Amplifier device
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorPaulus Thomas van Zeijl
Life of this patent
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Abstract
An amplifier device, including: at least one input contact, an amplifier section for amplifying a signal presented at said input contacts whereby an amplified signal is obtained; said amplifier section being connected to said input contact; a bias current source connected to said amplifier section for providing a bias current which at least partially controls the gain of the amplifier section, at least one output contact connected to the amplifier section, for receiving the amplified signal from the amplifier section and transmitting the amplified signal further. The bias current source is an alternating current source having an adjustable duty cycle.
Claims9
An amplifier device comprising:
- at least one input contact,
- an amplifier section connected to said at least one input contact for amplifying a signal presented at said at least one input contact whereby an amplified signal is obtained;
- a bias current source connected to said amplifier section for providing a bias current which at least partially controls the gain of the amplifier section,
- at least one output contact connected to the amplifier section, for receiving the amplified signal from the amplifier section and transmitting the amplified signal further,
- wherein the bias current source is an alternating current source having an adjustable duty cycle, said alternating current source being directly connected to the amplifier section.
A method for controlling the gain of an amplifier, comprising:
- determining a required gain of the amplifier;
- tuning a duty-cycle of an alternating bias current such that the time average of the alternating bias current is substantially equal to the bias current corresponding to the required gain, and
- generating a bias current corresponding to the required gain by generating said alternating bias current having said tuned duty-cycle, which alterating bias current is directly provided to the amplifier.
Dependencies are inferred from the claim text.