LO Phase Correction for AAS RFIC Misalignment

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Phase misalignment between Radio Frequency Integrated Circuits (RFICs) in an Advanced Antenna System (AAS) due to LO generation circuitry using frequency multipliers and dividers leads to performance degradation, necessitating a method for correcting this misalignment.

Innovation Solution

A system and method that utilize a processing unit to detect and correct LO phase misalignment by obtaining near-field power measurements with test signals transmitted between RFICs, determining the appropriate LO phase state for phase alignment based on predetermined relationships between power measurements and phase states, and adjusting the phase state of each RFIC to achieve alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If frequency multipliers and dividers are used in LO generation circuitry for high frequency operation, then the system can generate desired RF and IF frequencies on the RFIC, but phase misalignment occurs between different RFICs sharing a common external LO reference

Engineering Contradiction:

Improvefrequency generation efficiencyVSAvoidphase alignment precision

Core Design Contradiction:

Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent changes the phase parameter of the LO signal by selecting between different phase states (e.g., 0 degrees or 180 degrees) of the divided LO signal. This allows correction of phase misalignment between RFICs by adjusting the phase parameter without changing the frequency generation mechanism.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary phase alignment by measuring near-field power measurements and determining the appropriate phase state before actual transmission. This preliminary adjustment ensures that phase misalignment is corrected in advance, preventing performance degradation during operation.

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If a common external LO reference is shared by multiple RFICs, then the system structure is simplified, but phase misalignment occurs due to frequency division circuitry

Engineering Contradiction:

ImproveLO distribution structureVSAvoidphase alignment reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent introduces dynamic phase state selection for each RFIC, allowing the phase to be adjusted based on measured conditions. This dynamic adaptation maintains reliability despite the simplified common reference structure, as each RFIC can independently select its optimal phase state.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements a feedback mechanism where near-field power measurements are taken and used to determine the correct phase state for each RFIC. This feedback loop ensures that phase alignment reliability is maintained by continuously monitoring and adjusting phase states based on actual system conditions.

Inventive Principle:

Principle #23Feedback

3Ease of manufacture

If frequency division is used to generate LO signals, then the LO can be obtained from a reference source, but a phase shift (e.g., 180 degrees) occurs that causes misalignment between RFICs

Engineering Contradiction:

ImproveLO signal generationVSAvoidphase alignment precision

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent inverts the phase by selecting between different phase states of the divided LO signal. When misalignment is detected, the system switches to the opposite phase state (e.g., from 0 degrees to 180 degrees), effectively correcting the phase shift introduced by the frequency division circuitry.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS12113568B2LO phase correction for AAS with multiple RFIC

Publication Date: 2024.10.08 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

Systems and methods are disclosed for correcting Local Oscillator (LO) phase misalignment between different Radio Frequency Integrated Circuits (RFIC) of an Advanced Antenna System (AAS).