Simultaneous transmit and receive requires extremely high isolation between the transmitters and receivers. By designing an antenna array to have high isolation between elements, it is possible to enable simultaneous transmit and receive at the same frequency. In this paper, a technique to achieve over 70 dB of inter-element isolation using tunable resonators placed between antenna elements is demonstrated. The effects of these tunable resonant baffles on the active scan impedance and array patterns is then discussed.