IRVINE, Calif. and BEND, Ore., Nov 2, 2005 -- Microsemi Corporation ("Microsemi") (Nasdaq:MSCC) and Advanced Power Technology, Inc. ("APT") (Nasdaq:APTI) today announced the signing of a definitive agreement for Microsemi to acquire APT. With this acquisition, Microsemi, a world leader in the design and manufacture of high performance analog solutions and high reliability semiconductor solutions, expands its portfolio of analog mixed signal offering in the RF marketplace and also its high reliability offering in the defense/aerospace and medical marketplace.

Under the terms of the agreement, each APT shareholder will receive $2.00 per share in cash and 0.435 shares of Microsemi common stock for each share of APT common stock. Based on closing prices as of November 2, 2005, the total consideration values APT at $12.20 per share, a 29% premium to APT's closing stock price today.

"APT is a recognized leader in its RF product offering for high frequency products for the analog market as well as being a technology leader with its high power switching products," said James J. Peterson, Microsemi's President and CEO. "Following several years of consolidation efforts, Microsemi is excited to move forward in this next stage of our life cycle. APT is the first step toward a focus on growing organically and through acquisition. We believe that there are significant efficiency gains to be realized on the operational level as well as the business opportunity level."

The transaction combines two strong high performance analog companies offering both differentiated RF product into niche end markets as well as high reliability product addressing a strong defense/aerospace and medical market. APT is a leading designer, manufacturer and marketer of high-performance RF and switching power semiconductors. With APT's strong focus on the high-power, high-speed segment of the power semiconductor market, APT's RF and power switches will greatly expand Microsemi's product offering within its existing channels. Additionally, APT has an advanced development effort in silicon carbide that offers significant advantages in future systems ranging from military to notebook applications.

In addition to the strategic opportunity that this acquisition provides, the combined company should have a profitable operating model that should generate significant cash. The combined entity has potential consolidation opportunities inline with previous restructuring efforts at both companies to improve efficiencies. Together, the companies should in time perform at greater than our 50% gross margin and 27% operating margins goals. Microsemi expects the transaction to be accretive to its third quarter fiscal year 2006 results.

"We are very pleased to join Microsemi's team," said Patrick Sireta, Chairman and CEO of APT. "This business combination will result in a very powerful value proposition to customers, investors and employees."

The boards of directors of both companies have unanimously approved the definitive agreement. The transaction is subject to customary regulatory approvals and an APT shareholder vote, and is expected to close at the beginning of the second quarter of Microsemi's fiscal 2006. After the transaction, Microsemi will have approximately 71 million fully diluted shares outstanding, with current Microsemi shareholders owning approximately 93% and current APT shareholders owning approximately 7% of the combined company's shares.

About the Microsemi

Microsemi Corporation, with corporate headquarters in Irvine, California, is a leading designer, manufacturer and marketer of high performance analog and mixed-signal integrated circuits and high reliability semiconductors. The company's semiconductors manage and control or regulate power, protect against transient voltage spikes and transmit, receive and amplify signals.

Microsemi's products include individual components as well as integrated circuit solutions that enhance customer designs by improving performance and reliability, battery optimization, reducing size or protecting circuits. The principal markets the company serves included implanted medical, defense/aerospace and satellite, notebook computers, monitors and LCD TVs, automotive and mobile connectivity applications. More information may be obtained by contacting the company directly or by visiting its web site at http://www.microsemi.com.

About Advanced Power Technology, Inc.

APT is a leading supplier of power semiconductors for RF, microwave, linear, and Switch mode applications. APT is headquartered in Bend, Oregon and has operations and offices in North America, France, and China. For additional information on Advanced Power Technology, visit its website at www.advancedpower.com.