Abstract: A modular radio frequency (RF) device includes N base units, each including a differential segmented array (DSA) tile with a support board and a two-dimensional (2D) array of electrically conductive tapered projections disposed on the support board. Neighboring pairs of the electrically conductive tapered projections form RF pixels. The N DSA tiles are arranged to form an RF aperture. The N base units are programmed to switch the RF aperture between a first operating mode and a second operating mode. In the first operating mode, the N base units are operated as at least two independent subsets with each subset operating as an RF transmitter or receiver independently of the other subsets. In the second operating mode all N base units coherently combine as a single phased array RF transmitter or receiver.

Abstract: A video lighthead mountable to a video camera and having a dimmer control that varies the intensity of the light output from the lighthead using pulse width modulation techniques. A photo sensor measures the intensity of light reflected from a subject in front of the lighthead. The intensity of light output from the lighthead is adjusted by control circuitry in response to changes in measured reflected light intensity to maintain a constant level of illumination. The adjustment is carried out by modifying the duty cycle of a pulse width modulation circuit. The duty cycle adjustment of the pulse width modulation is also used to compensate for supply voltage variations in order to maintain constant light output.