Sebastian Senakiewicz, 24, pleaded guilty to one felony count of falsely making a terrorist threat days before the two-day NATO summit that began May 20, the Chicago Tribune reported.
In sentencing Tuesday, Judge Nicholas Ford recommended Senakiewicz be enrolled in a prison boot camp with an eligibility for freedom if he fulfills training in as little as six months, the newspaper said.
Prosecutors said the Polish immigrant should be deported after serving his sentence.
Before the NATO summit, Senakiewicz bragged he had two bombs hidden in a hollowed-out Harry Potter book he planned to plant on a train overpass.
He is one of four men charged with terror-related offenses associated with the Black Bloc anarchist group.
In May, four other men associated with the group were arrested for allegedly plotting an attack on President Barack Obama's campaign headquarters and Chicago Mayor Rahm Emanuel's home, the Chicago Sun-Times reported.
The other suspects have all entered pleas of innocence in pre-trial hearings.