Exhibit 21
SUBSIDIARIES
The following is a list of the significant and other active subsidiaries of the Company as of September 17, 2008:
Significant Subsidiaries	Jurisdiction of Incorporation
Telecommunications Transmission Segment
Comtech EF Data Corp.	Delaware
Comtech Systems, Inc.	Delaware
Mobile Data Communications Segment
Comtech Mobile Datacom Corporation	Delaware
RF Microwave Amplifiers Segment
Comtech Xicom Technology, Inc.	California
Other Active Subsidiaries
Telecommunications Transmission Segment
Comtech Antenna Systems, Inc.	Delaware
Comtech AHA Corporation	Delaware
Memotec Inc. (a subsidiary of Comtech EF Data Corp.)	New Brunswick, Canada
Comtech Tiernan Video, Inc.	Delaware
Beijing Comtech EF Data Equipment Repair Service, Co., Ltd.	China
RF Microwave Amplifiers Segment
Comtech PST Corp.	New York
Xicom Technology Europe, Ltd.	United Kingdom
Mobile Data Communications Segment
Comtech AeroAstro, Inc	Delaware