US 5,515,008 AGranted

Output level automatic control apparatus

AssigneeFujitsu Limited

InventorsTomio Ueda, Kenichi Sato

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Abstract

An output level automatic control apparatus suitable for use to keep a transmitted output level of a radio system constant has an objective to prevent an output level above a specified value from being transmitted if an input level abruptly becomes a normal level from a break state, and to stabilize the output level with a simple configuration. The output level automatic control apparatus includes a main amplifier output level feed-back control loop extending from an output side of a main amplifier to a variable attenuator, which main amplifier output level feed-back control loop includes an output level detecting means, a reference value setting means, and a control means controlling the variable attenuator on the basis of a result obtained by comparing a detected output of the main amplifier with a reference value. Said main amplifier output level feed-back loop becomes negative feed-back when the output level of said main amplifier is in the neighborhood of a set value, and becomes positive or zero feed-back when the output level of the main amplifier is smaller than a second set value that is smaller than said set value.

Claims9

Dependent claims

An output level automatic control apparatus comprising:

a variable attenuator arranged on a side of an input of a main amplifier;
a main amplifier output level feed-back control loop extending from a side of an output of said main amplifier to said variable attenuator;
said main amplifier output level feed-back control loop comprising
an output level detecting means detecting an output level of said main amplifier;
a reference value setting means setting a reference value;
a control means outputting a control signal controlling the output level of said main amplifier to said variable attenuator on the basis of a result obtained by comparing the output level of said main amplifier detected by said output level detecting means with the reference value set by said reference value setting means;
said main amplifier output level feed-back control loop becoming negative feed-back when the output level of said main amplifier is in the neighborhood of a set value corresponding to a normal operation condition and becoming positive feed-back when the output level of said main amplifier is smaller than a second set value that is smaller than said set value;
wherein
a gain or an attenuation quantity at the time when no input signal is inputted to said main amplifier is set to be substantially equal to a gain or an attenuation quantity at the time when the output level of said main amplifier is at said set value corresponding to said normal operation condition.

6 more elements

Dependencies are inferred from the claim text.