University of Twente Student Theses
Reducing the dynamicrange of analog-to-digital converter in FMCW harmonic radars
Sadykov, Askar (2024) Reducing the dynamicrange of analog-to-digital converter in FMCW harmonic radars.
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| Abstract: | Frequency Gain Control (FGC), an equivalent of Sensitivity Time Circuit (STC) in Frequency-Modulated-Continuous-Wave (FMCW) radars, stands for applying a highpass filter (HPF) with the slope matching the negative slope of the path loss to the beat signal, given direct relation of its frequency to the target range. This technique primarily takes care of two issues: ground clutter and saturation of the receiver. In harmonic FMCW radars, the ground clutter is resolved by separating the receiver from the transmitter by frequency. Nevertheless, the problem of saturation remains. Apart from preventing the saturation of the receiver, FGC can reduce the dynamic range of the analog-to-digital converter (ADC), allowing for lower resolution of the ADC. In radars, due to the path loss, the magnitude of the received signal coming from further distances can be smaller than the quantization step of the ADC at the receiver’s side. To be able to detect the target at such distances, the resolution must be high. The primary goal of this research was to reduce the dynamic range of the ADC with the help of FGC, to allow for a cheaper ADC with lower resolution. This paper provides the methodology and the results of the computer simulations in Matlab that show how FGC affects the power of the received signal for a harmonic FMCW radar. Also, a comparison to a conventional FMCW radar is made. This research shows that applying FGC to ease the ADC resolution requirement successfully restricts the power of the received signal to a level that does not exceed the ADC’s dynamic range. This paper argues that, for linear radars, a second-order HPF should be used. And for harmonic systems, third-order characteristics apply for low-power applications, whereas for high-power applications, a second-order filter with the calibration of the cut-off frequency is a better choice. |
| Item Type: | Essay (Bachelor) |
| Faculty: | EEMCS: Electrical Engineering, Mathematics and Computer Science |
| Subject: | 53 electrotechnology |
| Programme: | Electrical Engineering BSc (56953) |
| Link to this item: | https://purl.utwente.nl/essays/103221 |
| Export this item as: | BibTeX EndNote HTML Citation Reference Manager |
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