<PAGE>

                                                                 EXHIBIT 10.22.1

                      FIRST AMENDMENT TO CREDIT AGREEMENT
                      -----------------------------------
                                        
     THIS FIRST AMENDMENT TO CREDIT AGREEMENT (the "Amendment"), dated as of
                                                    ---------               
December 11, 1997, is entered into by and between POWERWAVE TECHNOLOGIES, INC.
(the "Borrower") and BANK OF AMERICA NATIONAL TRUST AND SAVINGS ASSOCIATION (the
      --------                                                                  
"Bank").
 ----   

                                    RECITALS
                                    --------
                                        
     A.  The Borrower and the Bank are parties to a Credit Agreement dated as of
August 1, 1997 (the "Credit Agreement") pursuant to which the Bank has extended
                     ----------------                                          
certain credit facilities to the Borrower.

     B.  The Borrower has requested that the Bank agree to certain amendments of
the Credit Agreement.

     C.  The Bank is willing to amend the Credit Agreement, subject to the terms
and conditions of this Amendment.

     NOW, THEREFORE, for valuable consideration, the receipt and adequacy of
which are hereby acknowledged, the parties hereto hereby agree as follows:

     1.  Defined Terms.  Unless otherwise defined herein, capitalized terms used
         -------------                                                          
herein shall have the meanings, if any assigned to them in the Credit Agreement.

     2.  Amendments to Credit Agreement.
         ------------------------------ 

        (a) Clause (b) of the exception contained in Section 7.04 of the Credit
Agreement is hereby amended and restated in its entirety so as to read as
follows:

               "(b)  repurchases of the Borrower's stock not to exceed
               $25,000,000 from and after the date hereof."

        (b) Schedule 2 to exhibit A of the Credit Agreement is hereby amended
 and restated in its entirety so as to read as set forth in Schedule 2 attached
 hereto.

     3.  Representations and Warranties.  The Borrower hereby represents and
         ------------------------------                                     
warrants to the Bank as follows:

          (a) No Default or Event of Default has occurred and is continuing.

          (b) The execution, delivery and performance by the Borrower of this
Amendment have been duly authorized by all necessary corporate and other action
and do not and will not require any registration with, consent or approval of,
notice to or action by, any Person (including any governmental authority) in
order to be effective and enforceable. The Credit Agreement as amended by this
Amendment constitutes the legal, 
<PAGE>
 
valid and binding obligations of the Borrower, enforceable against it in
accordance with its respective terms, without defense, counterclaim or offset.

          (c) All representations and warranties of the Borrower contained in
the Credit Agreement are true and correct.

          (d) The Borrower is entering into this Amendment on the basis of its
own investigation and for its own reasons, without reliance upon the Bank or any
other Person.

     4.  Effective Date.  This Amendment will become effective as of the date
         --------------                                                      
first above written (the "Effective Date"), provided that each of the following
                          --------------    -------- ----                      
conditions precedent is satisfied:

         (a) The Bank has received from the Borrower a duly executed original
(or, if elected by the Bank, an executed facsimile copy) of this Amendment.

         (b) The Bank has received from the Borrower a copy of a resolution
passed by the board of directors of such corporation, certified by the Secretary
or an Assistant Secretary of such corporation as being in full force and effect
on the date hereof, authorizing the execution, delivery and performance of this
Amendment.

     5.  Reservation of Rights.  The Borrower acknowledges and agrees that the
         ---------------------                                                
execution and delivery by the Bank of this Amendment shall not be deemed to
create a course of dealing or otherwise obligate the Bank to forbear or execute
similar amendments under the same or similar circumstances in the future.

     6.  Miscellaneous.
         ------------- 

         (a) Except as herein expressly amended, all terms, covenants and
provisions of the Credit Agreement are and shall remain in full force and effect
and all references therein to such Credit Agreement shall henceforth refer to
the Credit Agreement as amended by this Amendment. This Amendment shall be
deemed incorporated into, and a part of, the Credit Agreement.

         (b) This Amendment shall be binding upon and inure to the benefit of
the parties hereto and thereto and their respective successors and assigns. No
third party beneficiaries are intended in connection with this Amendment.

         (c) This Amendment shall be governed by and construed in accordance
with the law of the State of California.

         (d) This Amendment may be executed in any number of counterparts, each
of which shall be deemed an original, but all such counterparts together shall
constitute but one and the same instrument. Each of the parties hereto
understands and agrees that this document (and any other document required
herein) may be delivered by any party thereto either in the form of an executed
original or an executed original sent by

                                       2
<PAGE>
 
facsimile transmission to be followed promptly by mailing of a hard copy
original, and that receipt by the Bank of a facsimile transmitted document
purportedly bearing the signature of the Borrower shall bind the Borrower with
the same force and effect as the delivery of a hard copy original. Any failure
by the Bank to receive the hard copy executed original of such document shall
not diminish the binding effect of receipt of the facsimile transmitted executed
original of such document which hard copy page was not received by the Bank.

         (e) This Amendment, together with the Credit Agreement, contains the
entire and exclusive agreement of the parties hereto with reference to the
matters discussed herein and therein. This Amendment supersedes all prior drafts
and communications with respect hereto.

         (f) If any term or provision of this Amendment shall be deemed
prohibited by or invalid under any applicable law, such provision shall be
invalidated without affecting the remaining provisions of this Amendment or the
Credit Agreement, respectively.

         (g) Borrower covenants to pay to or reimburse the Bank, upon demand,
for all reasonable costs and expenses (including allocated costs of in-house
counsel) incurred in connection with the development, preparation, negotiation,
execution and delivery of this Amendment.

                                       3
<PAGE>
 
IN WITNESS WHEREOF, the parties hereto have executed and delivered this
Amendment as of the date first above written.


