Techniques for interfacing a set of active elements with an antenna array. In one exemplary embodiment, the active elements include a plurality of signal paths, each signal path including a mixer coupled to a local oscillator (LO) signal having an adjustable phase. When the active elements are to be interfaced with an unbalanced antenna, the phase of the LO signal for each signal path coupled to the unbalanced antenna may be adjusted independently of the other signal paths. When the active elements are to be interfaced with a balanced antenna, the phases of the LO signals for the two signal paths coupled to the balanced antenna are adjusted to differ by π radians from each other. The techniques may be applied in either receiver or transmitter applications to provide a flexible interface between an antenna array and an integrated circuit (IC) without the use of baluns.