomen related with respiratory activity. To overcome the need for large bandwidths in detecting vital respiratory signs, several improvements to the FMCW system are proposed in this paper. The phase-detection concept has been elaborated in improving the capability of FMCW to detect the small displacement. In developing multi-target detection capability, range detection capability through beat frequency output needs to be combined with the phase-detection method. Theoretical and simulation studies were performed to investigate the concept of combining range detection and phase detection for detecting respiration on multi-target. The results show that the proposed method is well-performed in detecting the multi-target respiration in high noise reflection.


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