SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

[Rule 13d-101]

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a)

AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a)

(Amendment No. 10)*

Clearwire Corporation

(Name of Issuer)

Class A Common Stock

(Title of Class of Securities)

18538Q105

(CUSIP Number)

David K. Schumacher

General Counsel

Crest Financial Limited

JP Morgan Chase Tower

600 Travis, Suite 6800

Houston, TX 77002

Tel: (713) 222 6900

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

Copies to:

Stephen M. Gill

Kai Haakon E. Liekefett

Vinson & Elkins LLP

First City Tower

1001 Fannin Street, Suite 2500

Houston, TX 77002

Tel: (713) 758 2222

May 6, 2013

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.  ¨

Note. Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (the “Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

(Continued on following pages)

This Amendment No. 10 (this “Amendment”) amends and supplements the Statement on Schedule 13D (the “Schedule 13D”) of Crest Financial Limited (“CFL”), Crest Investment Company (“CIC”), the Jamal and Rania Daniel Revocable Trust (the “Jamal and Rania Daniel Trust”), Mr. Jamal Daniel, Mrs. Rania Daniel, DTN LNG, LLC (“DTN LNG”), DTN Investments, LLC (“DTN Investments”), the Daria Daniel 2003 Trust (the “Daria Daniel Trust”), the Thalia Daniel 2003 Trust (the “Thalia Daniel Trust”), the Naia Daniel 2003 Trust (the “Naia Daniel Trust”), Mr. John M. Howland, Mr. Eric E. Stoerr, the Halim Daniel 2012 Trust (the “Halim Daniel Trust”), Mr. Michael Wheaton, solely in his capacity as trustee of the Halim Daniel Trust, Mr. Halim Daniel, Uniteg Holding SA (“Uniteg”) and Crest Switzerland, LLC (“Crest Switzerland” and, together with CFL, CIC, the Jamal and Rania Daniel Trust, Mr. Jamal Daniel, Mrs. Daniel, DTN LNG, DTN Investments, the Daria Daniel Trust, the Thalia Daniel Trust, the Naia Daniel Trust, Mr. Howland, Mr. Stoerr, the Halim Daniel Trust, Mr. Wheaton, solely in his capacity as trustee of the Halim Daniel Trust, Mr. Halim Daniel, Uniteg and Crest Switzerland, the “Reporting Persons”) that was filed in respect of Clearwire Corporation (the “Issuer”) on June 1, 2012 and amended by Amendment No. 1 filed on November 7, 2012 (“Amendment No. 1”), Amendment No. 2 filed on December 18, 2012 (“Amendment No. 2”), Amendment No. 3 filed on March 13, 2013 (“Amendment No. 3”), Amendment No. 4 filed on March 20, 2013 (“Amendment No. 4”), Amendment No. 5 filed on April 4, 2013 (“Amendment No. 5”), Amendment No. 6 filed on April 9, 2013 (“Amendment No. 6”), Amendment No. 7 filed on April 11, 2013 (“Amendment No. 7”), Amendment No. 8 filed on April 23, 2013 (“Amendment No. 8”) and Amendment No. 9 filed on April 25, 2013.

Item 4 of the Schedule 13D is hereby amended and supplemented by adding the following paragraphs after the first paragraph thereof:

On May 3, 2013, CFL and CIC (collectively, the “Participants”) filed with the Securities and Exchange Commission (the “SEC”) a definitive proxy statement and accompanying proxy card relating to Participants’ intention to solicit proxies from the stockholders of the Issuer in connection with a special meeting of such stockholders to be held to vote upon the proposed transaction between the Issuer and Sprint-Nextel Corporation. On May 6, 2013, CFL issued a press release relating to the filing of the definitive proxy statement, a copy of which is attached hereto as Exhibit 2 and is incorporated herein by reference. The definitive proxy statement, which includes a cover letter (the “Letter to Stockholders”), and accompanying proxy card were mailed to the stockholders of the Issuer on or about May 6, 2013. A copy of the Letter to Stockholders is attached hereto as Exhibit 3 and is incorporated herein by reference.

