Quadrifilar Helix Antenna (IMAGE) Stanford University School of Engineering Caption The bi-stable deployable quadrifilar helix antenna passively reconfigures its radiation characteristics in terms of pattern and polarization. | Image courtesy of Reconfigurable & Active Structures Lab Credit Image courtesy of Reconfigurable & Active Structures Lab Usage Restrictions Please use photo credit. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.