Dear Endwave Stockholders: After careful consideration, the board of directors of Endwave Corporation, or Endwave, has unanimously adopted and approved an Agreement and Plan of Merger in which a wholly-owned subsidiary of GigOptix, Inc., or GigOptix, will merge with and into Endwave, leaving Endwave as a wholly-owned subsidiary of GigOptix. Endwave is sending you the accompanying proxy statement/prospectus to notify you of the special meeting of Endwave stockholders being held to vote on the adoption of the merger agreement and to ask you to vote at the special meeting in favor of the adoption of the merger agreement, as well as a proposal to enable Endwave to adjourn and postpone the special meeting. The special meeting will be held at 8:00 a.m. (local time) on June 17, 2011, at Endwave’s offices at 130 Baytech Drive, San Jose, CA 95134. GigOptix’ common stock trades on the OTC Bulletin Board under the symbol “GGOX.OB” and Endwave’s common stock trades on the Nasdaq Global Market under the symbol “ENWV.” If the merger is completed, GigOptix will issue shares of its common stock to holders of Endwave common stock, restricted stock units and options to purchase Endwave common stock with an exercise price less than the closing price as reported on the Nasdaq Global Market on the trading day immediately prior to the effective time of the merger, which we refer to as in-the-money options. The total number of shares GigOptix will issue to holders of outstanding Endwave in-the- money options is determined by a formula that is based on the closing price of Endwave and GigOptix common stock on the trading day immediately preceding the date the merger is completed. The intent of this formula is to give the holders of Endwave options GigOptix shares with a market value approximately equal to the “spread value” of such options. “Spread value” is the product of the total number of shares subject to the option and the difference between the closing price of Endwave’s common stock on the Nasdaq Global Market on the trading day prior to the effective time of the merger and the option’s per share exercise price. Holders of Endwave stock options that are not in-the-money will not be entitled to receive any shares of GigOptix common stock for those stock options. We believe that treating options in this manner compensates the optionholders for the current realizable value of their options but prevents any future dilution to the holders of Endwave and GigOptix stock that would result if such options were assumed by GigOptix. The number of GigOptix shares to be issued to holders of Endwave common stock and Endwave restricted stock units is determined according to a separate formula set forth in the merger agreement. The intent of this formula is for GigOptix to issue a total number of shares in exchange for Endwave common stock and Endwave restricted stock units equal to 42.5% of the outstanding stock of the combined company, minus 42.5% of the number derived from the formula used in calculating the number of shares of GigOptix common stock to be issued to holders of outstanding Endwave in-the-money options. The specific number of shares of GigOptix common stock to be issued in the merger, as well as the conversion ratio for Endwave shares and the value of the shares GigOptix will issue, cannot be determined until the time the merger is completed because the number of shares of GigOptix common stock and Endwave common stock, restricted stock units and in-the-money options outstanding at the time the merger is completed, and the closing prices of both Endwave’s and GigOptix’ common stock on the trading day immediately prior to the date the merger is completed, cannot be determined until such time. If the merger were completed on April 28, 2011, based on the GigOptix and Endwave common stock and Endwave options and restricted stock units outstanding as of such date and the respective closing prices of GigOptix’ and Endwave’s common stock on April 27, 2011, each outstanding share of Endwave common stock would convert into approximately 0.909 shares of GigOptix common stock, 9,115,007 shares of GigOptix common stock would be issued to the holders of Endwave common stock and restricted stock units, and 74,573 shares of GigOptix common stock would be issued to the holders of Endwave in- the-money options, for a total of 9,189,580 shares of GigOptix common stock issued in the merger. The merger cannot be completed unless Endwave stockholders vote to adopt the merger agreement. Your vote is very important, regardless of the number of shares of common stock you own, and Endwave urges you to take the time to vote by following the instructions on your proxy card regardless of whether you plan to attend the special meeting in person. The proxy statement/prospectus accompanying this letter provides