intellectual property Laws assign a monopoly to designated owners

Intellectual Property Laws assign a monopoly to designated owners. However, the Sharman Antitrust Act of 1890, section 2 restraints the possession of monopoly power. How would Intellectual Property Laws don’t contradict the Sherman Antitrust Act of 1890?

Note:

You should answer the question with a minimum of 200 words.
No need for references to be included.