May 31, 2026 Case Explained: Nos. 23-1585 24-1325 UNITED STATES v. HAOYANG YU APPEALS FROM THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF MASSACHUSETTS [Hon. William G. Young, U.S. District Judge] Before Montecalvo, Lipez, and Aframe Circuit Judges William W. Fick, with whom Daniel N. Marx, Amy Barsky, and Fick & Marx LLP were on brief, for appellant Karen Lisa Eisenstadt, Assistant United States Attorney, with whom Leah B. Foley, United States Attorney, was on brief, for December 11, 2025 Case: 24-1325 Document: 00118378209 Page: 1 Date Filed: 12/11/2025 Entry ID: 6772022 – 2 – MONTECALVO, Circuit Judge. Haoyang Yu worked for Analog Devices, Inc. (“ADI”), a company that designs and produces microchips. While employed there, Yu downloaded ADI’s proprietary information and held onto it after leaving the company. He soon started selling microchips that were similar to ADI’s. A grand jury indicted Yu on twenty-one counts, spanning possession of stolen trade secrets, wire fraud, illegal exports of controlled technology to Taiwan, visa fraud, and unlawful procurement of citizenship. At trial, a jury convicted Yu on just the first count: unlawful possession of a trade secret in violation of 18 U.S.C. § 1832(a)(3). Yu now appeals, challenging the sufficiency of the evidence as to particular elements of the charge. He also claims unconstitutional selective enforcement and prosecution, alleging that, because he is from China, he was investigated and prosecuted much more harshly than someone who is not ethnically Chinese would have been For the following reasons, we affirm I. Factual Background We recount the facts relevant to Yu’s sufficiency challenge in the light most favorable to the prosecution. See United States v. Díaz-Rosado, 857 F.3d 116, 117 (1st Cir. 2017) We provide a neutral summary of the facts relevant to his other claims. See id Case: 24-1325 Document: 00118378209 Page: 2 Date Filed: 12/11/2025 Entry ID: 6772022 – 3 – Because the jury ultimately convicted Yu on only one count — possession of a stolen trade secret, specifically, “[t]he design layout and GDS file for the HMC1022A microchip” — we focus on the facts relevant to that charge.1 We refer to this electronic file that Yu was accused of possessing as the “charged file.” We begin with relevant background about ADI and its work ADI creates microchips, which are devices that process and store information and help make electronic appliances work. As relevant to this case, ADI develops radio frequency and microwave amplifier microchips (also called “monolithic microwave integrated circuits” or “MMICs”) that allow electronic devices to broadcast and send signals over the air. MMICs are tiny; comparing them to the tip of a pencil, they can measure approximately one pencil tip long and two pencil tips wide. ADI designs MMICs for use in infrastructure — for example airplanes and cell phone towers — as opposed to consumer goods. ADI has customers in the cell phone, auto, aerospace, and defense industries. ADI’s MMICs have military uses, such as in satellites and radar. ADI designs the microchips and uses Win Semiconductor (“Win”), a company based in Taiwan, to manufacture them In 2014, ADI acquired another microchip company called Hittite Microwave Corporation (“Hittite”) Before the 1 A GDS file is the type of computer file used to convey a design layout Case: 24-1325 Document: 00118378209 Page: 3 Date Filed: 12/11/2025 Entry ID: 6772022 – 4 – acquisition, Hittite manufactured some of its MMIC designs at Win and some with another manufacturer. Each microchip manufacturer has its own particular set of manufacturing technologies, which makes it difficult for designers to switch manufacturers. But after the acquisition, ADI began the painstaking process of translating Hittite’s non-Win designs into designs that could be manufactured by Win Designing a MMIC is an iterative process. First, the designer creates a three-dimensional “schematic” for how the MMIC should operate, involving potentially thousands of mathematical formulas to model how various components work together. This process can take an experienced designer several weeks. Next, the designer uses a computer to run simulations to test how well the schematic works. The designer runs thousands of simulations to refine the schematic At the next stage, the designer creates the layout, which is a diagram that describes precisely how the components of the MMIC fit together and contains all the information needed to manufacture the MMIC. The designer then returns to the schematic and simulation stages and refines the design layout. The overall process, from starting the first Read →