Item 4 of the Schedule 13D is hereby amended and supplemented by replacing the thirteenth paragraph thereof (counting the above paragraph) with the following paragraph:

The definitive proxy statement was mailed to the stockholders of the Issuer on or about May 6, 2013. SECURITYHOLDERS OF THE ISSUER ARE URGED TO READ THE DEFINITIVE PROXY STATEMENT, WHICH IS AVAILABLE NOW, AND THE PARTICIPANTS’ OTHER PROXY MATERIALS FILED WITH THE SEC WHEN THEY BECOME AVAILABLE, BECAUSE THEY CONTAIN IMPORTANT INFORMATION, INCLUDING ADDITIONAL INFORMATION RELATED TO THE PARTICIPANTS, THE ISSUER AND THE PROPOSED SPRINT MERGER. The definitive proxy statement and all other proxy materials filed with the SEC are available at no charge on the SEC’s website at http://www.sec.gov. In addition, the definitive proxy statement is also available at no charge on the website of the Participants’ proxy solicitor at http://www.dfking.com/clwr.

Item 6 of the Schedule 13D is hereby amended and restated in its entirety as follows:

Other than Asset Purchase Agreement as described in Item 3 hereof (which has been fully performed by the parties thereto in 2004), the Joint Filing Agreement attached to Amendment hereto as Exhibit 1, the Press Release attached hereto as Exhibit 2, the Letter to Stockholders attached hereto as Exhibit 3, the Power of Attorney for the Daria Daniel Trust attached hereto as Exhibit 4, the Power of Attorney for the Thalia Daniel Trust attached hereto as Exhibit 5, the Power of Attorney for the Naia Daniel Trust attached hereto as Exhibit 6, the Power of Attorney for John M. Howland attached hereto as Exhibit 7, the Press Release attached to Amendment No. 9 as Exhibit 2, the Power of Attorney for the Jamal and Rania Daniel Trust attached to Amendment No. 9 as Exhibit 3, the Power of Attorney for Jamal Daniel attached to Amendment No. 9 as Exhibit 4, the Power of Attorney for Rania Daniel attached to Amendment No. 9 as Exhibit 5, the Power of Attorney for Eric E. Stoerr attached to Amendment No. 9 as Exhibit 6, the Power of Attorney for the Halim Daniel Trust attached to Amendment No. 9 as Exhibit 7, the Power of Attorney for Halim Daniel attached to Amendment No. 9 as Exhibit 8, the Power of Attorney for Michael Wheaton attached to Amendment No. 9 as Exhibit 9, the Power of Attorney for Uniteg attached to Amendment No. 9 as Exhibit 10, the Board Letter attached to Amendment No. 8 as Exhibit 2, the April 23 Press Release attached to Amendment No. 8 as Exhibit 3, the April 22 Press Release attached to Amendment No. 8 as Exhibit 4, the FCC Letter attached to Amendment No. 8 as Exhibit 5, the Press Release attached to Amendment No. 7 as Exhibit 2, the Press Release attached to Amendment No. 6 as Exhibit 2, the FCC Letter attached to Amendment No. 6 as Exhibit 3, the Letter to the Board attached to Amendment No. 5 as Exhibit 2, the April 3 Press Release attached to Amendment No. 5 as Exhibit 3, the Demand Letter attached to Amendment No. 4 as Exhibit 2, the March 20 Press Release attached to Amendment No. 4 as Exhibit 3, the March 12 Press Release attached to Amendment No. 3 as Exhibit 2, the FCC Letter attached to Amendment No. 3 as Exhibit 3, the Press Release attached to Amendment No. 2 as Exhibit 2, the Stockholder Letter attached to Amendment No. 1 as Exhibit 2 and the Press Release attached to Amendment No. 1 as Exhibit 3, neither the Reporting Persons nor, to the best of the Reporting Persons’ knowledge, any person named on Schedule A hereto, has any contracts, arrangements, understandings or relationships (legal or otherwise) among the persons named in Item 2 and between such persons and any person with respect to any securities of the Issuer, including but not limited to, transfer or voting of any of the securities, finder’s fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits, division of profits or loss, or the giving or withholding of proxies.

The following documents are filed as exhibits:

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: May 7, 2013

EXHIBIT INDEX

Exhibit 1

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a statement on Schedule 13D (including amendments thereto) with respect to the Class A Common Stock of Clearwire Corporation and further agree that this Joint Filing Agreement be included as an Exhibit to such joint filings. In evidence thereof, the undersigned, being duly authorized, have executed this Joint Filing Agreement this 7^th day of May, 2013.

