Wideband Phased Arrays - Wideband phase shift or Wideband time shift?

I am a microwave guy, and i had always thought that wideband phased arrays are implemented using wideband phase shifters. Recently, i understood from the signal processing perspective that a wideband time delay is needed rather than a wideband phase shift.

Does anybody have any thoughts?

I was pointed to this report: "The Frequency Response of Phased-Array Antennas" by Brock B.C. However, i am unable to access it. If anyone has access, kindly PM me, thanks!