Self-Calibration Circuit for RF Transceivers Using Internal Receive Section
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The calibration and testing of RF circuitry in modern communications systems require expensive and time-consuming external equipment, limiting production flow and increasing costs due to the need for interactive testing and extensive external connections.
Innovation Solution
A self-calibration circuit using a built-in self-test (BIST) circuit on the same chip as the RF device, which calibrates the receive section in a receive test mode and then uses the calibrated receive section to measure and calibrate the transmit section in a transmit test mode, eliminating the need for external test equipment and reducing production delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If external test equipment is used for RF circuit calibration, then measurement precision is achieved, but device complexity and cost increase
Solution Approach 1:
The RF device performs self-calibration using its own internal components. The calibrated receive section serves as the measurement instrument to test the transmit section, eliminating the need for external test equipment. This self-service approach reduces system complexity while maintaining calibration precision through internal reference signals and measurement paths.
2Measurement precision
If interactive testing mode is used, then measurement precision is maintained, but productivity decreases
Solution Approach 1:
The BIST circuit autonomously executes calibration sequences without requiring external tester control. The calibrated receive section automatically measures transmit section performance and generates calibration data, enabling rapid sequential testing that improves productivity while maintaining precision through structured test algorithms.
Solution Approach 2:
The receive section is calibrated first in advance, creating a ready-to-use measurement instrument. This preliminary calibration enables subsequent rapid testing of the transmit section without repeating the calibration process, thereby increasing production speed while preserving measurement accuracy.
3Ease of operation
If external connection pins are added for testing, then ease of operation is improved, but area of moving object increases
Solution Approach 1:
The device uses its own internal receive section as the measurement instrument, eliminating the need for additional external connection pins. The existing RF components serve dual purposes: receive functionality and measurement capability, thereby maintaining ease of operation without increasing chip area.
Solution Approach 2:
The receive section serves multiple functions: normal receive operation and measurement of transmit section output. This multi-functionality eliminates the need for separate test pins and external equipment connections, maintaining operational ease while preserving compact chip design.
Data Source
AI summary
A self-calibration circuit and associated method for testing an RF device includes the RF device to be tested having transmit and receive sections, and a built-in self test (BIST) circuit coupled to the transmit and receive sections of the RF device on the same chip. The self-calibration circuit is configured to calibrate the receive section of the RF device in a receive test mode, and calibrate the transmit section of the RF device in a subsequent transmit test mode using the calibrated receive section to measure a transmit output signal from the transmit section and to provide calibration data therefrom used in the transmit section calibration. The self-calibration circuit may include a duplex filter coupled between the transmit and receive sections and the BIST circuit, and a multiplexor coupled between the RF device, and the BIST circuit, configured to select one or more of a plurality of RF devices to be tested.