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Calibration to Mitigate Near-Field Antennas Effects for a MIMO Radar Imaging System^{ †}

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## Abstract

**:**

## 1. Introduction

## 2. Radar Imaging System

## 3. Antennas Effects and Shift Modelling

## 4. Calibration Scheme and Results

## 5. Conclusions

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 3.**Received signals measured at the antenna port with the effects of imperfection in ${S}_{11}$ and proximity coupling.

**Figure 9.**Reconstructed images with the DoA dependence effect based on measurement channels (

**a**) C11, (

**b**) C22 and (

**c**) the estimation of differential parameter of the shift.

**Figure 10.**Reconstructed images with DoA dependence effect based on measurement channels (

**a**) C12, (

**b**) C21 and (

**c**) all four channels.

**Figure 11.**Reconstructed images with DoA dependence calibration based on measurement channels (

**a**) C11, (

**b**) C22 and (

**c**) estimation of angle between the two lines.

**Figure 12.**Reconstructed images with DoA dependence calibration based on measurement channels (

**a**) C12, (

**b**) C21 and (

**c**) all four channels.

**Figure 13.**Angle between the two lines estimated from the reconstructed images vs. the angle $-{\alpha}_{a}$ used to compensate for the differential parameter ${\alpha}_{a}$ of the model.

**Figure 14.**Testing the system with (

**a**) “TUD” pattern and results (

**b**) with DoA dependence calibration and (

**c**) without DoA dependence calibration based on measurement data of all of four channels.

Parameters | Values |
---|---|

Antennas space (${s}_{0}$) | $180\mathrm{mm}$ |

System distance (${r}_{0}$) | $690\mathrm{mm}$ |

Angular step size ($\Delta \beta $) | ${1.5}^{\xb0}$ |

Rotating step number | $240$ |

Turntable tolerance | $\pm {0.1}^{\xb0}$ |

Antenna size (L × W) | $130\times 120{\mathrm{mm}}^{2}$ |

System bandwidth | $10\mathrm{MHz}\u201339.9\mathrm{GHz}$ |

Frequency step | $10\mathrm{MHz}$ |

Transmitting power | $10\mathrm{dBm}$ |

Channel | Antenna Mode |
---|---|

C11 | Tx: Ant.1, Rx: Ant.1 |

C12 | Tx: Ant.1, Rx: Ant.2 |

C21 | Tx: Ant.2, Rx: Ant.1 |

C22 | Tx: Ant.2, Rx: Ant.2 |

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**MDPI and ACS Style**

Hoang, H.; John, M.; McEvoy, P.; Ammann, M.J. Calibration to Mitigate Near-Field Antennas Effects for a MIMO Radar Imaging System. *Sensors* **2021**, *21*, 514.
https://doi.org/10.3390/s21020514

**AMA Style**

Hoang H, John M, McEvoy P, Ammann MJ. Calibration to Mitigate Near-Field Antennas Effects for a MIMO Radar Imaging System. *Sensors*. 2021; 21(2):514.
https://doi.org/10.3390/s21020514

**Chicago/Turabian Style**

Hoang, Ha, Matthias John, Patrick McEvoy, and Max J. Ammann. 2021. "Calibration to Mitigate Near-Field Antennas Effects for a MIMO Radar Imaging System" *Sensors* 21, no. 2: 514.
https://doi.org/10.3390/s21020514