Fujitsu Corporation

Fujitsu Vlsi Limited

Kenichi Sato

Moriaki Mizuno

Tomio Ueda

Kouju Aoki

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.

Output level automatic control apparatus

An input signal is provided at first input terminals of a plurality of parallel AND gates in a delay time control circuit. A digital signal from a decoder having a plurality of bits is coupled to second input terminals of the AND gates with one bit coupled per AND gate. The decoder outputs a signal having an a high level in response to an external input control signal. Output signals from the AND gates are coupled to inputs of a plurality of serially connected OR gates.

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Kasugai, Japan

Kenichi Sato