Dielectric lens antennas provide significant advantages for various radar-based applications. While an ellipsoidal geometry is often utilized due to its beneficial antenna characteristics and its point-like feed into the lens, its length and antenna reflections are drawbacks for some applications. In this work, we investigate the design of a Fresnel-based lens antenna to overcome these limitations. A quasioptical design is presented, highlighting its ability to reduce internal reflections of lens antennas. Additionally, the effects of the number of Fresnel steps and manufacturing tolerances are analyzed. Measurements validate the design and demonstrate the reduction of internal reflections by more than 13 dB, leading to an increased measurement range in a Tank Level Probing Radar scenario and a size and weight reduction of 41% and 34%, respectively.
