Optimization of a Multi-port Amplifier Using a Least Squares Evolutionary Relaxation Method
A satellite designed for mobile telecommunications applications may contain a large aperture reflector fed by an array at its principle focus. Each radiator element of the array has a one-to-one correspondence with a spot on the earth, so that radiation patterns are pointed at different locations on the Earth by different combinations of elements. Before the signals arrive at the array with their specified complex weights they must undergo amplification. This can be provided by a beam forming network composed of between 10 and 20 multiport amplifiers (MPA). The object of this paper is to describe an optimization method that will improve the performance of the beam forming network
Synthesis of SAR radiation patterns incorporating mutual coupling by using genetic methods
This paper presents a technique for synthesising the element excitations of an N-element linear array of radiating elements, given a required far-field beam shape template. It also performs the synthesis in the presence of mutual coupling across the array. This method uses an evolutionary or genetic algorithm to search and locate the best solution to the problem. The method takes into account additional aperture constraints including amplitude range or uniform amplitude taper. It can also optimise for simultaneous synthesis of transmit and receive radiation patterns commensurate with standard SAR operation. It also presents some synthesised complementary Tx and Rx patterns and their corresponding measured results. >
Use of a specific antiserum for renin detection in human kidney.
The use of anti-human renin antibodies made possible the intrarenal localization of renin in human kidney by immunofluorescence. In normal kidney, only some juxtaglomerular apparatus (JGA) were fluorescent. In these JGA, granular or diffuse fluorescence was only seen in afferent arterioles and was not present in all cells. In the ischemic areas of partially infarcted kidney, fluorescence was seen in all JGA and in interlobular arteries. In these arteries the most eccentric cells were often the most positive. In the nonischemic areas of the same kidneys, fluorescence was not seen in JGA, but was observed in proximal tubular cells, suggesting the reabsorption of filtered renin at this site.