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                                                                   EXHIBIT 10.15


                           LOAN MODIFICATION AGREEMENT

     This Loan Modification Agreement is entered into as of October 30, 1998, by
and between Celeritek, Inc. ("Borrower") and Silicon Valley Bank ("Bank") whose
address is 3003 Tasman Drive, Santa Clara, CA 95054.

1.   DESCRIPTION OF EXISTING INDEBTEDNESS: Among other indebtedness which may be
owing by Borrower to Bank, Borrower is indebted to Bank pursuant to, among other
documents, an Amended and Restated Loan and Security Agreement, dated September
23, 1997, as may be amended from time to time, (the "Loan Agreement"). The Loan
Agreement provided for, among other things, a Committed Revolving Line in the
original principal amount of Four Million ($4,000,000) and a Committed Equipment
Line in the original principal amount of One Million Dollars ($1,000,000). The
Equipment Line has been modified pursuant to among other documents, a Loan
Modification Agreement dated May 29, 1998, pursuant to, which, among other
things, the principal amount of Equipment Line was increased to One Million Nine
Hundred Forty Four Thousand Four Hundred Forty Four and 44/100 ($1,944,444.44).
Defined terms used but not otherwise defined herein shall have the same meanings
as in the Loan Agreement.

Hereinafter, all indebtedness owing by Borrower to Bank shall be referred to as
the "Indebtedness."

2.   DESCRIPTION OF COLLATERAL AND GUARANTIES. Repayment of the Indebtedness is
secured by the Collateral as described in the Loan Agreement.

Hereinafter, the above-described security documents, together with all other
documents securing repayment of the Indebtedness shall be referred to as the
"Security Documents". Hereinafter, the Security Documents, together with all
other documents evidencing or securing the Indebtedness shall be referred to as
the "Existing Loan Documents".

3.   DESCRIPTION OF CHANGE IN TERMS.

     A.   Modification(s) to Loan Agreement.

          1.   The defined terms as set forth in section 13.1 entitled
               "Definitions" are hereby amended and/or incorporated to read as
               follows:

               "Borrowing Base" is 80% of Eligible Accounts as determined by
               Bank from Borrower's most recent Borrowing Base Certificate for
               all Advances in excess of $4,000,000 in the aggregate. All
               Advances up to an Aggregate amount of $4,000,000 shall not be
               subject to the margin requirement of the Borrowing Base. At such
               times as Advances exceed $4,000,000, all outstanding Advances
               under the Committed Revolving Line shall be subject to the
               Borrowing Base at all times thereafter.

               "Collateral" is the property described on Exhibit A (attached
               hereto).

               "Committed Revolving Line" is a Credit Extension of up to
               $6,000,000.

               "Credit Extension" is each Advance, Equipment Advance, Letter of
               Credit, Term Loan, Exchange Contract or any other extension of
               credit by Bank for Borrower's benefit.

               "Debt Service Coverage" is hereby deleted in its entirety.

               "Eligible Accounts" are Accounts in the ordinary course of
               Borrower's business that meet all Borrower's representations and
               warranties in Section 5.2, but Bank may change eligibility
               standards by giving Borrower notice. Unless Bank agrees otherwise
               in writing, Eligible Accounts will not include:


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               (a)  Accounts that the account debtor has not paid within 90 says
                    of invoice date;

               (b)  Accounts for an account debtor, 50% or more of whose
                    Accounts have not been paid within 90 days of invoice date;

               (c)  Credit balances over 90 days from invoice date;

               (d)  Accounts for an account debtor, including Affiliates, whose
                    total obligations to Borrower exceed 25% of all Accounts for
                    the amounts that exceed that percentage, unless Bank
                    approves in writing.

