Probe-receiver coupling in external calibration systems

On-line calibration systems with near-field probes are an attractive approach for large-size DBF arrays. In order to improve the calibration accuracy, a model of the coupling between the receiver patch and the calibration monopole probe is developed further in this contribution. A Fourier-based approximation of the radiation characteristic of the patch is proposed as a compromise between accuracy and computational effort. A planar array is built to validate the proposed concept. A phase error of 1.5° and an amplitude deviation of 0.8 dB are achieved in the experiments.