Digital word amplifier for personal communications network - has feedback loop controlling dynamic range together with secondary attenuator before loop detector controlled by burst input

摘要

In the digital word amplifier the output power (Ps) is adjusted and regulated by a regulating loop (3). Digital information of varying amplitude is received and applied to a variable attenuator (2) and then to an amplifier (1). Part of the input signal is coupled (4) to the loop and fed back (9) to control the attenuator. In the loop a detector (5) produces a voltage (Vd) to a control card (8) which is amplified (17) and compared with a reference voltage (Vr) constituted from the input burst signal from the digital words. The difference is fed back to control the attenuator. To keep the detector in a linear region the burst signal is also applied (12) to a logic unit (11) which controls a secondary attenuator (10) in front of the detector. ADVANTAGE - Allows amplifier dynamic range to be increased to 70 dB without penalising response time.