Exhibit 2

FOR IMMEDIATE RELEASE:

CONTACT: Jeffrey Birnbaum, (202) 661-6367, JBirnbaum@BGRPR.com

Crest Financial Names John Quinn to Lead Trial, Mails Proxies to Block Sprint-Clearwire Merger

Urges Holders to Vote AGAINST the Proposed Merger by Voting the GOLD Proxy Card

HOUSTON, May 6, 2013—Crest Financial Limited, the largest minority stockholder of Clearwire Corporation (NASDAQ: CLWR) with an ownership of 8.25% of the Class A common stock of Clearwire, today formally began its campaign to persuade Clearwire stockholders to reject the proposed merger with Sprint Nextel Corporation by mailing its proxy statement to the Clearwire stockholders. The proxy statement was cleared by the Securities and Exchange Commission last Friday, Crest said.

Crest also announced that an experienced team of trial lawyers from Quinn Emanuel Urquhart & Sullivan LLP, the largest U.S. law firm devoted solely to business litigation, will prosecute Crest’s claims against Sprint and Clearwire in Delaware’s Chancery Court. John B. Quinn, founder and managing partner of Quinn Emanuel, will personally lead the trial team. Quinn Emanuel litigates many of the biggest and most noteworthy business cases in the U.S., with a 90 percent winning record.

“As the controlling stockholders of Clearwire, Sprint owes fiduciary duties—duties of loyalty and trust—which require it to protect the interests of the company’s minority stockholders,” John Quinn said. “But instead of acting consistent with those duties, Sprint is thumbing its nose at the other stockholders and seeking to force a sale of Clearwire at a grossly inadequate price. Clearwire directors are doing Sprint’s bidding.”

Quinn, the lead trial lawyer for Crest, added: “We expect that litigation will result in a very substantial appraisal award or damage remedy to redress the breaches of fiduciary duty by both Sprint and the Clearwire directors.”

Crest opposes the Sprint-Clearwire merger because it believes that the Sprint offer of $2.97 in cash per Clearwire share is grossly inadequate, that the merger was structured in a way that unfairly disadvantages minority stockholders, and that Clearwire would be better off if it remained a stand-alone company.

“We are optimistic that the Clearwire stockholders will agree with us that the Sprint offer is unfair and block the Sprint-Clearwire merger,” said David K. Schumacher, general counsel of Crest. “Just last Friday, four other large minority stockholders owning 18.2% of Clearwire’s Class A common stock announced their agreement to oppose the Sprint-Clearwire merger. The immense value of the wireless spectrum owned by Clearwire should benefit all Clearwire stockholders and should not be handed over on the cheap to Sprint, its controller.”

Schumacher added, “We will pursue all litigation avenues and all available remedies.”

Crest has filed a lawsuit in Delaware against Sprint, Clearwire, and the directors of Clearwire because Crest believes that the defendants breached their fiduciary duties by scheming to extract value from Clearwire at the expense of minority stockholders. Other stockholders, including Aurelius Capital Management, have also filed suit. Crest has also petitioned the Federal Communications Commission to stop the proposed SoftBank-Sprint and Sprint-Clearwire mergers because they would treat minority stockholders of Clearwire unfairly and the mergers would not be in the public interest.

“The battle for Clearwire has just begun,” Crest wrote to stockholders in its letter transmitting its proxy materials. “Clearwire’s choice is not between doing nothing and accepting a grossly inadequate Sprint deal. Rather, Clearwire’s own management has presented the most promising path to maximizing stockholder value—the MCC business plan, in which Clearwire would provide service to multiple wholesale customers in addition to Sprint. We believe that the necessary financing to enable Clearwire to pursue the MCC business plan is readily available.”

“Everyone involved in these interlocking proposals and transactions—SoftBank, Sprint, DISH, and other potential bidders—recognizes that the real prize is Clearwire and its spectrum assets. And yet the Clearwire Board of Directors has managed to negotiate a Merger Agreement that transfers all value and leverage to Sprint instead of preserving them for all Clearwire stockholders,” Crest’s letter states. “Only a vote ‘AGAINST’ the Sprint-Clearwire Merger will send a firm message to the Clearwire Board of Directors and Sprint that they owe fiduciary duties to all Clearwire stockholders—not just to Sprint.”

D.F. King & Co, Inc. has been retained by Crest to assist it in the solicitation of proxies in opposition to the merger. If stockholder have any questions or need assistance in voting the GOLD proxy card, please call D.F. King & Co. at (800) 949-2583. The proxy statement and cover letter can be found at http://www.dfking.com/clwr.

