Additively Manufactured Endfire Bifilar Helix Antenna for E-Band

In this work, an additively manufactured endfire bifilar helix antenna with a center frequency of fc = 66 GHz employing a novel transition from bifilar helix to E-band waveguide is presented. This novel transition enables a higher bandwidth of the antenna and also tuning of the antenna matching. Mea- surements suggest a -20 dB-bandwidth of B20dB ≈ 5.2 GHz and -15 dB-bandwidth of B15dB = 16 GHz respectively. An axial ratio below AR<3.15dB is achieved over the entire E-Band and even AR < 2 dB within B20dB in main lobe direction. The realized linear polarization gain ranges at Glp 11 dBi with a circular polarization gain of Gcp 12 to 13dBi was measured. Hence, measurements suggest general feasibility of the proposed bifilar helix antenna for mmWave applications due to the small form factor of the antenna and the circular polarization. Those applications in future could be satellite systems or future 6G infrastructures.