Reconfigurable Hilbert antennas using high speed pin codes

A low-profile antenna based on a Hilbert space filling curve of order n=2 was designed, simulated, fabricated and measured to show the range of reconfigurability options of this type of space-filling curve conformal antenna. PIN diodes were used for reconfigurability and the antenna exhibited two resonant frequency bands. The upper band showed a 16% VSWR <2 bandwidth with a center frequency of 875 MHz for the four switch states. The lower band in the range of 250 to 450 MHz showed two narrower resonance bands of approximately 20% each. The simulated return loss results showed excellent agreement with measured return loss results on the antenna, validating the concept of reconfigurable Hilbert antennas as a way to widen the bandwidth of these antennas.