I'm looking at this from the point of view of the technology, rather than the standards, as that's where I was involved. From a technology point of view, 802.11b (particularly its 1 and 2Mbps modes) was developed before 802.11a, and so is "older". I know this, because I had the design for the world's first 802.11a modem on my computer's screen, and one of the professors had earlier bought an instance of a DSSS WLAN (essentially 802.11b) to see how it performed.
Granted the early "802.11b" radios might not have been CMOS. Their frequency was limited by what was technically possible in a consumer product though. I can't remember exactly what was in that "802.11b" WLAN. The 802.11a band was definitely set by what was possible in CMOS. The CMOS radio itself might not have existed in 1995, but planning was in progress and we had a pretty good idea of what was possible.
