Integrated Dispersive Delay Line (Ddl) For Real Time Analog Signal Processing
The dispersive delay line (DDL) is a very useful device in the communication system for decades. It is widely utilized in the radar communication system, optical communication system, ultra-wide-bandwidth (UWB) system, etc. Even though there are a number of DDLs operating in microwave, RF, photonics regime, etc., few attempts have been reported towards the integration of this useful device. Our work focuses on the integration of the DDL with standard CMOS process. There are two major challenges in the integration of the DDL, on-chip loss and the non-idealities in DDL's performance. In this thesis, we present three major attempts to solve these challenges and all of these attempts employ the distributed amplifiers (DAs). In the DA, the artificial transmission line section is very size efficient in providing enough group delay and the gain cells are capable of gain compensation for on -chip loss. The first attempt employs the specially designed highly dispersive artificial transmission line section. The second attempt employs the multi-path approach to compensate the great loss near the cutoff frequency. The third attempt, however, employs the backward traveling gain port of the DA to realize a reconfigurable integrated transversal filter. Since most of the existing DDLs can be mapped to transversal filters with correspondent tap coefficients, the reconfigurable integrated transversal filter can be utilized to achieve multiple DDL functions. iii This thesis also includes the demonstration of the real time analog signal processing using these integrated DDLs, including the first on-chip demonstration of the temporal imager (TI), time stretching (TS) system, and real time spectrum analysis using the integrated DDL with the third attempt. Our integrated DDL has low TBP value of five and practical design considerations of the integrated TS system with small TBP remain unexplored. We derive the time resolution of a general TS system using both the principle of uncertainty and the Short Time Fourier Transform (STFT) method. This fundamental result enables a designer to understand the qualitative relationship between the TBP and the best possible resolution of the TS system. iv
Apsel, Alyssa B.
Pollock, Clifford Raymond; Afshari, Ehsan
Ph. D., Electrical Engineering
Doctor of Philosophy
dissertation or thesis