                              POWERWAVE TECHNOLOGIES, INC.



                              By: /s/  KEVIN T. MICHAELS
                                  -----------------------
                              Name:  Kevin T. Michaels
                              Title: Vice President, Finance and Chief
                                     Financial Officer



                              BANK OF AMERICA NATIONAL
                              TRUST AND SAVINGS
                              ASSOCIATION


                              By: /s/ DEBRA G. STAIGER
                                  --------------------
                              Name:   Debra G. Staiger
                              Title:  Vice President

                                       4
<PAGE>
 
                                  SCHEDULE 2
                                  ----------

                         To the Compliance Certificate
                                 ($ in 000's)/1/
                                                 Date:  _________________, 199__
                                                                                
                                                     For the fiscal quarter/year
                                                     Ended ______________, 199__

<TABLE>
<CAPTION>
 

                                                        Actual               Required/Permitted
                                                        ------               ------------------
<S>                                                     <C>                  <C> 
1.     Section 7.01(h) Other                                                 Not to exceed $2,000,000
       -----------------------
       Unsecured Indebtedness.
       -----------------------
 
       Unsecured Indebtedness (other than
       types listed in 7.01(a) through (g))

2.     Section 7.03 Acquisitions.                                            Not to exceed $10,000,000
       --------------------------
       Cash and debt consideration paid for
       acquisitions made from and after August 1, 1997

3.     Section 7.04(b) Stock Repurchases.
       ----------------------------------
       Stock repurchases from and after August 1,                            Not to exceed $25,000,000
       1997                        
 
4.     Section 7.10 Quick Ratio.
       -------------------------
       The ratio of:
 
       A.  the sum of unencumbered:
  
         (i)     cash

                     plus
                     ----
 
         (ii)    short-term investments
                  
                     plus
                     ----
 
         (iii)   marketable securities not
                 classified as long-term
                 investments
 
                     plus
                     ----
         (iv)    current accounts receivable (net
                 of bad debt reserves) 
                 (i)+(ii)+(iii)+(iv)  =
                                       
       B.  current liabilities (including                                    Not less than 1.25 to 1.00
           Advances under the Credit
           Agreement)  

                  A
                 --                =                    ______________
                  B                    
                                                  
5.     Section 7.11 Tangible Net Worth.
       -------------------------------
</TABLE> 
 
----------------------------------

/1/ All amounts determined on a consolidated basis and computed in accordance
    with GAAP, consistently applied.

                                       5
<PAGE>
 
<TABLE> 
<CAPTION> 

<S>                                           <C>     
                                              Not to be less than the sum of:            
                                                                                         
  Tangible Net Worth:                         Tangible Net Worth as of 3/30/97:          
                                                                                         
    (i)  gross book value of                  (i)  gross book value of assets            
         assets                                                                          
                                                                                         
             less                                      less                              
             ----                                      ----                              
    (ii)  goodwill, patents,                  (ii)  goodwill, patents,                   
          trademarks, trade                         trademarks, trade names,             
          names, organization                       organization expense,                
          expense, treasury                         treasury stock,                      
          stock, unamortized                        unamortized debt discount            
          debt discount and                         and expense, deferred                
          expense, deferred                         research and development             
          research and                              costs, deferred marketing            
          development costs,                        expenses, other deferred             
          deferred marketing                        charges and other like               
          expenses, other                           intangibles                          
          deferred charges and                                                           
          other like intangibles                                                         
                                                                                         
            less                                       less                              
            ----                                       ----                              
                                                                                         
    (iii)  monies due from                    (iii)  monies due from                     
           affiliates, officers,                     affiliates, officers,               
           directors, or                             directors, or                       
           shareholders of the                       shareholders of the                 
           Borrower or its                           Borrower or its                     
           Subsidiaries                              Subsidiaries                        
                                                                                         
             less                                      less                              
             ----                                      ----                              
                                                                                         
    (iv)  reserves applicable to              (iv)  reserves applicable to               
          assets (including                         assets (including reserves           
          reserves for                              for depreciation and                 
          depreciation and                          amortization)                        
          amortization)                                                                  
                                                                                         
            less                                      less                               
            ----                                      ----                               
                                                                                         
    (v)  all liabilities                      (v)  all liabilities (including            
         (including accrued                        accrued and deferred                  
         and deferred income                       income taxes and                      
         taxes and                                 subordinated liabilities              
         subordinated                                                                    
         liabilities                                                                     
                                                                                         
     (i)-(ii)-(iii)-(iv)-(v) =                  (i)-(ii)-(iii)-(iv)-(v) =                
                                                                          ===============
</TABLE> 

------------------------
/2/ Calculation will need to be done for first compliance certificate only;
thereafter, this number will be inserted.

                                       6
<PAGE>
 
6.    Section 7.12 Total
      ------------------
      Liabilities to Tangible Net
      ---------------------------
      Worth.
      -------
 
      The ratio of
       
      A.  Total liabilities
          (including Advances under the
          Credit Agreement)
      

      B.  Tangible Net Worth:
          (from #5 above)      
                   A
                  --                              Not greater than 0.80 to 1.00
                   B                =              
 
7.     Section 7.13 Consecutive
       ------------------------
       Quarterly Losses; Losses in
       ----------------------------
       One Quarter. 
       ----------- 
       
       A.  Operating income (loss)                No loss if loss in immediately
           for fiscal quarter                     preceding fiscal quarter; no
                                                  loss in excess of 5% times
                                                  Tangible Net Worth (from #5
                                                  above)
                                                                
       B.  Net income (loss) for                  No loss if loss in immediately
           fiscal quarter                         preceding fiscal quarter; no
                                                  loss in excess of 5% times
                                                  Tangible Net Worth (from #5
                                                  above)

                                       7