An Active Frequency Selective Surface with a PIN Diode Switching Mechanism

This paper presents an active frequency selective surface design based on slot arrays. A novel biasing technique is described for switching the PIN diode on and off. The bandpass response can be switched between transmitting and reflecting modes. The biasing layer is printed on one layer, whereas the slot is printed in halves on both layers, separated by a substrate. The DC bias lines allow independent control of each row of the active frequency selective surface (AFSS). The resultant AFSS has a low insertion loss of 0.45 dB at 2.5 GHz and high reflectivity when the PIN diodes are switched off and on, respectively.