Abstract: An RF inspection tool in for testing RF leakage of a slot radiator antenna array. The inspection tool comprises a vacuum chamber having a cover with a flexible metal diaphragm. The periphery of the cover seals to a base structure by means of an O-ring seal. The flexible diaphragm preferably comprises an aluminum sheet that conforms to the face of the antenna array when a vacuum is created within the tool. The flexible diaphragm has a plurality of flanges bonded thereto that allow access to and provide test points for the radiating slots of the antenna array. The flexible diaphragm is pulled toward the face of the antenna array when a vacuum is formed, and provides a tight seal against the face of the antenna array. The seal prevents RF leakage out of radiator slots of the antenna array. A network analyzer is used to transmit and receive RF energy through the flanges which are disposed adjacent different modules of the antenna array. Crosstalk or electrical leakage is measured using the network analyzer.