Five-bit substrate guided wave true-time delay module working up to 2.4 THz with a packing density of 2.5 <inline-formula><roman>lines/cm</roman>^{<roman>2</roman>}</inline-formula> for phased array antenna applications

Abstract

A 5-bit true-time delay module is demonstrated. The combination of a 1-to-4 fiber beamsplitter and four 1-to-8 collinear guided-wave fanouts provides us with the required 32 surface-normal fanout beams with a delay step of 50 ps. The system design, device fabrication, and optimization of the fanout intensity uniformity down to Ϯ10% among 32 fanouts are addressed. The packing density of this device is 2.5 (delay lines)/cm 2 , which is the highest demonstrated thus far. A bandwidth of 2.4 THz is confirmed experimentally by employing a femtosecond laser and an ultrafast detector. © 1998 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(98)

Wireless communications sensing and security above 100 GHz

“…When injecting a broadband signal to a phase shifter, the different frequency components experience different phases, resulting in beam squinting. Instead, a true-time-delay operation, in which all the signal frequency components experience the same phase delay, may be required in place of a simple phase shifter for individual elements of an antenna array 8 . The design of active efficient high-gain antennas with suitable form factors and efficiency remains an important research challenge.…”