Tejas huh?
I wonder if that is a play toward getting a thumbs up from us Texans?
The author seems to think that AESAs are the only radars that have active electronic phase-shift beam steering which is untrue.
There are many types of phased-array antennas (from space fed, to constrained-feed/corporate fed, to AESA) that all basically do the same electronic beam switching.
The benefit of an AESA over the other more conventional PARs is the RF signal (and receiver) are basically AT the antenna element (whether patch, small aperture or other). This offers minimal power loss to the radiating element, and minimal loss to the receiver. Essentially, it is a more sensitive receiver with a combined element power that is matched for the detection requirements of the overall radar.
The problem is in getting the individual element cost down while maintaining required performance and to achieve the right MTBF.