Recently, the research team led by Ye Dawei from our institution made a notable contribution to the field of solid-state circuits by publishing a research paper titled 'Analysis and Design of Series-Resonant Voltage-Controlled Oscillators Using Magneto-Mutual Resistance Technique' in the IEEE Journal of Solid-State Circuits (JSSC), a premier international journal in this domain. This milestone was initially unveiled at the 2025 IEEE VLSI Technology Symposium, where it captured significant interest from both the academic and industrial sectors. Following this, the team received an invitation to submit a comprehensive paper to a special edition of JSSC, elaborating on the core theory, design methodology, and experimental validation. The paper has now been successfully accepted for publication. This accomplishment represents the first instance where work from our institution has been concurrently published in both VLSI and JSSC.

The spectral purity of frequency generation within the millimeter-wave band presents a formidable technical hurdle for 5G and future communication systems. To tackle the challenge of achieving a balance between low phase noise, low power consumption, and a compact footprint in millimeter-wave voltage-controlled oscillators (VCOs), the paper introduces an innovative series-resonant VCO (SR-VCO) architecture leveraging the magneto-mutual resistance (MMR) technique. This architecture exploits the coupling between the primary and secondary sides of a single transformer, generating two equivalent resistances (i.e., MMR) within the resonant tank by manipulating a 90° phase shift between currents. These resistances, produced through magnetic coupling, substantially boost the resonant tank's equivalent impedance, thereby diminishing core current and power consumption without introducing thermal noise or compromising the quality factor (Q), as physical resistors would.

The SR-VCO, designed based on this principle, offers several advantages, including reduced power consumption, low phase noise, and high integration. In terms of power efficiency, MMR enhances the resonant tank's impedance, significantly slashing core power consumption by roughly an order of magnitude compared to traditional series-resonant oscillators, all while maintaining the Q value. Regarding low phase noise, the paper delves into an in-depth analysis of the impact of magneto-mutual resistance on the impulse sensitivity function (ISF). By diminishing the ISF amplitude, MMR effectively curbs active device noise, achieving exceptionally low phase noise performance. At 27.78 GHz, it attains -120.09 dBc/Hz (@1 MHz offset), reaching international leading standards.

In terms of high integration, owing to the utilization of merely one transformer, this structure markedly reduces the area compared to other multi-core oscillators (only 0.06 mm²), while achieving comparable or even superior phase noise performance. The first author of the paper is Chen Luyang, a first-year doctoral student, and the corresponding author is Researcher Ye Dawei.