Minimum-noise-variance beamformer with an electromagnetic vector sensor

We study the performance of the minimum-noise-variance beamformer employing a single electromagnetic (EM) vector sensor that is capable of measuring t he complete electric and magnetic fields induced by EM signals at one point . Two types of signals are considered: One carries a single message, and th e other carries two independent messages simultaneously, The state of polar ization of the interference under consideration ranges from completely pola rized to unpolarized, We first obtain explicit expressions for the signal t o interference-plus-noise ratio (SINR) in terms of the parameters of the si gnal, interference, and noise. Then, we discuss some physical implications associated with the SINR expressions. These expressions provide a basis for effective interference suppression as well as generation of dual-message s ignals of which the two message signals have minimum interference effect on one another, We also analyze the characteristics of the main-lobe and side -lobe of the ebeampattern of an EM vector sensor and compare them with othe r types of sensor arrays.