Xiaotong Lin and the problem worth changing the plan for

Xiaotong Lin started Coolstar Technology with a plan that sounded relatively contained: license the technology. Then the economics of customizing it became harder to justify. She and her partner changed direction toward making complete chips. A smaller-looking business had led to a larger undertaking. The decision meant dealing with the foundry, the device, the circuit and production. The chip would have to make sense all the way through.

That episode gives Lin’s career its particular interest. Here was an engineer with years inside established companies, choosing responsibility for more of the journey from idea to product. Coolstar, which she co-founded in 2014, became the setting for that choice. Her motto, “Dare to Dream Big,” came with a rather substantial engineering bill.

A bench at Lehigh, a career in signals

Lin’s education supplies the first part of the explanation. She earned her bachelor’s degree in electrical engineering at Shanghai Jiao Tong University in 1995, graduating from its Gifted Students Program. She later earned a master’s at Lehigh University in 1999 and a doctorate there in 2000. The subject stayed consistent while the geography changed.

Her dissertation was titled Antenna Array Processing in Wireless Communications and Radar Systems. During her doctoral studies, she worked as a research assistant in Lehigh’s Signal Processing and Communications Research Laboratory. Her research interests included space-time codes and antenna array processing. Before the executive responsibilities came a sustained education in how signals behave.

There is a useful scale change here. A university dissertation examines a bounded problem in depth. A semiconductor company has to get many bounded problems to cooperate. The early training does not explain every later decision, but it establishes how much technical work preceded the founding story. Lin arrived at entrepreneurship with a field of expertise, rather than acquiring a technical identity to suit a business idea.

After her doctorate, she joined Bell Labs at Lucent Technologies in Pennsylvania in 2000. In 2005, she moved to Broadcom in California. By the time she left Broadcom in 2014, she had worked as a senior principal scientist. Her responsibilities included ASIC architecture, with work on read-channel and Gigabit Ethernet chips.

The small decisions inside a working network

Lin contributed to IEEE 802.3az, the Energy Efficient Ethernet standard, and Automotive Broadreach industry specifications. Those names are less immediately inviting than a new consumer gadget. Their concerns sit underneath the experience of using one: communication, coordination and electrical power. A connection that works gives its internal arrangements very little publicity.

One invention makes that work more tangible. A patent granted in 2011 names Lin and Peiqing Wang as inventors on a method for detecting signals associated with Energy Efficient Ethernet’s low-power operation. The practical concern is recognizing what the device at the other end of a connection is doing.

Ethernet equipment can save power during periods of low link use by disabling some functions. But the transition needs coordination. Devices communicate their intention to enter or leave a low-power state. The invention addresses detection of the relevant request signal and a transmission mode in which the other device ceases transmitting. Mistaking one state for another can interfere with the intended operation.

That is a modest-sounding problem with a demanding requirement: the circuitry must distinguish states reliably and promptly. Saving energy still requires a conversation. Even a network taking a rest needs its arrangements in order.

Another patent, granted in 2015, names Lin, Mehmet Tazebay and Wang on clock selection for synchronous Ethernet. It describes using information about available timing sources, together with a timer, to determine whether an interface should provide timing or follow its partner. Somewhere inside a working connection, the equipment has to settle who keeps time.

These inventions give the career a texture that job titles alone cannot provide. They concern the decisions hardware makes before a user has any reason to think about it. A patent establishes a documented invention; it does not, by itself, tell us how widely that invention was used. Even with that distinction, the record shows the specificity of Lin’s engineering work.

A chip has to live in somebody else’s router

At Coolstar, the technical setting is radio frequency. The company develops front-end solutions for wireless local area networks, including Wi-Fi 6E and Wi-Fi 7 products. The front end handles functions close to the radio signal: amplifying a transmission, switching between transmitting and receiving, and amplifying a received signal with low noise.

