El Segundo-based International Rectifier said Friday afternoon that it has received an unsolicited proposal from Vishay Intertechnology to acquire the firm. The deal is worth $21.22 per share, or approximately $1.6 billion. According to International Rectifier, the firm's board of directors will evaluate the proposal consultation with its financial and legal advisers. International Rectifier is a manufacturer of analog, digital, and mixed signal semiconductors.