May 31, 2026 Case Explained: Nos. 23-1585 24-1325 UNITED STATES v. HAOYANG YU APPEALS FROM THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF MASSACHUSETTS [Hon. William G. Young, U.S. District Judge] Before Montecalvo, Lipez, and Aframe Circuit Judges William W. Fick, with whom Daniel N. Marx, Amy Barsky, and Fick & Marx LLP were on brief, for appellant Karen Lisa Eisenstadt, Assistant United States Attorney, with whom Leah B. Foley, United States Attorney, was on brief, for December 11, 2025 Case: 23-1585 Document: 00118378209 Page: 1 Date Filed: 12/11/2025 Entry ID: 6772022 – 2 – MONTECALVO, Circuit Judge. Haoyang Yu worked for Analog Devices, Inc. (“ADI”), a company that designs and produces microchips. While employed there, Yu downloaded ADI’s proprietary information and held onto it after leaving the company. He soon started selling microchips that were similar to ADI’s. A grand jury indicted Yu on twenty-one counts, spanning possession of stolen trade secrets, wire fraud, illegal exports of controlled technology to Taiwan, visa fraud, and unlawful procurement of citizenship. At trial, a jury convicted Yu on just the first count: unlawful possession of a trade secret in violation of 18 U.S.C. § 1832(a)(3). Yu now appeals, challenging the sufficiency of the evidence as to particular elements of the charge. He also claims unconstitutional selective enforcement and prosecution, alleging that, because he is from China, he was investigated and prosecuted much more harshly than someone who is not ethnically Chinese would have been For the following reasons, we affirm I. Factual Background We recount the facts relevant to Yu’s sufficiency challenge in the light most favorable to the prosecution. See United States v. Díaz-Rosado, 857 F.3d 116, 117 (1st Cir. 2017) We provide a neutral summary of the facts relevant to his other claims. See id Case: 23-1585 Document: 00118378209 Page: 2 Date Filed: 12/11/2025 Entry ID: 6772022 – 3 – Because the jury ultimately convicted Yu on only one count — possession of a stolen trade secret, specifically, “[t]he design layout and GDS file for the HMC1022A microchip” — we focus on the facts relevant to that charge.1 We refer to this electronic file that Yu was accused of possessing as the “charged file.” We begin with relevant background about ADI and its work ADI creates microchips, which are devices that process and store information and help make electronic appliances work. As relevant to this case, ADI develops radio frequency and microwave amplifier microchips (also called “monolithic microwave integrated circuits” or “MMICs”) that allow electronic devices to broadcast and send signals over the air. MMICs are tiny; comparing them to the tip of a pencil, they can measure approximately one pencil tip long and two pencil tips wide. ADI designs MMICs for use in infrastructure — for example airplanes and cell phone towers — as opposed to consumer goods. ADI has customers in the cell phone, auto, aerospace, and defense industries. ADI’s MMICs have military uses, such as in satellites and radar. ADI designs the microchips and uses Win Semiconductor (“Win”), a company based in Taiwan, to manufacture them In 2014, ADI acquired another microchip company called Hittite Microwave Corporation (“Hittite”) Before the 1 A GDS file is the type of computer file used to convey a design layout Case: 23-1585 Document: 00118378209 Page: 3 Date Filed: 12/11/2025 Entry ID: 6772022 – 4 – acquisition, Hittite manufactured some of its MMIC designs at Win and some with another manufacturer. Each microchip manufacturer has its own particular set of manufacturing technologies, which makes it difficult for designers to switch manufacturers. But after the acquisition, ADI began the painstaking process of translating Hittite’s non-Win designs into designs that could be manufactured by Win Designing a MMIC is an iterative process. First, the designer creates a three-dimensional “schematic” for how the MMIC should operate, involving potentially thousands of mathematical formulas to model how various components work together. This process can take an experienced designer several weeks. Next, the designer uses a computer to run simulations to test how well the schematic works. The designer runs thousands of simulations to refine the schematic At the next stage, the designer creates the layout, which is a diagram that describes precisely how the components of the MMIC fit together and contains all the information needed to manufacture the MMIC. The designer then returns to the schematic and simulation stages and refines the design layout. The overall process, from starting the first Read →
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