Provided herein are systems, devices, assemblies, and methods for localization of a tag in a tissue of a patient. For example, provided herein are systems, devices, and methods employing an implantable tag that emits sidebands at defined frequencies upon activation by a magnetic field generated by a remote activating device, and a plurality of witness stations configured to detect such sidebands. Also provided herein are herein are systems, devices, and methods employing a detection component that is attached to or integrated with a surgical device.