               (e)  Accounts for which the account debtor does not have its
                    principal place of business in the United States;

               (f)  Accounts for which the account debtor is a federal, state,
                    or local government entity or any department, agency, or
                    instrumentality;

               (g)  Accounts for which Borrower owes the account debtor, but
                    only up to the amount owed (sometimes called "contra"
                    accounts payable, customer deposits or credit accounts);

               (h)  Accounts for demonstration or promotional equipment, or in
                    which goods are consigned, sales guaranteed, sale or return,
                    sale on approval, bill and hold, or other terms if account
                    debtor's payment may be conditional;

               (i)  Accounts for which the account debtor is Borrower's
                    Affiliate, officer, employee, or agent;

               (j)  Accounts in which the account debtor disputes liability or
                    makes any claim and Bank believes there may be a basis for
                    dispute (but only up to the disputed or claimed amount), or
                    if the Account Debtor is subject to any Insolvency
                    Proceeding, or becomes insolvent, or goes out of business;

               (k)  Accounts for which Bank reasonably determines collection to
                    be doubtful.

               "Permitted Liens" are"

               (a)  Liens existing on the Closing Date and shown on the Schedule
                    or arising under this Agreement or other Loan Documents;

               (b)  Liens for taxes, fees assessments or other government
                    charges or levies either not delinquent or being contested
                    in good faith and for which Borrower maintains adequate
                    reserves on its Books, if they have no priority over any of
                    Bank's security interests;

               (c)  Purchase money Liens (i) on Equipment acquired or held by
                    Borrower or its Subsidiaries incurred for financing the
                    acquisition of Equipment, or (ii) existing on equipment when
                    acquired, if the Lien is confined to the property and
                    improvements and the proceeds of the equipment;

               (d)  Leases or subleases and licenses or sublicenses granted in
                    the ordinary course of Borrower's business and any interest
                    or title of a lessor, licensor or under 


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any lease or
                    license, if the leases, subleases, licenses and sublicenses
                    permit granting Bank a security interest;

               (e)  Liens incurred in the extension, renewal or refinancing of
                    the indebtedness secured by Liens described in (a) through
                    (c), but any extension, renewal or replacement of Lien must
                    be limited to the property encumbered by the existing Lien
                    and the principal amount of the indebtedness may not
                    increase.

               "Revolving Maturity Date" is October 30, 1999.

          2.   Section 2.1 entitled "Advances" is hereby amended in part to
               delete the word "Advances" and replace with the word "Credit
               Extensions".

          3.   Sub-section (a) of Section 2.1.1 entitled "Revolving Advances" is
               hereby amended in its entirety to read as follows:

               Bank will make Advances not exceeding the (i) Committed Revolving
               Line or the Borrowing Base, whichever is less, minus (ii) the
               amount of all outstanding Letters of Credit (including drawn but
               unreimbursed Letters of Credit). Advances of up to $4,000,000
               outstanding in the aggregate may be made without regard to any
               limitation under the Borrowing Base. Amounts borrowed under this
               Section may be repaid and reborrowed during the term of this
               Agreement.

          4.   Section 4.1 entitled "Grant of Security Interest" is hereby
               amended in its entirety to read as follows:

               Borrower grants to Bank a continuing security interest in all
               presently existing and later acquired Collateral to secure all
               Obligations and performance of each of Borrower's duties under
               the Loan Documents. Except for Permitted Liens, any security
               interest will be a first priority security interest in the
               Collateral. If this Agreement is terminated, Bank's lien and
               security interest in the Collateral will continue until Borrower
               fully satisfies its Obligations.

          5.   Section 5.2 entitled "Collateral" is hereby amended in its
               entirety to read as follows:

               Borrower has good title to the Collateral, free of Liens except
               Permitted Liens. The Eligible Accounts are bona fide, existing
               obligations, and the service or property has been performed or
               delivered to the account debtor or its agent for immediate
               shipment to and unconditional acceptance by the account debtor.
               Borrower has no notice of any actual or imminent Insolvency
               Proceeding of any account debtor whose accounts are an Eligible
               Account in any Borrowing Base Certificate. All Inventory is in
               all material respects of good and marketable quality, free from
               material defects.

          6.   Sub-section (c) of Section 6.2 entitled "Financial Statements,
               Reports, Certificates" is hereby incorporated into the Loan
               Agreement to read as follows:

               At such times as Advances are subject to the Borrowing Base,
               within 20 days after the last day of each month, Borrower will
               deliver to Bank a Borrowing Base Certificate signed by a
               Responsible Officer, with aged listings of accounts receivable
               and accounts payable.

