Sehr schön. Danke Deutschland!
Here is another one. Huge thing this time, designed for 433MHz, polarization RHCP. For dimensions etc. see design description below.
Here is another quadrifilar helix antenna design, this time for ADSB (aircraft mode-S transponder) reception at 1090 MHz. Unlike other antenna types this antenna has a spherical coverage with 120° 3dB beamwidth and estimated peak gain of 4.6dBi at 1090MHz.