Abstract: A radar system including a reference channel formed symmetrically in relation to a main channel, with a first oscillator, generating a first input signal, which is feedable to an antenna in the main channel, a reflected portion of the first input signal being feedable to a first mixer, the first input signal in the reference channel being feedable to a second mixer via a second directional coupler, with a second oscillator, generating a second input signal having a frequency differing from the first input signal in a defined way, which is feedable to the first and second mixers, the signal coming from the mixer of the main channel and the signal coming from the mixer of the reference channel being compared, and dimensioning a terminating impedance of the reference channel as a function of the comparison so that the output signals of the main and reference channels have identical properties.

Abstract: An antenna device for receiving electromagnetic waves and a method for operating an antenna device. The antenna device is fashioned having: a bearer; at least one receive antenna device situated at an external side of the bearer, for receiving electromagnetic waves having a first polarization; at least one repolarization device situated at the external side of the bearer and fashioned to re-emit electromagnetic waves impinging on the repolarization device having the first polarization as electromagnetic waves having a second polarization; and a filter device situated at the external side of the bearer and fashioned to absorb electromagnetic waves having the second polarization.

Abstract: A radar system including a reference channel formed symmetrically in relation to a main channel, with a first oscillator, generating a first input signal, which is feedable to an antenna in the main channel, a reflected portion of the first input signal being feedable to a first mixer, the first input signal in the reference channel being feedable to a second mixer via a second directional coupler, with a second oscillator, generating a second input signal having a frequency differing from the first input signal in a defined way, which is feedable to the first and second mixers, the signal coming from the mixer of the main channel and the signal coming from the mixer of the reference channel being compared, and dimensioning a terminating impedance of the reference channel as a function of the comparison so that the output signals of the main and reference channels have identical properties.

Abstract: An antenna device for receiving electromagnetic waves and a method for operating an antenna device. The antenna device is fashioned having: a bearer; at least one receive antenna device situated at an external side of the bearer, for receiving electromagnetic waves having a first polarization; at least one repolarization device situated at the external side of the bearer and fashioned to re-emit electromagnetic waves impinging on the repolarization device having the first polarization as electromagnetic waves having a second polarization; and a filter device situated at the external side of the bearer and fashioned to absorb electromagnetic waves having the second polarization.