Near-field measurement of active phased array antennas under low-PRF pulsed conditions within milliseconds with a standard HP 8510B

Vector network measurement has been, and is, used in characterizing microwave devices. Until now, vector network analyzers (NWA) were designed to operate with a continuous wave (CW) driving signal. However, an increasingly important class of microwave devices have a requirement not normally associated with standard CW vector network measurement. These devices must be characterized under pulsed-RF conditions. Now vector network analyzers designed for measuring pulsed-RF signals are beginning to become available (Hewlett Packard HP85108A and Wiltron 360-PS20). But since these NWAs are mainly designed for pulse profile measurements and are very costly (also due to the use of two frequency synthesizers), a method has been developed to use a standard CW HP 8510B NWA with one frequency synthesizer for measuring pulsed signals with a low pulse repetition frequency (PRF)