Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Control Loop Structure for Phase Correction

IP.com Disclosure Number: IPCOM000017936D
Original Publication Date: 2001-Oct-01
Included in the Prior Art Database: 2003-Jul-23
Document File: 2 page(s) / 151K

Publishing Venue

Siemens

Related People

Ralf Wendler: AUTHOR [+2]

Abstract

The principle of operation of the control loop struc- ture for phase correction is explained in the following text. The output signal of the pre amplifier (1) is undis- torted because pre amplifier (1) works as class A amplifier. If the final stage input power increases and the output power approaches to the 1dB compression point the output signal is distorted.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 89% of the total text.

Information / Kommunikation

einge-� Control Loop Structure for Phase

Correction

Idee: Ralf Wendler, Berlin;

Jörg Braune, Berlin

The principle of operation� of the control loop struc-ture for phase correction is explained in the followingtext.

The output signal of the� � pre amplifier� (1) is undis-torted� because� pre� amplifier� � (1)� works� as� class� Aamplifier. If� the final stage input power increases andthe output power approaches to the 1dB compressionpoint the output signal is distorted.

This distortion� causes� two� effects.� The� amplitudegain� becomes� smaller� and� the phase differencechanges between output and input of the final stage.

The amplitude problem is solved by an digital am-plitude predistortion,� which� uses� look� up� tables� inorder to correct the amplitude gain.

The phase difference problem is solved by the loopstructure,� which� is� displayed� in� the schematic (seepic.1). If the phase angle is changing at the outputthen the� power probe� (9) delivers the changed phaseto� the� phase� detector� � (8).� The� undistorted� signalreaches� phase detector� (8) via� power probe� (2), thedelay line� (5) and an� limiter amplifier� (7). The� delayline� (5) compensates the additional delay caused bythe� signal� path� via� phase� shifter � � (3),� final stages,power probe, additional line and limiter amplifier. Inresult the signal delay is equal in both pathes to thephase detector.

The principle operation is as follow. If an phase de-viation appears at the o...