That combination makes the company’s work easier to picture. A router contains different responsibilities packed into a common enclosure. Coolstar’s products address a particular part of that system. The company lists solutions for the 2.4, 5 and 6 GHz bands, along with products covering both 5 and 6 GHz. Its CHM57A is specified for 5.150 to 7.125 GHz.

Lin’s own inventive record reaches into this territory. She and Yi Zheng are named on a Coolstar patent granted in November 2020 for a radio-frequency power amplifier with an adjustable power supply. The design uses a configurable network of resistors and Zener diodes to establish an internal supply voltage from an applied input voltage.

The underlying issue is compatibility with the surrounding system. An amplifier has operating requirements, while the voltage available on a circuit board can vary by application. The patent describes selecting connections in the network to obtain a prescribed output voltage. It is another example of a component being designed with its neighbors in mind.

The company’s technology platform is called NovaFET. Coolstar presents it in terms of thermal behavior, power efficiency, signal quality and gain across bandwidth. Its technology description includes the 20 to 320 MHz bandwidth range required for Wi-Fi 7. These are the company’s stated engineering priorities, and they connect directly to the equipment its components are meant to serve.

There is a difference between identifying those priorities and assuming every promised advantage has been independently demonstrated. The relevant point in Lin’s story is the scope of the job she chose: developing a device platform and delivering circuit products that customers can incorporate into their own designs. The original licensing plan would have placed responsibility elsewhere along that route.

The plan needs money, and other people

Coolstar records seed funding in 2014, a Series A in 2016 and a Series B in 2021. Those dates mark separate stages of financing. They also put some distance between the founding moment and the later product work. A semiconductor business has a calendar beyond the announcement that it exists.

Lin’s role includes leading a team with expertise in analog and RF development, design, applications and operations. The range matters. A device needs people who can develop it, people who can turn it into a useful circuit and people who understand how customers will use it. An organization has to join those capabilities together.

“Leadership is more about making hard decisions at difficult times”

Xiaotong Lin

Her published advice to entrepreneurs concentrates on focus and assumptions. She warns against attempting more than available resources allow, and against defining a problem around something one simply assumes to be true. Read alongside Coolstar’s change of business model, that advice has a practical edge. Expertise helps with solving a problem; the choice of problem still deserves examination.

Her list of useful outside resources is similarly concrete: incubators, mentors, connections, introductions and specialized headhunters. It is an unromantic inventory, which is part of its appeal. A company may begin with an idea, but introductions and recruiting can determine which work becomes possible. Technical independence still involves asking other people for help.

Making room at the table

Lin also participates in the institutions around the semiconductor business. When the Global Semiconductor Alliance launched its Women’s Leadership Initiative in June 2019, she was listed among the Women’s Leadership Council participants. The council included leaders from companies such as Qualcomm, NVIDIA, AMD, Intel and TSMC, alongside semiconductor founders.

The initiative’s objectives included increasing women’s participation as founders, executives and board members, and supporting women entering the industry. Mentoring, professional networks and university connections formed part of that effort. Lin’s presence puts her entrepreneurship inside a wider professional community, with opportunities to exchange experience across companies.

In 2022, she was listed as an entrepreneurship panelist for the WLI Asia-Pacific Executive Conference. The session brought together representatives from Arm Taiwan, Baiyan Global Consulting and Micron Ventures, with Anchor Taiwan’s Elisa Chiu moderating. Entrepreneurship was being discussed alongside leadership and sustainability, as part of the same industry conversation.

On February 5, 2025, Lin presented Coolstar at GSA WLI’s Inclusive Semiconductor Entrepreneurship event at NVIDIA’s Santa Clara offices. Ten companies were represented. The event combined company introductions with presentations, networking and investor participation. Participating startups were required to have at least one woman in leadership.

It is a fitting scene in which to leave her: an engineer presenting a company to a room of other people whose decisions may affect what gets built. The responsibility has expanded since the dissertation and the individual circuit problem. There are products, colleagues and relationships to account for. Coolstar’s first plan changed. Lin took on the work that followed.