Exhibit 10.1

FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT

FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT, dated as of January 6, 2012 and effective as of the First Amendment Effective Date (as defined below) (this “Amendment”), among API TECHNOLOGIES CORP., a Delaware corporation (the “Borrower”), MORGAN STANLEY SENIOR FUNDING, INC., as Administrative Agent under the Credit Agreement referred to below (in such capacity, the “Administrative Agent”), and the Lenders (as defined below) party hereto.

WHEREAS, the Borrower, Morgan Stanley Senior Funding, Inc., as Administrative Agent, and the lenders from time to time party thereto (the “Lenders”) have entered into that certain Amended and Restated Credit Agreement, dated as of June 27, 2011 (as amended or otherwise modified from time to time prior to the date hereof, the “Credit Agreement”).

WHEREAS, the parties hereto wish to amend the terms of the Credit Agreement as set forth herein.

THEREFORE, in consideration of the foregoing and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto hereby agree as follows:

SECTION 1. Defined Terms. Capitalized terms used herein and not otherwise defined herein have the meanings assigned to them in the Credit Agreement.

SECTION 2. Amendment to Credit Agreement. Effective as of the First Amendment Effective Date (as defined below), the Credit Agreement is hereby amended as follows: (a) the following new subclause (xii) is in inserted after subclause (xi) of clause (A) of the definition of “Consolidated EBITDA”: “and (xii) solely for the Test Period ended November 30, 2011 (and not any subsequent Test Periods) and solely for the purpose of determining compliance with Sections 10.07, 10.08, and 10.09 as demonstrated in the calculations set forth in certificates delivered pursuant to Section 9.01(e) of the Credit Agreement, pro forma projected synergies and cost savings related to the Acquisition in the amount of $2,300,000 for the Fiscal Quarter ended August 31, 2011 and $2,300,000 for the Fiscal Quarter ended November 30, 2011,”; (b) upon the receipt by the Borrower or any Subsidiary of Net Sale Proceeds from a Sale Leaseback of any real property, an amount equal to 100% of such Net Sale Proceeds shall promptly be applied as a mandatory prepayment in accordance with Sections 5.02(h) and 5.02(i); and (c) solely for the Test Period ended November 30, 2011, for the purpose of calculating the Interest Coverage Ratio pursuant to Section 10.08 of the Credit Agreement, Consolidated EBITDA shall be determined on a Pro Forma Basis in accordance with clause (iii) of the definition of “Pro Forma Basis” in the Credit Agreement.

SECTION 3. Representations and Warranties. To induce the other parties hereto to enter into this Amendment, the Borrower represents and warrants to each other party hereto that, as of the date hereof:

(a) this Amendment has been duly authorized, executed and delivered by it and each of this Amendment and the Credit Agreement, as amended hereby, constitute its legal, valid and binding obligation, enforceable against it in accordance with its terms, except as may be limited by applicable bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium or similar laws of general applicability relating to or limiting creditors’ rights generally and subject to general principles of equity, regardless of whether considered in a proceeding in equity or at law; and

(b) after giving effect to this Amendment and the transactions contemplated hereby, no Default or Event of Default has occurred and is continuing.

SECTION 4. Effectiveness. Upon satisfaction the following condition, the parties hereto agree that this Amendment shall be deemed effective as of November 30, 2011 (the “First Amendment Effective Date”):

(i) The Administrative Agent shall have received duly executed counterparts hereof that, when taken together, bear the signatures of the Borrower and Lenders constituting Required Lenders.

SECTION 5. Effect of Amendment. (a) Except as expressly set forth herein (including, for the avoidance of doubt, Section 4 hereof, which is intended to make the amendments set forth in Section 2 hereof effective as of the First Amendment Effective Date), this Amendment shall not by implication or otherwise limit, impair, constitute a waiver of or otherwise affect the rights and remedies of the Lenders or the Agents under the Credit Agreement or any other Credit Document, and shall not alter, modify, amend or in any way affect any of the terms, conditions, obligations, covenants or agreements contained in the Credit Agreement or any other provision of the Credit Agreement or of any other Credit Document, all of which are ratified and affirmed in all respects and shall continue in full force and effect as amended hereby. Nothing herein shall be deemed to entitle the Borrower to a consent to, or a waiver, amendment, modification or other change of, any of the terms, conditions, obligations, covenants or agreements contained in the Credit Agreement or any other Credit Document in similar or different circumstances.

(b) On and after the First Amendment Effective Date, each reference in the Credit Agreement to “this Agreement”, “hereunder”, “hereof”, “herein”, or words of like import, and each reference to the Credit Agreement in any other Credit Document shall be deemed a reference to the Credit Agreement as amended hereby. This Amendment shall constitute a “Credit Document” for all purposes of the Credit Agreement and the other Credit Documents.

SECTION 6. Affirmation. By executing and delivering a counterpart hereof, the Borrower hereby agrees that all Loans shall be guaranteed and secured pursuant to and in accordance with the terms and provisions of each of the U.S. Guaranty and Collateral Agreement and the Canadian Guaranty and Collateral Agreement and the other Security Documents in accordance with the terms and provisions thereof.

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SECTION 7. GOVERNING LAW. THIS AMENDMENT SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.

SECTION 8. Counterparts. This Amendment may be executed in one or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. Delivery by facsimile or other electronic imaging means of an executed counterpart of a signature page to this Amendment shall be effective as delivery of an original executed counterpart of this Amendment.

SECTION 9. Headings. Section headings herein are included for convenience of reference only and shall not affect the interpretation of this Amendment.

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IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed by their duly authorized officers, all as of the date and year first above written.

[Signature Page to First Amendment to Amended and Restated Credit Agreement]

[Signature Page to First Amendment to Amended and Restated Credit Agreement]

[Signature Page to First Amendment to Amended and Restated Credit Agreement]

[Signature Page to First Amendment to Amended and Restated Credit Agreement]

[Signature Page to First Amendment to Amended and Restated Credit Agreement]

[Signature Page to First Amendment to Amended and Restated Credit Agreement]

[Signature Page to First Amendment to Amended and Restated Credit Agreement]

[Signature Page to First Amendment to Amended and Restated Credit Agreement]

[Signature Page to First Amendment to Amended and Restated Credit Agreement]

[Signature Page to First Amendment to Amended and Restated Credit Agreement]