What would escort Canadian Invincibles?

How would the Royal Canadian Navy evolve enough air-defence capability to escort two carriers?

Canada would need a heavier air-defence ship than its ASW escorts, most plausibly imported Type 42s or a Canadian hull built around Sea Dart.

The later Tribal-class destroyers provide a starting point, but the Canadian carrier group needs more area-air-defence weight. Charles F. Adams derivatives were an earlier possibility, yet the relevant American production programs belong mainly to the 1960s and Spruance is not an air-defence destroyer. In the 1970s, Type 42 is the active allied air-defence line Canada could join. The alternative is to take Sea Dart and design a national hull around it. Either choice changes Canadian naval development because carrier aviation cannot operate securely with ASW escorts alone. The escort requirement is a central cost of buying the carrier rather than an afterthought.