About Crest Financial Limited

Crest Financial Limited (“Crest”) is a limited partnership under the laws of the State of Texas. Its principal business is investing in securities.

Important Legal Information

In connection with the proposed merger of Clearwire with Sprint Nextel Corporation (the “Proposed Sprint Merger”), Crest and other persons (the “Participants”) have filed a definitive proxy statement with the U.S. Securities and Exchange Commission (“SEC”). The definitive proxy statement will be mailed to the stockholders of Clearwire on or about May 6, 2013. SECURITYHOLDERS OF CLEARWIRE ARE URGED TO READ THE DEFINITIVE PROXY STATEMENT, WHICH IS AVAILABLE NOW, AND THE PARTICIPANTS’ OTHER PROXY MATERIALS FILED WITH THE SEC WHEN THEY BECOME AVAILABLE, BECAUSE THEY CONTAIN IMPORTANT INFORMATION, INCLUDING ADDITIONAL INFORMATION RELATED TO THE PARTICIPANTS, CLEARWIRE AND THE PROPOSED SPRINT MERGER. The definitive proxy statement and all other proxy materials filed with the SEC are available at no charge on the SEC’s website at http://www.sec.gov. In addition, the definitive proxy statement is also available at no charge on the website of the Participants’ proxy solicitor at http://www.dfking.com/clwr.

Forward-looking Statements

Certain statements contained herein are forward-looking statements including, but not limited to, statements that are predications of or indicate future events, trends, plans or objectives. Undue reliance should not be placed on such statements because, by their nature, they are subject to known and unknown risks and uncertainties. Forward-looking statements are not guarantees of future activities and are subject to many risks and uncertainties. Due to such risks and uncertainties, actual events may differ materially from those reflected or contemplated in such forward-looking statements. Forward-looking statements can be identified by the use of the future tense or other forward-looking words such as “believe,” “expect,” “anticipate,” “intend,” “plan,” “should,” “may,” “will,” believes,” “continue,” “strategy,” “position” or the negative of those terms or other variations of them or by comparable terminology.

Exhibit 3

CREST FINANCIAL LIMITED

JPMorgan Chase Tower

600 Travis, Suite 6800

Houston, Texas 77002

May 6, 2013

Dear Fellow Clearwire Stockholders:

Crest Financial Limited (“Crest”), together with its affiliates and other related persons, owns approximately 8.25% of the outstanding Class A common stock of Clearwire Corporation (“Clearwire” or the “Company”) and is the largest independent stockholder of Clearwire.

We have been long-time investors in Clearwire. Our investment in Clearwire dates back to June 2004 when one of our affiliates sold spectrum assets to Clearwire in exchange for shares in the Company, of which Crest received approximately 1.4 million shares. Our belief in the potential of Clearwire is demonstrated by the substantial investment we have made in the Company.

Over the past several months a broad range of fellow Clearwire stockholders have spoken out against the proposed merger (the “Sprint-Clearwire Merger”) of Clearwire with Sprint Nextel Corporation (“Sprint”). Just last Friday, a group of stockholders with approximately 18.2% of the outstanding Class A common stock of Clearwire announced their agreement to oppose the Sprint-Clearwire Merger. Unlike the Clearwire Board of Directors, we have listened.

Today we are distributing definitive proxy materials in opposition to the Sprint-Clearwire Merger. Crest opposes the Sprint-Clearwire Merger because Crest believes that it would be better for Clearwire to remain a stand-alone company and pursue its long-stated business plan to exploit its valuable spectrum assets. These are our reasons:

The Merger Consideration is Grossly Inadequate

We believe that the merger consideration of $2.97 in cash per share being offered to Clearwire stockholders in the Sprint-Clearwire Merger significantly undervalues Clearwire and does not compensate fairly the stockholders:

There are Too Many Uncertainties

Even if the merger consideration of $2.97 in cash per share were not grossly inadequate, there are too many uncertainties for Clearwire’s stockholders to vote on the Sprint-Clearwire Merger on an informed basis:

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In light of these and other related questions, we wonder how the Clearwire Board of Directors could press ahead with the stockholder vote on the Sprint-Clearwire Merger.

