Jacob R. Randall

and 3 more

We present a dynamic antenna array system for vehicle-to-everything (V2X) communications applications that is capable of steering a spatially narrow information beam to provide increased wireless security at the physical layer. The array is based on a standard 1×2 patch antenna array with 0.5λ spacing with an amplitude imbalanced feed using a Wilkinson divider and an in-series double-pole-double-throw (DPDT) RF switch. Switching the outputs of the asymmetric Wilkinson divider rapidly between the two antenna inputs induces an additive dynamic modulation towards undesired directions. This dynamic modulation corrupts the data transferred through the channel by increasing the bit error ratio (BER) towards undesired directions, but maintain zero BER at the desired direction, referred to as the information beam. Traditional phase weighting is shown to steer the information beam to an arbitrary direction. Wireless communication security is demonstrated using a 1×2 patch antenna array designed at 2.5 GHz. The physical layer modulation scheme used is 16-QAM transmitting 48 kbit bursts. The data-stream is a pseudo-random bit sequence (PRBS) transmitting at a rate 4 Mbits/s. The DPDT RF switch was driven at a comparatively slow rate of 1 kHz. The communication system was operating at a minimum SNR of 25 dB so that any bit errors are due to the phase and amplitude dynamics, and not due to low SNR. The dynamic array obtained a low BER of < 10 −3 within an information beam of 25 • at broadside, and ∼ 45 • when the array is steered to ±30 • , while a traditional static array yielded low BER at all angles (no wireless security).