Methods for determining a relative distance between a first antenna element and a second antenna element each being part of an antenna array, antenna arrays and vehicle

An embodiment of a method 100 for determining a relative distance r between a first antenna element and a second antenna element each being part of an antenna array, comprises transmitting 101 a first radar signal, with a first frequency f1, by the first antenna element and receiving 102 a first receive signal, related to the first radar signal, by the second antenna element. The method 100 further comprises demodulating 103 the first receive signal based on the first radar signal to obtain a first intermediate signal s1 having a first phase ϕ1. Further, the method 100 comprises transmitting 104 a second radar signal, with a second frequency f2, by the first antenna element and receiving 105 a second receive signal, related to the second radar signal, by the second antenna element. The method 100 further comprises demodulating 106 the second receive signal based on the second radar signal to obtain a second intermediate signal s2 having a second phase ϕ2. Further, the method 100 comprises determining 107 the relative distance r based on the first phase ϕ1 and the second phase ϕ2.