Patent ID: 6603435
Filing Date: 2003-08-05
Classification: H01Q

Abstract:
An active broad band reception antenna system having a passive antenna component (1) with a frequency-dependent effective length le, wherein the output connections are connected to the input connections of an amplifier circuit (21), wherein the amplifier circuit (21) comprises:a field effect transistor (2) coupled to the antenna component for receiving a high frequency reception signal (18); at least one low-loss filter circuit (3) having an input admittance (7), and with blind filtering elements, and connected at its input (6) to a signal source connection of said field effect transistor (2), wherein said high-frequency reception signal (18) is de-coupled on the output (4) of said filter circuit; an active conductance (5) coupled to the output (4) of said low-loss filter circuit (3), wherein said blind elements of said low-loss filter circuit (3) are selected so that the frequency dependence of the real component G of the input admittance (7) acting on said input (6) of said at least one low-loss filter circuit (3) is adjusted so that with the required reception capacity, the frequency curve conditioned by the frequency-dependent effective length le of the passive antenna component (1) is obtained in the high-frequency reception signal (18) within a broad frequency band, and that the amount of the input admittance (7) active on said input (6) of said at least one low-loss filter circuit (3) is adequately low outside of said frequency band so as to block out non-linear effects in the blocked frequency range.