Abstract: A transconductance amplifier (TCA) implemented with high electron mobility transistors (HEMTs) in a push-pull amplifier output stage provides a voltage controlled constant high output current to loads ranging from 10 m? to 1? with a bandwidth of 25 MHz. A driving stage for the HEMTs is implemented with variable gain amplifiers that amplify the input voltage signal and provide bias for the HEMTs. An automatic gain control may be connected between the TCA output and the variable gain amplifiers to ensure a constant current output for a varying load.

Abstract: A process that allows the removal of fixed-pattern noise in effective images formed by electromagnetic sensor arrays in a light field, which includes at least the following steps: (a) The formation of a digital image from an electromagnetic sensor array; (b) the formation of a light field that must have at least 2×2 digital images of a scene, with a separation distance of at least the size of the effective area of an electromagnetic sensor; and (c) the reconstruction of an image by means of digital refocusing from the light field.

Abstract: A transconductance amplifier (TCA) implemented with high electron mobility transistors (HEMTs) in a push-pull amplifier output stage provides a voltage controlled constant high output current to loads ranging from 10 m? to 1? with a bandwidth of 25 MHz. A driving stage for the HEMTs is implemented with variable gain amplifiers that amplify the input voltage signal and provide bias for the HEMTs. An automatic gain control may be connected between the TCA output and the variable gain amplifiers to ensure a constant current output for a varying load.

Abstract: A process that allows the removal of fixed-pattern noise in effective images formed by electromagnetic sensor arrays in a light field, which includes at least the following steps: (a) The formation of a digital image from an electromagnetic sensor array; (b) the formation of a light field that must have at least 2×2 digital images of a scene, with a separation distance of at least the size of the effective area of an electromagnetic sensor; and (c) the reconstruction of an image by means of digital refocusing from the light field.

Abstract: An anti-parallel loop carrier synchronization circuit for coherent binary phase shift keying (BPSK) demodulation is disclosed. One embodiment comprises an anti-parallel dual phase-locked loop (PLL), which locks the carrier by its upper PLL (0°) and lower PLL (180°) alternately, according to the data bits contained in the received BPSK signal. Demodulation of the data is completed through control of the upper PLL and the lower PLL.