There is an Alternative Path

Clearwire’s choice is not between doing nothing and accepting a grossly inadequate Sprint deal. Rather, Clearwire’s own management has presented the most promising path to maximizing stockholder value—the MCC business plan, in which Clearwire would provide service to multiple wholesale customers in addition to Sprint. We believe that the necessary financing to enable Clearwire to pursue the MCC business plan is readily available:

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We Believe the Clearwire Board Breached its Fiduciary Duties

Crest, Aurelius Capital Management, and other stockholders of Clearwire have filed lawsuits in the Delaware Court of Chancery, alleging that the Clearwire Board of Directors has been unfairly influenced by Sprint and that each of the Clearwire directors and Sprint has breached its fiduciary duties by entering into an unfair and coercive transaction that is harmful to the minority stockholders. These lawsuits are still pending, and during a January 10, 2013 hearing Chancellor Leo Strine, the presiding judge in our case, stated: “I think there are colorable claims here.” We have engaged noted trial lawyer John Quinn of the Quinn Emanuel Urquhart & Sullivan law firm to lead the effort to prosecute the trial for money damages and injunctive relief, or potentially to pursue a separate claim for appraisal. Crest intends to aggressively pursue its rights as a minority stockholder.

Among the reasons why we believe the Clearwire Board of Directors has breached its fiduciary duties are:

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In our opinion, the foregoing demonstrates that Clearwire’s corporate governance must improve significantly. Only a vote “AGAINST” the Sprint-Clearwire Merger will send a firm message to the Clearwire Board of Directors and Sprint that they owe fiduciary duties to all Clearwire stockholders—not just to Sprint.

*        *        *

Our activism on behalf of non-Sprint stockholders stems from a simple observation. Everyone involved in these interlocking proposals and transactions—SoftBank, Sprint, DISH, and other potential bidders—recognizes that the real prize is Clearwire and its spectrum assets. And yet the Clearwire Board of Directors has managed to negotiate a Merger Agreement that transfers all value and leverage to Sprint instead of preserving them for all Clearwire stockholders.

We believe that there are alternative paths available to Clearwire other than the Sprint-Clearwire Merger. Therefore, for all of the foregoing reasons, we urge you to vote “AGAINST” the Sprint-Clearwire Merger by signing and returning the enclosed GOLD proxy card.

Crest urges all stockholders NOT to sign or return any WHITE proxy card sent to you by the Company.

If you have already returned the WHITE proxy card, you can effectively revoke it by voting the GOLD proxy card. Only your latest-dated proxy card will be counted.

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If you have any questions or need assistance in voting the GOLD proxy card, please contact our proxy solicitor, D.F. King & Co., Inc. at 1-800-949-2583 (toll-free).

*************************************************************************************

About Crest Financial Limited

Crest is a limited partnership under the laws of the State of Texas. Its principal business is investing in securities.

Important Legal Information

In connection with the Sprint-Clearwire Merger, Crest and other persons (the “Participants”) have filed a definitive proxy statement with the U.S. Securities and Exchange Commission (“SEC”). The definitive proxy statement has been mailed to the stockholders of Clearwire. SECURITYHOLDERS OF CLEARWIRE ARE URGED TO READ THE DEFINITIVE PROXY STATEMENT AND ALL OTHER PROXY MATERIALS FILED WITH THE SEC, BECAUSE THEY CONTAIN IMPORTANT INFORMATION, INCLUDING ADDITIONAL INFORMATION RELATED TO THE PARTICIPANTS, CLEARWIRE, AND THE SPRINT-CLEARWIRE MERGER. The definitive proxy statement and all other proxy materials filed with the SEC are available at no charge on the SEC’s website at http://www.sec.gov. In addition, the definitive proxy statement is also available at no charge on the website of the Participants’ proxy solicitor at http://www.dfking.com/clwr.

Forward-looking Statements

Certain statements contained herein are forward-looking statements including, but not limited to, statements that are predications of or indicate future events, trends, plans, or objectives. Undue reliance should not be placed on such statements because, by their nature, they are subject to known and unknown risks and uncertainties. Forward-looking statements are not guarantees of future activities and are subject to many risks and uncertainties. Due to such risks and uncertainties, actual events may differ materially from those reflected or contemplated in such forward-looking statements. Forward-looking statements can be identified by the use of the future tense or other forward-looking words such as “believe,” “expect,” “anticipate,” “intend,” “plan,” “should,” “may,” “will,” believes,” “continue,” “strategy,” “position,” or the negative of those terms or other variations of them or by comparable terminology.

