BPF-Based Thermal Sensor Circuit for On-Chip Testing of RF Circuits

Area of Science:

• Electrical Engineering
• Integrated Circuit Design
• Sensor Technology

Background:

• Radio-frequency analog integrated circuits (RF-ICs) require precise testing for performance and reliability.
• Existing RF-IC testing methods can be complex and costly.
• Monitoring figures of merit in real-time is crucial for quality control and variability assessment.

Purpose of the Study:

• To introduce and experimentally validate a new sensor topology for extracting figures of merit of RF-ICs.
• To demonstrate a cost-effective and high-performance solution for RF-IC testing and monitoring.
• To assess the sensor's capability in monitoring parameters like output power and central frequency.

Main Methods:

• Implementation of the sensor topology in a standard 0.35 μm complementary metal-oxide-semiconductor (CMOS) technology.
• Integration of a metal-oxide-semiconductor (MOS) transistor as a temperature transducer near the monitored circuit.
• Utilization of an active band-pass filter amplifier and MOS dissipating devices for characterization and validation.
• Application of the heterodyne technique with two nearby tones to a tuned radio-frequency power amplifier (420 MHz).

Main Results:

• The sensor topology was successfully implemented and validated in CMOS technology.
• Characterization of the temperature sensor's performance and limitations using MOS dissipating devices.
• Successful monitoring of the power amplifier's output power and central frequency using the sensor output voltage and a low-cost AC voltmeter.
• Demonstration of high linearity and sensitivity in the proposed sensor topology.

Conclusions:

• The developed sensor topology offers a low-cost, highly linear, and sensitive approach for RF-IC testing.
• This method enables effective monitoring of key RF-IC parameters and variability.
• The validated sensor topology presents a practical solution for enhancing RF-IC quality assurance.