Ka-band beam switchable Fresnel reflector

This paper proposed an active Fresnel reflector antenna. The antenna consists of two different dimensions of passive array cell and one active array cell. Phase shift of the active cell varies π rad by applying bias voltage into a diode. Advantage of the reflector antenna is small power consumption due to the limited number of active cells and their complement function mode. The concept achieves to save about 74 % to general active reflectarray that includes a diode for every cell. Effectiveness of the antenna concept is confirmed with a full wave simulation including equivalent circuits of the diode. The PIN diode switched the antenna beam direction 0 degree or 45 degree as intended. The gain degradation due to the active cells was only 1 - 1.7 dB in spite of power consumption saving. The next step of this study is to design the practical feeding circuit for diodes and to prepare the antenna prototype, then to measure the characteristics.