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You searched for subject:(FMCW radars). Showing records 1 – 3 of 3 total matches.

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Delft University of Technology

1. Sanka, Sasanka (author). Radar to radar interference for 77GHz automotive radar.

Degree: 2017, Delft University of Technology

Automotive radar is a key element in Advanced Driver Assistance Systems (ADAS). With the growth of Automotive industry, there is a high demand for the sensors used in assisting systems. As the number of sensors increases, probability that these systems being in close proximity will also increase. This will lead to situations where in multiple radar sensors will be operating in close proximity, this might lead to a sub-optimal performance of our radar system. Currently FMCW radar systems are most prevalent in the automotive radar market. For FMCW systems, interference mitigation techniques exist in time domain, frequency domain, polarization domain and etc. Most of these techniques insiston detecting and identifying the interference before mitigating it. In this thesis, we consider a FMCW radar system and first develop a MATLAB model for the three most important interference scenarios namely Continuous Wave(CW), FrequencyModulatedContinuousWave (FMCW) and PhaseModulatedContinuousWave (PMCW). We propose a signal model where interference can be localized over the beat signal, then we systematically study how interference can be detected. As a result, we will detect the interference even if the power level of the interferer is lower than the power level of the received reflected signal. Post detection of interference,we suggest a technique to identify the interference by estimating the slope from the detected interference samples. Starting with a simple existing mitigation technique, we look at how to mitigate the interference and suggest enhancements that can be done for these techniques post detection and identification. Considering a worst case scenario of interference being completely in band to the transmitted signal, we propose a novel avoidance technique which will also predict the bandwidth of the interferer. As a result we will be able to shift the center frequency of the transmitter to avoid the interferer. Finally we propose another novel time domain mitigation technique where in without detecting or identifying the interferer, we will mitigate the interference and compare the gain of Signal to Interference plus Noise Ratio (SINR) achieved by using this technique. Advisors/Committee Members: Uysal, Faruk (mentor), Yarovyi, Alexander (graduation committee), Janssen, Gerard (graduation committee), Jansen, Feike (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: FMCW radars; Interference; Detection; Identification; mitigation

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APA (6th Edition):

Sanka, S. (. (2017). Radar to radar interference for 77GHz automotive radar. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:6f4231ff-49ce-4f46-944a-3c15f86c50b4

Chicago Manual of Style (16th Edition):

Sanka, Sasanka (author). “Radar to radar interference for 77GHz automotive radar.” 2017. Masters Thesis, Delft University of Technology. Accessed November 29, 2020. http://resolver.tudelft.nl/uuid:6f4231ff-49ce-4f46-944a-3c15f86c50b4.

MLA Handbook (7th Edition):

Sanka, Sasanka (author). “Radar to radar interference for 77GHz automotive radar.” 2017. Web. 29 Nov 2020.

Vancouver:

Sanka S(. Radar to radar interference for 77GHz automotive radar. [Internet] [Masters thesis]. Delft University of Technology; 2017. [cited 2020 Nov 29]. Available from: http://resolver.tudelft.nl/uuid:6f4231ff-49ce-4f46-944a-3c15f86c50b4.

Council of Science Editors:

Sanka S(. Radar to radar interference for 77GHz automotive radar. [Masters Thesis]. Delft University of Technology; 2017. Available from: http://resolver.tudelft.nl/uuid:6f4231ff-49ce-4f46-944a-3c15f86c50b4


Delft University of Technology

2. van der Geugten, Gerald (author). Predicting the sea surface from high resolution multi-beam FMCW radar data.

Degree: 2020, Delft University of Technology

In this thesis a deterministic wave model is used to reconstruct and predict the sea surface motion from FMCW (Frequency Modulated Continuous Wave) radar data, produced by Radac. The deterministic model that is used to do this is based on the linear wave theory. The radar is looking horizontally straight towards the waves in 5 separate beam directions of -40,-20,0, 20 and 40 degrees. Using the FMCW principle the backscatterd signal is converted into velocity and spatial range information. After some compensations (current for example) this velocity data can be treated as horizontal component of the orbital velocity of the wave. By using a least-squares solving approach (the trust-region reflective algorithm) on these orbital velocities and the expression that holds for them in the linear wave theory the model can be fitted to the measurements. The result of the least squares solver consists of a set of parameters for wave amplitude, phase and frequency. With these parameters the deterministic motion of the sea surface can be computed. This method is tested using artificial data and a generalized one directional case (using information from 1 beam under assumption of infinitely long-crested waves). For the experiments with artificial data consisting of waves with Hs = 2 meters (significant waveheight) the results are promising. A prediction time of 30 seconds over a range of 150 meters with an average error of 15 cm in the one directional model (fitted on 10 second data over 384 meters) can be achieved. For the multi directional model this lies between 20 and 30 seconds with an average error of 25 cm, depending on the spreading of the waves. Experiments with real data show less impressive results, an accurate reconstruction of the surface can be given, but the predictive capability is very limited.

