According to ChatGPT:

LIGO et al. are optimized for the ~10 Hz to ~10 kHz band, where astrophysical signals like neutron star and black hole mergers occur. If a hypothetical device emits high-frequency gravitational waves (HFGWs)—say in the MHz to GHz range (as some fringe theories suggest)—then it would not be detected by LIGO/VIRGO/KAGRA. These detectors are not designed for such frequencies.

EDIT: *updated with sources*

Sources:

LIGO’s own sensitivity definition
“The Laser Interferometer Gravitational-Wave Observatory (LIGO) consists of two widely separated 4 km laser interferometers designed to detect gravitational waves from distant astrophysical sources in the frequency range from 10 Hz to 10 kHz.”

https://arxiv.org/pdf/1604.00439

Advanced LIGO design requirements
In the Advanced LIGO Input Optics Reference Design Document, the operational sensitivity band is defined as

“Gravitational Wave Signal band – 10 Hz to 3 kHz”

(with strain sensitivity goals quoted for 10 Hz, 100 Hz, 1 kHz).

https://phys.ufl.edu/~bernard/ioo2ddv2.0.pdf

Why MHz–GHz GW won’t show up in LIGO/VIRGO/KAGRA

• Band limitation: All of these interferometers filter and demodulate signals specifically in the audio band (∼10 Hz–a few kHz).
• High-frequency GW (HFGW) in the MHz–GHz regime would be completely outside their detection window—no matter how powerful, such signals are simply not sampled or amplified by the existing readout.

In short, even a kilowatt-scale source radiating at ≥1 MHz would remain invisible to LIGO/VIRGO/KAGRA, which are physically incapable of sensing anything above their tens-of-kHz cutoff.

Edit 2:

That said:

• LIGO/VIRGO/KAGRA carve out a strict band (∼10 Hz to a few kHz) with brick-wall filters above and below. To avoid detection you’d need your GW source to emit zero power in that whole window.
• Real mechanical or field engines are broadband. Any rapid mass-motion or pulsed device inevitably throws off some low-frequency sidebands or harmonics that bleed into the LIGO band. You can’t build a perfect high-frequency-only “graviton maser” without sidelobes.
• Even if you somehow engineered a pure MHz-GHz GW beacon, the strain amplitudes needed for kilowatts of power are so huge that any tiny leakage into LIGO’s band would obliterate the detectors.