Microwave landing system
AssigneeNEC Corporation
InventorYoshihiko Kuwahara
Life of this patent
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Abstract
A microwave landing system in which a beam scanning antenna is provided with an amplifying function to constitute an active array, a traditional power amplifier and the like are omitted to enhance the reliability of operation. The outputs of phase shifters each being associated with a respective one of radiating elements are connected to 1/2 dividers each having p-i-n diodes at opposite output terminals thereof, and the p-i-n diodes of each 1/2 divider are turned on and off alternately. Output signals are fed to radiating elements and a multiplexer with a minimum of loss.
Claims3
A microwave landing system for feeding predetermined power to an auxiliary antenna, comprising:
- a power divider for dividing power in a distribution ratio which is associated with n radiating elements of a beam scanning antenna;
- n phase shifters individually associated with said n radiating elements for providing fractions of the divided power with phases for effecting beam scanning;
- n variable attenuators individually associated said n phase shifters for providing outputs of said phase shifters with attenuations of predetermined characteristics which are variable depending upon whether or not a beam scanning timing is reached;
- n power amplifiers individually associated with said n variable attenuators for amplifying outputs of said variable attenuators to a predetermined level;
- n 1/2 dividers individually associated with said n power amplifiers for dividing outputs of said power amplifiers into two and each feeding one of resulting two outputs to said radiating element associated with said 1/2 divider, said 1/2 dividers each comprising two p-i-n diodes individually connected between opposite output terminals and ground and turning off said p-i-n diodes connected to said radiating element and turning on the other p-i-n diode at a beam scanning timing;
- and
- a power combiner for combining said other output of said n 1/2 dividers being not connected to said radiating elements in a predetermined format and delivering a resulting combined signal to an auxiliary antenna located outside of said n radiating elements.
Dependencies are inferred from the claim text.