GCT Semiconductor Holding, Inc., a fabless semiconductor company, designs, manufactures, and sells communication semiconductors for industrial, business-to-business, and consumer applications in the United States, Taiwan, China, Germany, and South Korea. The company offers wireless communication technologies, such as 5G/5.75G/4.5G/4G transceivers and modems; RF and modem chipsets based on fourth-generation (4G) long term evolution (LTE) technology, including 4G LTE, 4.5G LTE Advanced, and 4.75G LTE Advanced-Pro; baseband modem solutions, RF transceivers, and system-on-chip (SoC) solutions; and product design and support, warranty development, customer support, and technical support services. It also develops and sells cellular Internet of Things (IoT) chipsets for low-speed mobile networks, such as eMTC/NB-IOT/Sigfox, and other network protocols; and 5G NR chipsets and other 5G NR solutions. The company's products and solutions are used in portable wireless routers, indoor and outdoor fixed wireless routers, industrial machine-to-machine applications, smartphones, fixed wireless subscriber terminals, various communication modules and devices, and industrial products. It sells its products directly or indirectly through distributors to wireless operators, original equipment manufacturers (OEMs), and original design manufacturers (ODMs) in Taiwan, China, Korea, Japan, Europe, North America, and South America. GCT Semiconductor Holding, Inc. was founded in 1998 and is headquartered in San Jose, California.