you with detailed information about the proposed merger. It also contains information about Endwave, GigOptix, Inc. and related matters. You are encouraged to read this document carefully. In particular, you should read the “Risk Factors” section beginning on page 19 of this proxy statement/prospectus for a discussion of risks you should consider in evaluating the proposed merger and how it will affect you. The Endwave board of directors unanimously recommends that you vote “FOR” the adoption of the merger agreement and “FOR” the adjournment proposal. Sincerely, John Mikulsky President and Chief Executive Officer Endwave Corporation Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense. This proxy statement/prospectus is dated May 13, 2011, and is first being mailed to stockholders on or about May 18, 2011. ENDWAVE CORPORATION NOTICE OF SPECIAL MEETING OF STOCKHOLDERS TO BE HELD ON JUNE 17, 2011 To the Stockholders of Endwave Corporation: A special meeting of the stockholders of Endwave Corporation, a Delaware corporation, or Endwave, will be held on June 17, 2011, starting at 8:00 a.m., local time, at Endwave’s offices at 130 Baytech Drive, San Jose, CA 95134, for the following purposes: 1. to consider and vote upon the proposal to adopt the Agreement and Plan of Merger, dated as of February 4, 2011 (as it may be amended from time to time prior to the date hereof, the “merger agreement”), by and among GigOptix, Inc., a Delaware corporation, Aerie Acquisition Corporation, a Delaware corporation and wholly-owned subsidiary of GigOptix, Inc., and Endwave, a copy of which is attached as Annex A to the proxy statement/prospectus accompanying this notice; and 2. to consider and vote upon any proposal to adjourn the special meeting to a later date or time, if necessary or appropriate, to solicit additional proxies if there are an insufficient number of votes at the time of such adjournment to adopt the merger agreement. Endwave’s board of directors has designated the close of business on May 12, 2011 as the record date that will determine the stockholders who are entitled to receive notice of, and to vote at, the special meeting or at any adjournment or postponement of the special meeting. Only stockholders of record at the close of business on the record date are entitled to notice of, and to vote at, the special meeting and at any adjournment or postponement thereof. At a meeting duly called and held, Endwave’s board of directors has (i) unanimously determined that the merger agreement and the transactions contemplated thereby are fair to, advisable and in the best interests of Endwave’s stockholders, (ii) unanimously approved and adopted the merger agreement and the transactions contemplated thereby and (iii) unanimously resolved to recommend adoption of the merger agreement by the stockholders of Endwave. THE BOARD OF DIRECTORS OF ENDWAVE UNANIMOUSLY RECOMMENDS THAT YOU VOTE “FOR” THE MERGER PROPOSAL AND “FOR” THE ADJOURNMENT PROPOSAL. Please review the proxy statement/prospectus accompanying this notice for more complete information regarding the merger transaction, the merger agreement and the other matters to be considered at the special meeting. Your vote is important. Whether or not you plan to attend the special meeting in person, Endwave urges you to submit your proxy as promptly as possible by voting electronically as described in this proxy statement/prospectus or marking, signing and dating the enclosed proxy card and returning it in the pre-addressed postage-paid envelope provided. You may revoke your proxy at any time before it is voted at the special meeting. If you attend the special meeting and wish to vote in person, then you may revoke your proxy and vote in person. Please note, however, that if your shares are held of record by a broker, bank or other nominee and you wish to vote at the meeting, you must obtain a proxy issued in your name from that record holder. By Order of the Board of Directors of Endwave Corporation John Mikulsky President and Chief Executive Officer May 13, 2011 Important Notice Regarding the Availability of Proxy Materials for Endwave’s Special Meeting of Stockholders to Be Held on June 17, 2011: The accompanying proxy statement/prospectus is available at https://materials.proxyvote.com/29264A. TABLE OF CONTENTS Page QUESTIONS AND ANSWERS ABOUT THE MERGER ....................................... 1 SUMMARY ........................................................................... 6 The Companies ..................................................................... 6 The Merger ........................................................................ 10 Treatment of Endwave Stock Options and Restricted Stock Units ............................. 11 Recommendation of Endwave’s Board of Directors .......................................