All-optical ultra-wideband tightly-coupled phased antenna array

We present an “end-to-end optical” phased-array transmitter system concept, taking maximal advantage of the benefits inherent to photonics. Specifically, an ultra-widely tunable carrier signal generator, comprising a pair of offset injection-locked lasers, illuminates an array of photodiodes mounted directly at the feed points of an array of tightly coupled, wideband, low-gain antenna elements. Both high-speed data and beam-forming are imparted onto one of the laser wavelengths by optical modulators in the feed paths to each individual element. This modulation is preserved upon downconversion at the photodiodes, which comprise nearly ideal current sources driving each element of a tightly-coupled-array antenna.