Compact antenna for digital beamforming with software defined radios

An adaptive radio system combining compact switchless reconfigurable antenna with Software Defined Radio is proposed. The system allows control of the direction of the transmitted signal solely by adjusting the baseband I and Q components of the modulated signal, while maintaining small antenna size through the use of compact multiport antenna. The system is demonstrated in a line-of-sight configuration with QPSK modulation. Experimental results demonstrate good received power and low error vector magnitude of the demodulated signals.