               Sub-section (d) of Section 6.2 entitled Financial Statements,
               Reports, Certificates" is hereby incorporated into the Loan
               Agreement to read as follows:


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               Bank has the right to audit Borrower's Collateral at Borrower's
               expense at such times as Advances exceed $4,000,000 and upon an
               Event of Default occurring and continuing.

          7.   Section 6.7 entitled "Financial Covenants" are hereby amended in
               their entirety to read as follows:

               Borrower will maintain as of the last day of each quarter, unless
               otherwise noted:

               (i)  QUICK RATIO. A ratio of Quick Assets to Current Liabilities
                    of at least 2.00 to 1.00.

               (ii) DEBT/TANGIBLE NET WORTH RATIO. A ratio of Total Liabilities
                    less Subordinated Debt to Tangible Net Worth plus
                    Subordinated Debt of not more than 1.00 to 1.00.

               (iii) TANGIBLE NET WORTH. A Tangible Net Worth of at least
                    $32,500,000 through the quarter ending December 31, 1998,
                    decreasing to $31,500,000 thereafter.

               (iv) PROFITABILITY. Borrower shall have a minimum net profit of
                    $1 each quarter, except that Borrower may suffer one
                    quarterly loss, not to exceed $500,000. Notwithstanding the
                    foregoing, Bank will test the covenant beginning with the
                    quarter ending June 30, 1999.

               (v)  MINIMUM CASH. Borrower shall maintain monthly Minimum Cash
                    of at least $4,000,000.

          4.   CONSISTENT CHANGES. The Existing Loan Documents are hereby
               amended wherever necessary to reflect the changes described
               above.

          5.   PAYMENT OF THE LOAN FEE. Borrower shall pay to Bank a fee in the
               amount of Fifteen Thousand Dollars ($15,0 00.00) (the "Loan Fee")
               plus all out-of-pocket expenses.

          6.   NO DEFENSES OF BORROWER. Borrower (and each guarantor and pledgor
               signing below) agrees that it has no defenses against the
               obligations to pay any amounts under the Indebtedness.

          7.   CONTINUING VALIDITY. Borrower (and each guarantor and pledgor
               signing below) understands and agrees that in modifying the
               existing Indebtedness, Bank is relying upon Borrower's
               representations, warranties, and agreements, as set forth in the
               Existing Loan Documents. Except as expressly modified pursuant to
               this Loan Modification Agreement, the terms of the Existing Loan
               Documents remain unchanged and in full force and effect. Bank's
               agreement to modifications to the existing Indebtedness pursuant
               to this Loan Modification Agreement in no way shall obligate Bank
               to make any future modifications to the Indebtedness. Nothing in
               this Loan Modification Agreement shall constitute a satisfaction
               of the Indebtedness. It is the intention of Bank and Borrower to
               retain as liable parties all makers and endorsers of Existing
               Loan Documents, unless the party is expressly released by Bank in
               writing. No maker, endorser, or guarantor will be released by
               virtue of this Loan Modification Agreement. The terms of this
               paragraph apply not only to this Loan Modification Agreement, but
               also to all subsequent loan modification agreements.

          8.   CONDITIONS. The effectiveness of this Loan Modification Agreement
               is conditioned upon (i) Borrower's payment of the Loan Fee (ii)
               Borrower's execution of a UCC Financing Statement covering the
               Collateral and (iii) Bank satisfactory review of a UCC search,
               ascertaining it has a first priority security interest in the
               Collateral.


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     This Loan Modification Agreement is executed as of the date first written
above.

BORROWER:                                  BANK:

CELERITEK, INC.                            SILICON VALLEY BANK


By: /s/ MARGARET SMITH                     By: /s/ JOELLEN ADEMSKI
   ----------------------------------         ----------------------------------

Name:   Margaret Smith                     Name:   Joellen Ademski
     --------------------------------           --------------------------------

Title:  CFO                                Title:  SWP
      -------------------------------            -------------------------------


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