Applied Mathematics | Applied Physics

Advisors/Committee Members: Heemink, Arnold (mentor), van der Vlugt, Rolf (mentor), Dubbeldam, Johan (graduation committee), van Gijzen, Martin (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: FMCW radars; Sea Modelling; Inverse Modelling

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

van der Geugten, G. (. (2020). Predicting the sea surface from high resolution multi-beam FMCW radar data. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:1ba166c4-2656-4f39-a250-eec61258838c

Chicago Manual of Style (16th Edition):

van der Geugten, Gerald (author). “Predicting the sea surface from high resolution multi-beam FMCW radar data.” 2020. Masters Thesis, Delft University of Technology. Accessed November 29, 2020. http://resolver.tudelft.nl/uuid:1ba166c4-2656-4f39-a250-eec61258838c.

MLA Handbook (7th Edition):

van der Geugten, Gerald (author). “Predicting the sea surface from high resolution multi-beam FMCW radar data.” 2020. Web. 29 Nov 2020.

Vancouver:

van der Geugten G(. Predicting the sea surface from high resolution multi-beam FMCW radar data. [Internet] [Masters thesis]. Delft University of Technology; 2020. [cited 2020 Nov 29]. Available from: http://resolver.tudelft.nl/uuid:1ba166c4-2656-4f39-a250-eec61258838c.

Council of Science Editors:

van der Geugten G(. Predicting the sea surface from high resolution multi-beam FMCW radar data. [Masters Thesis]. Delft University of Technology; 2020. Available from: http://resolver.tudelft.nl/uuid:1ba166c4-2656-4f39-a250-eec61258838c


Stellenbosch University

3. Meyer, Bernard. Comparing baseband and intermediate frequency FMCW radar receivers.

Degree: MSc, Electrical and Electronic Engineering, 2015, Stellenbosch University

ENGLISH ABSTRACT: Frequency modulated continuous wave (FMCW) radars have a large range of applications in the civilian and military sectors, including aircraft navigation (radio altimeters), subsurface examination, weather monitoring, and many more remote sensing applications. In general receivers have limited dynamic range. Therefore, FMCW radar receivers can saturate due to large reflections from close range targets or poor isolation between the radar system’s transmit and receive paths. It is hypothesised that certain radar receiver topologies are more suited to coping with saturation. Therefore, the intermediate frequency (IF) and the commonly-used baseband (or zero-IF) FMCW radar receiver topologies are compared in terms of component nonlinearity. Receiver saturation generates unwanted signals that can result in the detection of false targets. The study proposes that an IF receiver, under specific operating conditions, can suppress unwanted harmonics and intermodulation products (IMPs) much more effectively than an equivalent baseband receiver. A detailed IF receiver design is presented that includes a discussion on image rejection, signal quantization, anti-aliasing, and sensitivity frequency control. It is found that the IF receiver is immune to the detection of false targets caused by poor isolation between the demodulator’s local oscillator and radio frequency ports. A noise analysis shows that the IF receiver’s noise performance is potentially greater than that of an equivalent baseband receiver due to pink noise that has a 1/f power spectral density, which decreases with an increase in operating frequency. The non-linear behaviour of the IF receiver is investigated by analysing the circuit components that have the highest risk of saturation in the receiver chain. The magnitude of harmonics and IMPs are determined using an algebraic approximation of a non-linear model presented in the study. The model is used to predict under which conditions false targets will be detected. It is found that the zero-IF receiver is susceptible to distortions that are suppressible by an IF receiver. Though the application has limitations with regards to the received signal characteristics, the IF receiver has better or equivalent performance when compared to a baseband receiver.

AFRIKAANSE OPSOMMING: Frekwensie gemoduleerde kontinue golf (FMCW) radars het verskye toepassings in die privaat en militêre sektore, insluitend vliegtuig navigasie stelsels (radio altimeters), grond penetrasie radars, weer monitors, en nog vele afstandswaarnemingstoepassings. In die algemeen het ontvangers ’n beperkte dinamiese bereik. Dus kan FMCW radar ontvangers versadig as gevolg van groot weerkaatsings vanaf naby geleë teikens of swak isolasie tussen die radarstelsel se transmissie en ontvang paaie. Dit word gepostuleer dat sekere radar ontvanger topologieë meer geskik is vir die hantering van ontvanger versadiging. Daarom word die intermediêre frekwensie (IF) en die meer algemene basisband FMCW radar…

Advisors/Committee Members: De Swardt, J. B., Van der Merwe, P., Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering..

Subjects/Keywords: Baseband receivers; Frequency modulated continuous wave (FMCW) radars; Intermediate frequency (IF) design; UCTD

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Meyer, B. (2015). Comparing baseband and intermediate frequency FMCW radar receivers. (Masters Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/97858

Chicago Manual of Style (16th Edition):

Meyer, Bernard. “Comparing baseband and intermediate frequency FMCW radar receivers.” 2015. Masters Thesis, Stellenbosch University. Accessed November 29, 2020. http://hdl.handle.net/10019.1/97858.

MLA Handbook (7th Edition):

Meyer, Bernard. “Comparing baseband and intermediate frequency FMCW radar receivers.” 2015. Web. 29 Nov 2020.

Vancouver:

Meyer B. Comparing baseband and intermediate frequency FMCW radar receivers. [Internet] [Masters thesis]. Stellenbosch University; 2015. [cited 2020 Nov 29]. Available from: http://hdl.handle.net/10019.1/97858.

Council of Science Editors:

Meyer B. Comparing baseband and intermediate frequency FMCW radar receivers. [Masters Thesis]. Stellenbosch University; 2015. Available from: http://hdl.handle.net/10019.1/97858

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