Smart Antennas Control Circuits for Automotive Communications

This paper presents two architectures allowing to perform beam steering and beam forming by controlling the relative amplitudes and phases of the signals applied on each element of a linear antenna array. The first one is based on the use of an array of coupled oscillators operating at 900 MHz. In this case, a CAD tool, which provides the frequency locking region of the coupled oscillators is presented and the application of the proposed tool to beam steering is illustrated. Experimental results of an array of 4 oscillators are then shown. The second architecture uses vector modulators to achieve the required relative amplitude and phase. In this case, noise sensitivity is first studied and simulated to prove the interest of this architecture and experimental results of a prototype including an array of four “patch” antennas controlled by the vector modulators will be presented.