arXiv subjects

Yanbo He

Publications and source records attributed to Yanbo He.

5 recordsLinked to original sources

arXiv2026

402Pilot: An x402 Decision Layer for Autonomous Agent Micropayments

Programmable-payment protocols such as x402 enable per-request micropayments, but they do not determine which payable service an autonomous agent should buy under a finite wallet. We formulate this buyer-side problem as agent-native payment decision-making: contextual provider selection under wallet pressure, chosen-only paid feedback, and changing market conditions. We propose 402Pilot, a protocol-agnostic buyer-side decision layer between autonomous agents and payment execution that implements purchasing policies for selecting among payable providers. We instantiate it with PA-DCT, a payment-aware discounted contextual Thompson-sampling policy that adapts purchasing decisions under wallet pressure while learning from post-payment feedback. To evaluate buyer-side payment policies, we introduce 402Pilot-Bench, a frozen-replay benchmark spanning 823 tasks, five heterogeneous provider pipelines, and three market regimes, each evaluated over 30 paired seeds. PA-DCT achieves the strongest fixed-wallet adaptive trade-off among non-oracle policies: it maintains competitive service quality while spending only 39 to 43 percent of the wallet and reallocates spending as market conditions change. It attains the best non-oracle PA-gap/T under the price shock and the best mean and worst-case ranks across the nine scenario-metric combinations of quality, ROI, and PA-gap/T. Comparisons with learning baselines and component ablations further support the effectiveness and design of the proposed decision policy. These results suggest that programmable payment must be complemented by buyer-side decision-making capable of learning service value and adapting purchasing decisions accordingly.

cs.AI↗

arXiv2021

A mmWave Oscillator Design Utilizing High-Q Active-Mode On-Chip MEMS Resonators for Improved Fundamental Limits of Phase Noise

(RFT) allows very high-Q active mode resonators, promising crystal-less monolithic clock generation for mmWave systems. However, there is a strong need for design of mmWave oscillators that utilize the high-Q of active-mode RFT (AM-RFT) optimally, while handling unique challenges such as resonator's low electromechanical transduction. In this brief, we develop a theory and through design and post-layout simulations in 14 nm Global Foundry process, we show the first active oscillator with AM-RFT at 30 GHz, which improves the fundamental limits of phase noise and figure-of-merit as compared to the oscillators with conventional LC resonators. For AM-RFT with Q factor of 10K, post layout simulation results show that the proposed oscillator exhibits phase noise less than -140 dBc per Hz and figure-of-merit greater than 228 dBc per Hz at 1 MHz offset for 30 GHz center frequency, which are more than 25 dB better than the existing monolithic LC oscillators.

eess.SP↗

arXiv2021

X-Band Fin Resonant Body Transistors in 14nm CMOS Technology

Here we present the first demonstration and in-depth study of unreleased acoustic resonators in 14nm FinFET technology in the IEEE X band, which offer a zero-barrier-to-entry solution for high Q, small footprint, resonant tanks integrated seamlessly in advanced CMOS nodes. These devices leverage phononic waveguides for acoustic confinement, and exploit MOS capacitors and transistors inherent to the technology to electromechanically drive and sense acoustic vibrations. Sixteen device variations are analyzed across thirty bias points to discern the impact of phononic confinement, gate length, and termination scheme on resonator properties. The limiting factor in FinFET resonator performance among design variations tested is shown to be Back End of Line (BEOL) confinement, with devices with acoustic waveguides incorporating Mx and Cx metal layers exhibiting 2.2x higher average quality factor (Q) and peak amplitude, with maximum Q increasing from 115 to 181 and maximum amplitude scaling from 0.8 to 4.5 uS. A detailed analysis of biasing in the highest performing device shows good fit with a derived model, which addresses the velocity saturated piezoresistive effect for the first time in active resonant transistors. Peak differential transconductance that is dominated by changes in the silicon band-structure, as expected from an analysis that includes contributions from the piezoresistive effect, electrostatic modulation, and silicon bandgap modulation.

physics.app-ph↗

arXiv2020

Analysis and Design Considerations for Achieving the Fundamental Limits of Phase Noise in mmWave Oscillators with On-Chip MEMS Resonator

Very small electromechanical coupling coefficient in micro-electromechanical systems (MEMS) or acoustic resonators is quite of a concern for oscillator performance, specially at mmWave frequencies. This small coefficient is the manifestation of the small ratio of motional capacitance to static capacitance in the resonators. This work provides a general solution to overcome the problem of relatively high static capacitance at mmWave frequencies and presents analysis and design techniques for achieving extremely low phase noise and a very high figure-of-merit (FoM) in an on-chip MEMS resonator based mmWave oscillator. The proposed analysis and techniques are validated with design and simulation of a 30 GHz oscillator with MEMS resonator having quality factor of 10,000 in 14 nm GF technology. Post layout simulation results show that it achieves a phase noise of -132 dBc/Hz and FoM of 217 dBc/Hz at offset of 1 MHz.

eess.SP↗

arXiv2019

A tunable ferroelectric based unreleased RF resonator

This paper introduces the first tunable ferroelectric capacitor (FeCAP) based unreleased RF MEMS resonator, integrated seamlessly in Texas Instruments' 130nm Ferroelectric RAM (FeRAM) technology. An array of FeCAPs in this complementary metal-oxide-semiconductor (CMOS) technology's back-end-of-line (BEOL) process were used to define the acoustic resonance cavity as well as the electromechanical transducers. To achieve high quality factor (Q) of the resonator, acoustic waveguiding for vertical confinement within the CMOS stack is studied and optimized. Additional design considerations are discussed to obtain lateral confinement and suppression of spurious modes. An FeCAP resonator is demonstrated with fundamental resonance at 703 MHz and Q of 1012. This gives a frequency quality factor product fQ = 7.11$\times$10$^1$$^1$ which is 1.6$\times$ higher than the most state-of-the-art Pb(Zr,Ti)O$_3$ (PZT) resonators. Due to the ferroelectric characteristics of the FeCAPs, transduction of the resonator can be switched on and off by adjusting the electric polarization. In this case, the resonance can be turned off completely at $\pm$0.3V corresponding to the coercive voltage of the constituent FeCAP transducers. These novel switchable resonators may have promising applications in on-chip timing, ad-hoc radio front ends, and chip-scale sensors.

physics.app-ph↗