Telefonaktiebolaget Lm Ericsson (publ)

Christian Fager

Mikael Coldrey

Ulf Gustavsson

Thomas Eriksson

Sven Jacobsson

William Hallberg

David Gustafsson

Rob Maaskant

Mustafa Özen

Katharina Hausmair

Marianna Ivashina

Oleg Iupikov

Ibrahim Can Sezgin

Lise Aabel

System including a dual-fed antenna element is designed to present 2×2 port impedances that guarantee high efficiency operation of the main- and auxiliary transistors at peak- and backed off power. The proposed solution eliminates the need for lossy power combining, such as PCB based circuit combining or impedance matching networks between the antenna element and the main- and auxiliary amplifiers. The power from the main- and auxiliary transistors are combined at the circuit level by the antenna element.

Integrated active Doherty antenna transmitter

A linearization device () is disclosed, which is configured to determine pre-distortion parameters associated with a plurality of non-linear amplifiers (), each associated with a non-linear amplifier characteristic. The linearization device comprises determination circuitry (), a first port () and a second port (). The first port is configured to receive a plurality of channel coefficients indicative of channel characteristics of a plurality of communication paths () between the plurality of non-linear amplifiers and a transmit observation receiver (). The second port is configured to receive, from the transmit observation receiver, a sum of transmission signals generated by the plurality of non-linear amplifiers and transferred over the plurality of communication paths. The determination circuitry is configured to determine the pre-distortion parameters based on the received plurality of channel coefficients, the received sum of transmission signals, and a model of the non-linear amplifier characteristics of the non-linear amplifiers. Corresponding arrangement, wireless transmitter node, cloud based server node, method and computer program product are also disclosed.

Linearization of non-linear amplifiers

The disclosure relates to devices, methods, and computer programs in mobile communications in order to reduce signal distortions. Specifically, it relates to a transmitter system which comprises a plurality of signal paths. Each signal path is associated with an input transmission signal. Each signal path comprises an analog portion of the signal path. Each 5 signal path comprises a Dual-Input Digital Predistortion, DI DPD, module. The DI DPD is configured to provide a predistorted input transmission signal to the analog portion in response to a received Crosstalk and Mismatch, CTM, signal and the input transmission signal. The transmitter system further comprises one or more CTM modules configured to receive one or more input transmission signals. The CTM module comprises to separately generate for 10 each DI DPD module the CTM signal, where said CTM signals represent CTM distortions caused by one or more output transmission signals of each said analog portion.

Apparatus and method for identification and compensation of distortion in a multi-antenna system

It is provided an amplifier arrangement for optimizing efficiency at a peak power level and a back-off power level &#x3b3;. The amplifier arrangement comprises an input power splitter dividing an input signal into a first signal having a power Pand a second signal having a power P, a main transistor operating in a class-B like mode receiving the first signal, an auxiliary transistor operating in a class-C mode receiving the second signal. The received first and second signals have a phase offset value &#x3b8;, wherein &#x2212;&#x3c0;&#x3c;&#x3b8;&#x3c;&#x3c0;. The amplifier arrangement further comprises a combining network. Circuit element values of the combining network, the power Pand the power P, the phase offset value &#x3b8;, a bias condition of the auxiliary transistor; and a relative size Sof the auxiliary transistor, are based on a predetermined back-off power level &#x3b3;, a current scaling factor rof the auxiliary transistor, a main transistor oversizing factor r, and an auxiliary transistor oversizing factor r, where r&#x3c;1, r&#x2267;1 and r&#x2267;1. It is also provided a method for determining properties for an amplifier arrangement.

Class-B/C Doherty power amplifier

The present disclosure provides a power amplifier comprising a main amplifier and an auxiliary amplifier. The power amplifier is configured to deliver an output power P. A First Efficiency Peak (FEP) is defined as a first efficiency peak in the power ratio Pto P. Pis a maximum power output of the power amplifier and Pdefines a power ratio at the FEP. The main amplifier is configured to be biased by a main amplifier bias Vthat is substantially equal to an auxiliary amplifier bias Vtimes xwith xbeing a main amplifier output current in relation to the maximum current through the main amplifier when Pequals P. The impedances of a load and a main amplifier transmission line are arranged to be substantially equal. A corresponding method and a node in a wireless communication system comprising the power amplifier are also disclosed.

Wideband and reconfigurable Doherty based amplifier

Growing community of inventors

Mölnlycke, Sweden

Christian Fager