Procedure for operating a high frequency amplifier

• US 20060192619A1
• Filed: 02/15/2006
• Published: 08/31/2006
• Est. Priority Date: 02/16/2005
• Status: Active Grant

• Current Assignee: Airbus Defence and Space GmbH
• Original Assignee: EADS Deutschland GmbH (Airbus SE)
• Inventors: Huber, Georg, Salomon, Andreas, Hoffmann, Gebhard
• Granted Patent: US 7,362,181 B2
• Time in Patent Office: Days
• US Class Current: 330/298
• CPC Class Codes: H03F 1/0261 with control of the polarisation voltage or current, e.g. gliding Class A
• CPC Class Codes: H03F 1/3247 using feedback acting on predistortion circuits H03F1/3264 takes precedence
• CPC Class Codes: H03F 1/3282 Acting on the phase and the amplitude of the input signal
• CPC Class Codes: H03F 2200/481 A resistor being used as sensor
• CPC Class Codes: H03F 3/193 with field-effect devices H03F3/195 takes precedence
• CPC Class Codes: H03F 3/195 in integrated circuits

Abstract

A procedure for operation of a high frequency amplifier having a power transistor—amplifier stage designed as a source or emitter circuit for amplifying a gate or base side high frequency signal supplied over an input interface network E which signal is amplified at the drain or collector side and output via an output interface network. A device for the measurement of the drain or collector current I_D is connected at the amplifier stage on the drain or collector side and a final control element is connected on the gate or base side. A pre-adjustable desired value W_SOLL and an actual value W_IST corresponding to the drain or collector current are input to the final control element, which adjusts the gate voltage or the base current so that the drain or collector current I_D is brought to the desired value W_SOLL. At a constant input power P_IN of the high frequency amplifier, the envelope curve of the output signal RF_OUT is modulated by the desired value W_SOLL.

Claims

1. A process for operating a high frequency amplifier having a source or emitter designed power transistor—

amplifier stage for amplification of a high frequency signal that is input to a gate or base terminal via an input interface network E, which signal is amplified at a drain or collector terminal and output via an output interface network;

said process comprising;

at a drain or collector terminal, providing a device for measuring the drain or collector current;

connecting a final control element at a gate or base terminal;

feeding to the final control element a corresponding desire value W_SOLL and an actual value W_IST corresponding to drain or collector current I_D; and

at a constant input power P_IN of the high frequency amplifier, modulating an envelope curve of the output signal RF_OUT by the desired value W_SOLL.

2. The process according to claim 1, further comprising:

a pulse generator feeding to the final control element a pulse with a pre-adjustable amplitude and pulse form.

3. The process according to claim 2 for implementation of a linear polar amplifier, in which phase information in the signal source and amplitude information in the high frequency amplifier are modulated, whereby the desired value W_SOLL is adjusted to correspond to the amplitude information.

4. A high frequency amplifier circuit, comprising:

a source or emitter designed power transistor stage;

an input interface network for supplying a high frequency input signal to a gate or base terminal of said power transistor stage;

a current sensing device for measuring drain or collector current of said power transistor stage;

a final control element having a first input connected to said current sensing device for receiving a signal indicative of an actual value of drain or collector current, a second input for receiving a desired value of said drain or collected current, and an output connected to supply a control signal to a gate or base terminal of said power transistor stage; and

means, operable at a constant input power of the high frequency amplifier, for modulating an envelope curve of the output signal by the desired value of the drain or collector current.

5. The amplifier circuit according to claim 4, further comprising a pulse generator connected to supply to said input of said final control element a pulse with a pre-adjustable amplitude and pulse form.