4 by 4 ultra-wideband milimeter-wave printed log-periodic dipole array antenna

16 elements of ultra-wideband millimetre-wave printed log-periodic dipole array antenna (LPDAA) which fed by the 4-by-4 Wilkinson power distribution network is designed and fabricated for far distance chipless RFID system application. The LPDAAs are design on single side of the Taconic TLX-8 (□_r = 2.55) with 0.5 mm thickness and the feeding network is design on the same material but with 0.13 mm thickness. The antenna is designed to operate in 20-30 GHz. The total array dimension including its power distribution network is 80 × 78 × 60 mm. Radiation pattern is obtained throughout the measured bandwidth. The measured gain of the array is average at 25 dBi over the frequency range of 20-30 GHz and the cross-polarization ratio is less than -20 dB. The printable structure, low return loss, wide bandwidth and high gain of the proposed array suggest it as a suitable antenna for many applications in mm-wave range including chipless RFID systems.