HALIFAX -- Ottawa says it will spend $21.7 million to buy additional antennas for the radar systems used aboard the Royal Canadian Navy's frigates.

The federal government says the procurement contract has been awarded to Saab Microwave Canada for 12 additional antenna sets, bringing the total investment to $97.5 million.

The frigates rely on the equipment for long-distance detection, and the new gear is expected to increase the detection ability of the radar by up to 180 kilometres.

HMCS St. John's is expected to be the first warship to get new antennas, with delivery expected in early 2021.

Under the contract, Saab is also required to make investments in the Canadian economy equal to the value of the contract.