A differential antenna and associated control system applied to a digital television (TV). The control system includes a differential antenna receiving a broadcasting signal and generating a differential radio frequency (RF) signal including a positive signal and a negative signal; a control unit generating a selecting signal according to a selected channel; a switch circuit including a switch control circuit and a plurality of matching circuits. Each of the matching circuits optimizes part of the digital TV bandwidth, and the switch control circuit receives the selecting signal to control that an optimized positive signal is generated to the control unit after the positive signal passes through a first matching circuit of the matching circuits, and an optimized negative signal is generated to the control unit after the negative signal passes through a second matching circuit of the matching circuits. The first matching circuit and the second matching circuit optimize the same frequency band, and a differential optimizing signal includes the optimized positive signal and the optimized negative signal. Thus, the control unit generates a selected channel signal accordingly.