Verification of TTD Based Time Control Device for SI Cancellation in the L-Band

This study experimentally validated the performance of a true-time delay (TTD)-based time control device developed to ensure the high efficiency of a self-interference (SI) cancellation system operating in the L-band (1~2 GHz) frequency range of global navigation satellite systems (GNSS). The fabricated time-delay control module utilizes TTD elements to implement precise time-delay control functionality with picosecond resolution. The performance of the module, specifically its time delay control capability, was thoroughly evaluated in the L-band. The experimental results successfully verified the picosecond-level time delay accuracy, which is essential for achieving a high SI signal cancellation rate. Furthermore, the effectiveness of the module in achieving successful self-interference cancellation with a high signal cancellation rate exceeding 99.99 %, was empirically demonstrated.