What is the test for determining whether evidence obtained during an unlawful search is inadmissible?

"Federal constitutional standards generally govern our review of claims that evidence is inadmissible because it was obtained during an unlawful search." (People v. Willis (2002) 28 Cal.4th 22, 29.) "In reviewing a suppression ruling, 'we defer to the superior court's express and implied factual findings if they are supported by substantial evidence, [but] we exercise our independent judgment in determining the legality of a search on the facts so found.' " (People v. Lomax (2010) 49 Cal.4th 530, 563.) We will affirm the trial court's ruling if correct on any theory of applicable law. (People v. Zapien (1993) 4 Cal.4th 929, 976.)