US 5,963,095 AGranted

Amplifier circuit, a transmitter and a wireless telephone

AssigneeU.S. Philips Corporation

InventorHendrik A. Visser

Life of this patent

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Abstract

An amplifier circuit, particularly for RF-purposes includes a main current stream of a controllable RF-semiconductor device having a control input, a control means having a control output coupled to the control input for controlling the main current stream, and a compensation circuit having a compensation output coupled to the control input for compensating the controllable semiconductor device. The compensation circuit is constructed so as to be temporarily active during a period of time wherein the control means do not supply a control output signal to the control input of the controllable semiconductor device. This provides a suitable solution for IC's and for dealing with DC-adjustment disturbances in a low DC-current dissipating manner caused by a lack of pull-down capability when the amplifier circuit operates at very high frequencies or at relatively large amplitudes.

Claims8

Dependent claims

An amplifier circuit comprising:

a controllable semiconductor device with a first main current stream and a control input for controlling a current in the first main current stream,
a control means comprising a semiconductor device with a second main current stream, and a control output coupled to the control input,
a compensation circuit comprising a compensation input to which a compensation signal is supplied which depends on a control output signal supplied by the control means, and a compensation output coupled to the control input for compensating the first controllable semiconductor device, and
a feedback circuit coupled between the second main current stream and the compensation input, which feedback circuit comprises a frequency-dependent component, the compensation circuit being temporarily active during a period of time wherein the control means do not supply the control output signal to the control input of the controllable semiconductor device.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 09/019,645Filed 6 Feb 1998
Priority: EP 972003417 Feb 1997
Granted: 5 Oct 1999
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H03F 1/0261
In transistor amplifiers: with control of the polarisation voltage or current, e.g. gliding Class A
H03F 3/50
Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements: amplifiers in which input is applied to, or output is…
H03F 2200/24
Indexing scheme relating to amplifiers: the supply or bias voltage or current at the source side of a FET being continuously controlled by a…
H03F 2203/5012
Indexing scheme relating to amplifiers in which input being applied to, or output being derived from, an impedance common to input and output…:…