RF IC Calibration Architecture Using On-Chip Cross-Circuit Paths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Accurate calibration of multi-transceiver RF systems is challenging due to the need for elaborate testing equipment and environmental factors affecting RF signals, making it difficult to achieve precise phase and attenuation adjustments in assembled systems.
Innovation Solution
The implementation of on-chip switchable cross-circuit calibration paths allows for direct coupling of RF circuits to a test system, isolating other circuitry and enabling calibration at lower frequencies, thereby mitigating environmental influences and allowing for periodic self-calibration within the final system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If over-the-air calibration is performed at high frequencies, then transceiver performance can be measured, but environmental factors alter, shield, attenuate, or distort the test signals reducing measurement accuracy
Solution Approach 1:
The patent extracts the calibration measurement process from the problematic over-the-air environment by creating direct on-chip test signal paths. Test signals are routed through internal calibration paths that bypass external antennas and environmental interference, allowing measurements to be performed in a controlled on-chip environment rather than through free-space propagation susceptible to environmental factors.
Solution Approach 2:
The patent introduces on-chip calibration paths and test signal routing structures as intermediaries between the transceiver components and measurement points. These intermediary paths provide controlled signal transmission routes that eliminate the need for over-the-air testing, thereby removing environmental factors from the measurement equation while still allowing comprehensive transceiver performance characterization.
2Measurement precision
If elaborate testing equipment is used for over-the-air calibration, then high frequency RF signal measurement is possible, but the testing environment becomes complex and heavily influenced by environmental factors
Solution Approach 1:
The patent extracts the essential calibration functionality from complex external testing equipment by integrating test signal generation, routing, and measurement capabilities directly into the chip. This eliminates the need for elaborate external RF testing equipment and complex over-the-air test setups, reducing overall system complexity while maintaining measurement precision.
Solution Approach 2:
The patent merges the calibration test functions with the existing transceiver circuitry by integrating calibration paths, switches, and measurement points directly into the chip architecture. This consolidation eliminates the need for separate external testing equipment and complex test environments, achieving both measurement precision and reduced device complexity.
3Ease of manufacture
If factory calibration is performed, then initial transceiver performance can be adjusted, but the calibration does not account for usage environment factors such as temperature, noise, and component degradation
Solution Approach 1:
The patent implements preliminary factory calibration using the integrated on-chip calibration paths to establish baseline transceiver performance. The same calibration infrastructure then enables periodic in-field recalibration, allowing the system to adapt to usage environment changes while maintaining the simplicity of the calibration process that was established during manufacturing.
Solution Approach 2:
The patent enables transceivers to perform their own calibration using integrated on-chip test paths and signal routing. The calibration functionality is self-contained within the chip, allowing periodic self-calibration in the field without requiring external testing equipment or complex test environments, thus maintaining both ease of operation and adaptability to usage conditions.
Data Source
AI summary
A calibration architecture that enables accurate calibration of radio frequency (RF) integrated circuits (ICs) chips used in multi-transceiver RF systems in a relatively simple testing environment. Embodiments of the invention include one or more on-chip switchable cross-circuit calibration paths that enable direct coupling of a portion of the on-chip circuit to an RF test system while isolating other circuitry on the chip. Periodic self-calibration of an RF IC can be performed after initial factory calibration, so that adjustments in desired performance parameters can be made while such an IC is embedded within a final system, and/or to take into account component degradation due to age or other factors.