Support Technology and Research for Our Nation's Growth and Economic Resilience Patents Act of 2019 or the STRONGER Patents Act of 2019 This bill makes several patent-related changes, including with respect to how the U.S. Patent and Trademark Office (USPTO) conducts administrative patent validity reviews. When deciding inter partes reviews (IPRs) and post-grant reviews (PGRs), the USPTO's Patent Trial and Appeal Board (PTAB) shall give patent claim terms their ordinary and customary meanings as understood by a person of ordinary skill in the relevant art (the same standard used in court). If a court has already construed a patent claim, the USPTO shall consider that construction. The bill makes various changes relating to such proceedings, such as by (1) raising the burden of proof to invalidate a patent claim; (2) establishing that a challenged patent claim is presumed valid; (3) imposing standing requirements as to who may file an IPR or PGR, where none currently exist except for some timing requirements; (4) restricting when multiple challenges may be filed against the same patent; and (5) limiting IPRs and PGRs when a court or the International Trade Commission has ruled on the obviousness or novelty of the same patent claims. This bill also (1) makes it easier to get an injunction after a court finding of the infringement of a valid patent, by a presumption that further infringement would cause irreparable injury and the remedies available at law are inadequate; (2) authorizes the USPTO to keep and spend the fees that it collects; and (3) makes bad faith patent demand letters an unfair or deceptive act in violation of the Federal Trade Commission Act.