We present a complex impedance sensor to measure the impedance variations at the output of a (phased-array) transmitter (TX) operating around 28GHz. Based on complex voltage sensing of the output balun in a transmitter, the envelope detectors and injection-locked ring oscillators (ILRO) split the amplitude and phase sensing of voltages for computing the complex impedance. With a bandwidth spanning from 24GHz to 31GHz and an input power dynamic range of 7dB, this circuit can sense reflection coefficients up to 0.74 with a maximum magnitude error of 0.14 and a maximum phase error of 12.8â—¦. It consumes 8mW of power and occupies only 0.0043mm2.
Wu, X, Zhang, Y, Mangraviti, G, ElKashlan, R, Peumans, D & Wambacq, P 2025, A 24-31GHz Compact Low-Power Complex Impedance Sensor for Beamforming Transmitters in 22nm FD-SOI. in 2025 IEEE Radio Frequency Integrated Circuits Symposium (RFIC). Digest of papers - IEEE Radio Frequency Integrated Circuits Symposium, pp. 1-4. https://doi.org/10.1109/RFIC61188.2025.11082817
Wu, X., Zhang, Y., Mangraviti, G., ElKashlan, R., Peumans, D., & Wambacq, P. (2025). A 24-31GHz Compact Low-Power Complex Impedance Sensor for Beamforming Transmitters in 22nm FD-SOI. In 2025 IEEE Radio Frequency Integrated Circuits Symposium (RFIC) (pp. 1-4). (Digest of papers - IEEE Radio Frequency Integrated Circuits Symposium). https://doi.org/10.1109/RFIC61188.2025.11082817
@inproceedings{0bfee044a48748219e45f874379b7f2f,
title = "A 24-31GHz Compact Low-Power Complex Impedance Sensor for Beamforming Transmitters in 22nm FD-SOI",
abstract = "We present a complex impedance sensor to measure the impedance variations at the output of a (phased-array) transmitter (TX) operating around 28GHz. Based on complex voltage sensing of the output balun in a transmitter, the envelope detectors and injection-locked ring oscillators (ILRO) split the amplitude and phase sensing of voltages for computing the complex impedance. With a bandwidth spanning from 24GHz to 31GHz and an input power dynamic range of 7dB, this circuit can sense reflection coefficients up to 0.74 with a maximum magnitude error of 0.14 and a maximum phase error of 12.8â—¦. It consumes 8mW of power and occupies only 0.0043mm2.",
author = "Xuepu Wu and Yang Zhang and Giovanni Mangraviti and Rana ElKashlan and Dries Peumans and Piet Wambacq",
year = "2025",
doi = "10.1109/RFIC61188.2025.11082817",
language = "English",
isbn = "9798331514129",
series = "Digest of papers - IEEE Radio Frequency Integrated Circuits Symposium",
publisher = "IEEE",
pages = "1--4",
booktitle = "2025 IEEE Radio Frequency Integrated Circuits Symposium (RFIC)",
}