Miniaturised bandpass frequency selective surface with lumped components

A miniaturised frequency selective surface (FSS) loaded with lumped components is presented. The FSS uses inductors and capacitors to provide a bandpass response with a simulated unit cell size of lambda/115 with a - 3 dB bandwidth of 23.9%. This is the first reported use of the combination of capacitors and inductors to provide miniaturisation to this extent. Measurements are presented to validate the technique, showing an FSS resonating at 945 MHz with 21.9% bandwidth and a unit cell size of lambda/18.