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Exhibit 4

POWER OF ATTORNEY

FOR EXECUTING SCHEDULE 13D AND SCHEDULE 13G

The undersigned hereby constitutes and appoints each of Pamela E. Powers and David K. Schumacher, with full power of substitution, as an undersigned’s true and lawful attorney-in-fact to:

The undersigned hereby grants to each attorney-in-fact full power and authority to do and perform all and every act requisite, necessary or proper to be done in the exercise of any of the rights and powers herein granted, as fully to all intents and purposes as the undersigned might or could do if personally present, with full power of substitution or revocation, hereby ratifying and confirming all that each attorney-in-fact shall lawfully do or cause to be done by virtue of this Power of Attorney and the rights and powers granted herein. The undersigned acknowledges that none of the attorneys-in-fact, in serving in such capacity at the request of the undersigned, is assuming any of the undersigned’s responsibilities to comply with Sections 13(d) or 13(g) of the Exchange Act.

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The undersigned agrees that each attorney-in-fact may rely entirely on information furnished orally or in writing by or at the direction of the undersigned to the attorney-in-fact. The undersigned also agrees to indemnify and hold harmless each attorney-in-fact against any losses, claims, damages or liabilities (or actions in these respects) that arise out of or are based upon any untrue statements or omissions of necessary facts in the information provided by or at the direction of the undersigned, or upon the lack of timeliness in the delivery of information by or at the direction of the undersigned, to the attorneys-in fact for purposes of executing, acknowledging, delivering or filing a Schedule 13D or Schedule 13G (including amendments thereto) and agrees to reimburse each attorney-in-fact on demand for any legal or other expenses reasonably incurred in connection with investigating or defending against any such loss, claim, damage, liability or action.

This Power of Attorney shall remain in full force and effect until the undersigned is no longer required to file a Schedule 13D or Schedule 13G (including amendments thereto) with respect to the undersigned’s holdings of and transactions in securities issued by Clearwire Corporation, unless earlier revoked by the undersigned in a signed writing delivered to the attorney-in-fact. This Power of Attorney does not revoke any other power of attorney that the undersigned has previously granted.

(Signature Page Follows)

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IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of the date written below.

Exhibit 5

POWER OF ATTORNEY

FOR EXECUTING SCHEDULE 13D AND SCHEDULE 13G

The undersigned hereby constitutes and appoints each of Pamela E. Powers and David K. Schumacher, with full power of substitution, as an undersigned’s true and lawful attorney-in-fact to:

The undersigned hereby grants to each attorney-in-fact full power and authority to do and perform all and every act requisite, necessary or proper to be done in the exercise of any of the rights and powers herein granted, as fully to all intents and purposes as the undersigned might or could do if personally present, with full power of substitution or revocation, hereby ratifying and confirming all that each attorney-in-fact shall lawfully do or cause to be done by virtue of this Power of Attorney and the rights and powers granted herein. The undersigned acknowledges that none of the attorneys-in-fact, in serving in such capacity at the request of the undersigned, is assuming any of the undersigned’s responsibilities to comply with Sections 13(d) or 13(g) of the Exchange Act.

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The undersigned agrees that each attorney-in-fact may rely entirely on information furnished orally or in writing by or at the direction of the undersigned to the attorney-in-fact. The undersigned also agrees to indemnify and hold harmless each attorney-in-fact against any losses, claims, damages or liabilities (or actions in these respects) that arise out of or are based upon any untrue statements or omissions of necessary facts in the information provided by or at the direction of the undersigned, or upon the lack of timeliness in the delivery of information by or at the direction of the undersigned, to the attorneys-in fact for purposes of executing, acknowledging, delivering or filing a Schedule 13D or Schedule 13G (including amendments thereto) and agrees to reimburse each attorney-in-fact on demand for any legal or other expenses reasonably incurred in connection with investigating or defending against any such loss, claim, damage, liability or action.

This Power of Attorney shall remain in full force and effect until the undersigned is no longer required to file a Schedule 13D or Schedule 13G (including amendments thereto) with respect to the undersigned’s holdings of and transactions in securities issued by Clearwire Corporation, unless earlier revoked by the undersigned in a signed writing delivered to the attorney-in-fact. This Power of Attorney does not revoke any other power of attorney that the undersigned has previously granted.

(Signature Page Follows)

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IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of the date written below.

