This paper discusses a new sensing strategy for the Dynamic Active Antenna which can estimate the contact point between an insensitive flexible beam and an object by using multiple mode of natural frequencies of the beam in contact with the object. We first prove that the contact position is uniquely determined if we can consider every mode of natural frequencies of the beam in contact with the object. We also show that the use of the fundamental and the second order natural frequencies is sufficient for uniquely determining the contact point if the beam has uniform mass and stiffness distribution. The strategy is composed of two steps. In the first step, the fundamental and the second order natural frequencies of the beam in contact with the object are evaluated by utilizing a Maximum Entropy Method. Then by using the mapping diagram from those two frequencies into the contact point, we can obtain the contact point. Experimental results are also shown to verify our idea.