A 24-31GHz Compact Low-Power Complex Impedance Sensor for Beamforming Transmitters in 22nm FD-SOI
We present a complex impedance sensor to measure the impedance variations at the output of a (phased-array) transmitter (TX) operating around 28 GHz. 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 24 GHz to 31 GHz and an input power dynamic range of 7 dB, this circuit can sense reflection coefficients up to 0.74 with a maximum magnitude error of 0.14 and a maximum phase error of 12.8°. It consumes 8 mW of power and occupies only $0.0043 \mathrm{~mm}^{2}$.
Authors
- Rana ElKashlan (ORCID: https://orcid.org/0000-0003-0576-4344)
- Xuepu Wu (ORCID: https://orcid.org/0000-0001-7285-6893)
- Piet Wambacq (ORCID: https://orcid.org/0000-0003-4388-7257)
- Dries Peumans (ORCID: https://orcid.org/0000-0001-6474-6846)
- Giovanni Mangraviti (ORCID: https://orcid.org/0000-0001-5134-7205)
- Yang Zhang (ORCID: https://orcid.org/0000-0002-0544-1476)
Institutions
- Vrije Universiteit Brussel (BE)
- IMEC (BE)
Publication Details
- Published
- 2025-06-15
- DOI
- https://doi.org/10.1109/rfic61188.2025.11082817
- Primary Topic
- Radio Frequency Integrated Circuit Design
- Type
- article
- Field-Weighted Citation Impact
- 0.00