Exhibit 6

POWER OF ATTORNEY

FOR EXECUTING SCHEDULE 13D AND SCHEDULE 13G

The undersigned hereby constitutes and appoints each of Pamela E. Powers and David K. Schumacher, with full power of substitution, as an undersigned’s true and lawful attorney-in-fact to:

The undersigned hereby grants to each attorney-in-fact full power and authority to do and perform all and every act requisite, necessary or proper to be done in the exercise of any of the rights and powers herein granted, as fully to all intents and purposes as the undersigned might or could do if personally present, with full power of substitution or revocation, hereby ratifying and confirming all that each attorney-in-fact shall lawfully do or cause to be done by virtue of this Power of Attorney and the rights and powers granted herein. The undersigned acknowledges that none of the attorneys-in-fact, in serving in such capacity at the request of the undersigned, is assuming any of the undersigned’s responsibilities to comply with Sections 13(d) or 13(g) of the Exchange Act.

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The undersigned agrees that each attorney-in-fact may rely entirely on information furnished orally or in writing by or at the direction of the undersigned to the attorney-in-fact. The undersigned also agrees to indemnify and hold harmless each attorney-in-fact against any losses, claims, damages or liabilities (or actions in these respects) that arise out of or are based upon any untrue statements or omissions of necessary facts in the information provided by or at the direction of the undersigned, or upon the lack of timeliness in the delivery of information by or at the direction of the undersigned, to the attorneys-in fact for purposes of executing, acknowledging, delivering or filing a Schedule 13D or Schedule 13G (including amendments thereto) and agrees to reimburse each attorney-in-fact on demand for any legal or other expenses reasonably incurred in connection with investigating or defending against any such loss, claim, damage, liability or action.

This Power of Attorney shall remain in full force and effect until the undersigned is no longer required to file a Schedule 13D or Schedule 13G (including amendments thereto) with respect to the undersigned’s holdings of and transactions in securities issued by Clearwire Corporation, unless earlier revoked by the undersigned in a signed writing delivered to the attorney-in-fact. This Power of Attorney does not revoke any other power of attorney that the undersigned has previously granted.

(Signature Page Follows)

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IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of the date written below.

Exhibit 7

POWER OF ATTORNEY

FOR EXECUTING SCHEDULE 13D AND SCHEDULE 13G

The undersigned hereby constitutes and appoints each of Pamela E. Powers and David K. Schumacher, with full power of substitution, as an undersigned’s true and lawful attorney-in-fact to:

The undersigned hereby grants to each attorney-in-fact full power and authority to do and perform all and every act requisite, necessary or proper to be done in the exercise of any of the rights and powers herein granted, as fully to all intents and purposes as the undersigned might or could do if personally present, with full power of substitution or revocation, hereby ratifying and confirming all that each attorney-in-fact shall lawfully do or cause to be done by virtue of this Power of Attorney and the rights and powers granted herein. The undersigned acknowledges that none of the attorneys-in-fact, in serving in such capacity at the request of the undersigned, is assuming any of the undersigned’s responsibilities to comply with Sections 13(d) or 13(g) of the Exchange Act.

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The undersigned agrees that each attorney-in-fact may rely entirely on information furnished orally or in writing by or at the direction of the undersigned to the attorney-in-fact. The undersigned also agrees to indemnify and hold harmless each attorney-in-fact against any losses, claims, damages or liabilities (or actions in these respects) that arise out of or are based upon any untrue statements or omissions of necessary facts in the information provided by or at the direction of the undersigned, or upon the lack of timeliness in the delivery of information by or at the direction of the undersigned, to the attorneys-in fact for purposes of executing, acknowledging, delivering or filing a Schedule 13D or Schedule 13G (including amendments thereto) and agrees to reimburse each attorney-in-fact on demand for any legal or other expenses reasonably incurred in connection with investigating or defending against any such loss, claim, damage, liability or action; provided, however, that the recourse under the foregoing indemnity shall be limited to the assets of the undersigned except in the case of gross negligence, actual fraud or willful misconduct.

This Power of Attorney shall remain in full force and effect until the undersigned is no longer required to file a Schedule 13D or Schedule 13G (including amendments thereto) with respect to the undersigned’s holdings of and transactions in securities issued by Clearwire Corporation, unless earlier revoked by the undersigned in a signed writing delivered to the attorney-in-fact. This Power of Attorney does not revoke any other power of attorney that the undersigned has previously granted.

(Signature Page Follows)

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IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of the date written below.