A vacuum tube, electron tube, valve, or tube, is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.
Siemens AG is a German multinational technology conglomerate. Its operations encompass automation and digitalization in the process and manufacturing industries, intelligent infrastructure for buildings and distributed energy systems, rail transport solutions, as well as health technology and digital healthcare services. Siemens is the largest industrial manufacturing company in Europe, and holds the position of global market leader in industrial automation and industrial software.
A klystron is a specialized linear-beam vacuum tube, invented in 1937 by American electrical engineers Russell and Sigurd Varian, which is used as an amplifier for high radio frequencies, from UHF up into the microwave range. Low-power klystrons are used as oscillators in terrestrial microwave relay communications links, while high-power klystrons are used as output tubes in UHF television transmitters, satellite communication, radar transmitters, and to generate the drive power for modern particle accelerators.
Investor AB is a Swedish investment and holding company, often considered a de facto conglomerate. One of Sweden's largest companies, Investor AB serves as the investment arm of the prominent Swedish Wallenberg family; the family's companies are involved in a variety of industries, of which the primary industries are pharmaceuticals, telecommunications and industry.
Blackstone Inc. is an American alternative investment management company based in New York City. Blackstone's private equity business has been one of the largest investors in leveraged buyouts in the last three decades, while its real estate business has actively acquired commercial real estate. Blackstone is also active in credit, infrastructure, hedge funds, insurance, secondaries, and growth equity. As of June 2023, the company's total assets under management were approximately US$1 trillion, making it the largest alternative investment firm globally.
TPG Inc., previously known as Texas Pacific Group and TPG Capital, is an American private equity firm based in Fort Worth, Texas. The firm is focused on leveraged buyouts and growth capital. TPG manages investment funds in growth capital, venture capital, public equity, and debt investments. The firm invests in a range of industries including consumer/retail, media and telecommunications, industrials, technology, travel, leisure, and health care.
Nielsen Holdings plc is an American information, data and market measurement firm. Nielsen operates in over 100 countries and employs approximately 44,000 people worldwide.
Bain Capital is an American private investment firm based in Boston. It specializes in private equity, venture capital, credit, public equity, impact investing, life sciences, crypto, tech opportunities, partnership opportunities, special situations, and real estate. Bain Capital invests across a range of industry sectors and geographic regions. As of 2022, the firm managed approximately $165 billion of investor capital. The firm was founded in 1984 by partners from the consulting firm Bain & Company. The company is headquartered at 200 Clarendon Street in Boston with 22 offices in North America, Europe, Asia, and Australia.
Charles Vincent Litton Sr. (1904–1972) was an engineer and inventor from the area now known as Silicon Valley.
Eimac is a trade mark of Eimac Products, part of the Microwave Power Products Division of Communications & Power Industries. It produces power vacuum tubes for radio frequency applications such as broadcast and radar transmitters. The company name is an initialism from the names of the founders, William Eitel and Jack McCullough.
Machlett Laboratories was a Northeastern United States-based company that manufactured X-ray and high-power vacuum tubes. Machlett was a large producer of the tubes and developed accessories to be used with them as well.
Varian Associates was one of the first high-tech companies in Silicon Valley. It was founded in 1948 by Russell H. and Sigurd F. Varian, William Webster Hansen, and Edward Ginzton to sell the klystron, the first vacuum tube which could amplify electromagnetic waves at microwave frequencies, and other electromagnetic equipment. Varian Associates split into three companies in 1999: Varian Medical Systems, Varian, Inc. and Varian Semiconductor.
Welsh, Carson, Anderson & Stowe (WCAS), also referred to as Welsh Carson, is a private equity firm. WCAS was formed in 1979 and focuses on investing in two growth industries, technology and healthcare, primarily in the United States. WCAS has a current portfolio of approximately 30 companies and has organized 17 limited partnerships with total capital of over $27 billion, consisting of 13 equity partnerships and four subordinated debt partnerships. WCAS is currently investing equity funds, including WCAS XII, L.P. and WCAS XIII, L.P.
The early history of private equity relates to one of the major periods in the history of private equity and venture capital. Within the broader private equity industry, two distinct sub-industries, leveraged buyouts and venture capital experienced growth along parallel although interrelated tracks.
Francisco Partners, legally Francisco Partners Management, L.P., is an American private equity firm focused exclusively on investments in technology and technology-enabled services businesses. It was founded in August 1999 and based in San Francisco with offices in London and New York City.
Lindsay Goldberg (LGLLC) is an American private equity firm focused on leveraged buyout and growth capital investments in middle-market companies in such sectors as consumer products, commodity-based manufacturing, energy services, business services, healthcare, financial services, energy transmission and waste disposal.
Elron Electronic Industries is an Israeli technology holding company based in Tel Aviv; since 1962 the company has been involved in setting up, funding and developing over 30 companies and is considered one of the foundation stones of the high-tech industry in Israel. The company's sectors of interest include clean technology, software, semiconductors, medical technology, telecommunications, defence and aerospace. Today, the combined annual revenues of the companies established by Elron are approximately $5 billion.
TransDigm Group is a publicly traded aerospace manufacturing company headquartered in Cleveland, Ohio. TransDigm develops and manufactures engineered aerospace components. It was founded in 1993, when four industrial aerospace companies were combined by a private equity firm in a leveraged buyout. TransDigm expanded the range of aerospace components it manufactures through acquisitions over the years. It filed an initial public offering on the New York Stock Exchange in 2006.
Vista Equity Partners is an American private equity firm that invests in software, data, and technology-enabled businesses. With over $100 billion in AUM, it is one of the largest private equity firms in the world. Vista has invested in hundreds of technology companies, including Citrix, SentinelOne, and Marketo.
Stellant Systems Inc. is a manufacturer of microwave devices for ground-based, airborne and satellite communications and radar. In October 2021, Stellant systems was formed from L3Harris Technologies' Electron Devices and Narda Microwave-West divisions when both were sold to Arlington Capital Partners, a Washington D.C. based private equity firm. The company was initially formed from the former Electron Devices Division (EDD) of the Industrial Electronics Group of the Hughes Aircraft Company, and from Litton Industries' Electron Division, both of which were acquired by L-3 Communications Holdings, Inc. L-3 later merged with Harris Corporation in 2019 to form L3Harris Technologies which was followed shortly by both divisions' sale to Arlington in 2021. Stellant is known for their traveling-wave tubes (TWTs), traveling-wave tube amplifiers (TWTAs), microwave power modules (MPMs) and electronic power conditioners (EPCs) as well as xenon gas ion propulsion systems (XIPS). Since its inception, EDD has produced tens of thousands of TWTs. They are the only U.S. supplier of space-qualified TWTs and TWTAs.
