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                                                                   EXHIBIT 10.21

                              FORBEARANCE AGREEMENT


     This Forbearance Agreement (the "Agreement"), made this 8th day of
November, 2002, by and among Bank One, N.A., formerly known as American National
Bank & Trust Company of Chicago (the "BANK"), and M-Wave, Inc., a Delaware
corporation, and Poly Circuits, Inc., an Illinois corporation (M-Wave, Inc. and
Poly Circuits Inc. hereinafter collectively referred to as the "BORROWER").

                                   WITNESSETH:

          WHEREAS, Borrower has entered into a Loan Agreement, dated as of July
1, 2001 (as amended from time to time, the "LOAN AGREEMENT") with the Illinois
Development Finance Authority (the "ISSUER"), a public body corporate and
politic, pursuant to which Loan Agreement the Issuer has agreed to lend to the
Borrower $8,100,000.00 to finance the costs of the Project (as defined in the
Loan Agreement), which loan is evidenced by the PROMISSORY NOTE (as defined in
the Loan Agreement).

          WHEREAS, the Issuer entered into a Trust Indenture, dated as of July
1, 2001 (as amended from time to time, the "INDENTURE"), naming American
National Bank and Trust Company of Chicago, an Illinois banking corporation, now
known as Bank One, N.A., as trustee (together with any successor trustee under
the Indenture, the "TRUSTEE").

          WHEREAS, Pursuant to the Loan Agreement and the Indenture, the Issuer
issued its $8,100,000 Variable Rate Demand Industrial Development Revenue Bonds
(M-Wave Inc. Project), Series 2001 (the "BONDS");

     WHEREAS, to provide for payment of the Bonds, the Bank issued the
Irrevocable Letter of Credit in the amount of $8,199,864 dated July 26, 2001 in
favor of American National Bank and Trust Company of Chicago, as Trustee (the
"LETTER OF CREDIT");

     WHEREAS, Borrower is obligated to reimburse the Bank for draws under the
Letter of Credit pursuant to the Reimbursement Agreement dated as of July 26,
2001 between Bank and Borrower (the "REIMBURSEMENT AGREEMENT");

     WHEREAS, Borrower is in default under the Reimbursement Agreement because
of its failure to comply with the financial ratios set forth in Section 7.5
thereof;

     WHEREAS, Borrower has requested that Bank forbear from exercising certain
of its remedies under the Reimbursement Agreement, and Bank is willing to do so
subject to the terms and conditions hereof.

     NOW, THEREFORE, in consideration of the foregoing and the mutual
undertakings herein set forth, the parties hereto agree as follows:

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     1. Recitals. The foregoing recitals are incorporated by reference into this
Agreement and shall be binding upon the parties.

     2. Forbearance. Provided Borrower complies with all of the terms and
conditions hereof in the time provided therefor, Bank agrees to forbear for the
period from the date hereof to December 31, 2002 from pursuing its rights under
the Reimbursement Agreement to give written notice to the Trustee as provided in
Section 601 of the Indenture to accelerate the maturity of the Bonds in
accordance with Section 602 of the Indenture, and to declare all of the
Obligations (as defined in the Reimbursement Agreement) immediately payable at
the Default Rate (as defined in Section 3.1(b) of the Reimbursement Agreement.
Nothing herein or in any negotiations in connection herewith shall be deemed to
be a waiver of any other or future default by Borrower, nor shall any cure by
Borrower of the current defaults terminate or invalidate any of the provisions
hereof.

     3. Covenants of Borrowers. Borrower agrees that:

(a)  Borrower shall not request and agrees that from the date hereof it shall
     not be entitled to any disbursement from the Project Fund for Costs of the
     Project or any other purpose without the prior written consent of the Bank,
     which consent shall be at Bank's sole discretion, whether or not an Event
     of Default (as defined in the Reimbursement Agreement) exists at the time
     of any request for such consent.

(b)  Borrower shall take all action necessary to cause the Project Fund to be
     and remain pledged to Bank to secure the Obligations of Borrower to Bank
     under the Reimbursement Agreement, including executing a Pledge Agreement
     in form and substance satisfactory to Bank.

(c)  No other Event of Default shall occur under the Reimbursement Agreement.

     4. Waiver and Release of Claims. Borrower represents to the Bank that it
has no defenses, setoffs, claims or counterclaims of any kind or nature
whatsoever against the Bank in connection with the Bonds, the Letter of Credit,
the Reimbursement Agreement or any of the Loan Documents (as defined in the
Reimbursement Agreement), or any action taken or not taken by the Bank with
respect thereto. Without limiting the generality of the foregoing, and in
consideration of Bank's agreements hereunder, Borrower hereby releases and
forever discharges the Bank, its affiliates and each of their officers, agents,
employees, attorneys, insurers, successors and assigns (collectively the
"Released Parties"), from and against any and all liabilities, rights, claims,
losses, expenses or causes of action, known or unknown, arising out of any
action or inaction by any of the Released Parties to the date hereof with
respect to the Bonds, the Indenture, the Letter of Credit, the Reimbursement
Agreement or any of the Loan Documents (as defined in the Reimbursement
Agreement), or this Agreement, no matter in any way related thereto or arising
in conjunction therewith. The Borrower also

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waives, releases and forever discharges the Released Parties and each of them
from and against any and all known or unknown rights to setoff, defenses,
claims, counterclaims, causes of action, and any other bar to the enforcement of
this Agreement, the Bonds, the Indenture, the Letter of Credit, the
Reimbursement Agreement or any of the Loan Documents (as defined in the
Reimbursement Agreement).

     5. Disclaimer of Reliance. Borrower expressly disclaims any reliance on any
oral representation made by the Released Parties or any of them in respect to
the subject matter of this Agreement. Borrower acknowledges and agrees that the
Bank is specifically relying upon the representations, warranties, releases and
agreements contained herein, and that this Agreement is being executed by
Borrower and delivered to the Bank as an inducement to the Bank to forbear from
exercising remedies available to the Bank.

     6. Notice. All notices and demands under and with respect to this
Agreement, if any, shall be in writing and shall be given as provided in the
reimbursement Agreement, except that notices to Bank shall be directed to:

                           Bank One, N.A.
                           120 South LaSalle Street
                           Chicago, Illinois 60603
                           Attn.: Peter J. Flory
                                  Sixth Floor

     IN WITNESS WHEREOF, the parties named below have caused this Agreement to
be executed as of the day and year first above written.

                           LENDER:

                                BANK ONE, N.A.


                                By:
                                   --------------------------------
                                Name:
                                     ------------------------------
                                Title:
                                      -----------------------------

                           BORROWERS:

                                M-WAVE, INC.


                                By:
                                   --------------------------------
                                Name:
                                     ------------------------------
                                Title:
                                      -----------------------------

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                                POLY CIRCUITS, INC.


                                By:
                                   --------------------------------
                                Name:
                                     ------------------------------
                                Title:
                                      -----------------------------