DOI: 10.1109/TMTT.2026.3725641   IEEEXplore: https://ieeexplore.ieee.org/document/11672205    

Low-phase noise MMIC oscillator with a high-Q glass-embedded resonator in InGaP/GaAs heterojunction bipolar transistor (HBT) technology.

4.956 GHz

This is the first known integration of 3-D glass-embedded resonators with an MMIC. Photo-sensitive glass (PSG) substrates are attractive solutions for low-loss chip structures for low volume high-Q RF components and heterogeneous integration, with low dielectric loss, low surface roughness and adjustable coefficient of thermal expansion comparable to silicon. This is also the first known demonstration of an integrated circuit oscillator locked to a chip-scale atomic beam clocks (CSABC).

Chip-scale atomic beam clocks for highly stable timekeeping in volume-constrained, battery-operated environments.

107 peak Qu at 8.8 GHz for the glass-embedded LC resonator, 52 Qu at 7.1 GHz, depending on measurement and boundary conditions; −58 dBc/Hz minimum oscillator free-running phase noise of at an offset of 1 kHz from half of a hyperfine transition frequency of 133Cs at the operational bias point; as low as −140 dBc/Hz at a 1-MHz offset when biased at a different operating point; +13 dBm peak output power ; 2 MHz/V tuning gain near the operating frequency; 3.3 ×10−10/(τ)1/2 σy average overlapping Allan deviation from the beam clock, white-noise limited from 1 to 100 s.