A single RF channel smart antenna receiver array with digital beamforming for WLAN application

A low-noise smart antenna array with adaptive beamforming is proposed. The system employs a Spatial Multiplexing of Local Elements (SMILE) scheme to reduce N RF-channels to one, reducing the amount of costly RF hardware by a factor of N. The sampling rate must be higher than the signal bandwidth based on the Nyquist criterion to ensure proper restoration of the original signal. The multiplexing network is implemented with low-noise amplifier switches utilizing NE32485C HJFETs and a non-conventional feed network. Switching is achieved at 20 MHz allowing up to 10 Mbps reception. Beamforming and digital data demodulation is performed to validate the system.