PHASED ARRAY SMART ANTENNA WITH CIRCULAR POLARIZATION AND ELECTRICAL DOWNTILT USING MULTIPLE PHASES OF LOCAL OSCILLATOR CLOCK

摘要

A smart antenna system for achieving circularly polarized and electrically down tilted phased array signals is provided. The baseband transmitter (302) transmits a baseband signal. The first voltage controlled oscillator (a) modulates the baseband signal to a plurality of phase shifted intermediate frequency signals, and the second voltage controlled oscillator (b) modulates the plurality of phase shifted intermediate frequency signals to a plurality of phase shifted radio frequency signals. The plurality of power amplifiers (308A-N) amplify the plurality of phase shifted radio frequency signals. The plurality of antennas (102A-N) radiate the plurality of phase shifted radio frequency signals for generating the phased array signals. The phased array signals achieve (i) tilting of an antenna radiation plane of the plurality of antennas (102A-N) from an initial position (104) to a tilted position (106) and (ii) transmitting the plurality of phase shifted radio frequency signals in a circular polarization.