There's some treasure chests containing a Phrenic Bow, but there's only 2 respawning locations. The respawning Phrenic Bows are carried by enemies.

Does phrenic bow Respawn Botw?

Link can obtain one in the Myahm Agana Shrine. Another can be obtained from a buried treasure chest in the Deya Village Ruins. A Lizalfos lookout at an enemy camp in Rikoka Hills also wields one and respawns every Blood Moon.

Where can I find phrenic bow?

They're most commonly found in Treasure Chests in and around Lake Hylia and West Necluda. There is also a Lizalfos that uses a Phrenic Bow at the skull rock base north of Sahasra Slope in the Lanayru Wetlands. Sheikah archers, such as Impa's bodyguard Cado, utilize Phrenic Bows in Kakariko Village.