6G • RAN
True Time Delay (TTD)
Photonic & Analog True Time Delay Lines
Physical delay lines that introduce frequency-independent time offsets rather than phase shifts, delivering broadband beamforming without beam dispersion.
Technical Explanation
Phase shifters introduce a constant phase shift (e.g., 90 degrees), which corresponds to different time delays at different frequencies, causing wideband beam dispersion. True Time Delay (TTD) hardware introduces an exact time delay (in picoseconds) using switched transmission lines or photonic optical delay waveguides. TTD preserves pristine pulse shapes and beam alignment across extreme multi-gigahertz Sub-THz waveforms.
Key Functions
- Frequency-independent picosecond-scale time delay generation across antenna elements
- Silicon photonics and switched delay line implementations with low insertion loss
- Broadband beamforming maintaining ultra-short pulse integrity in THz radar and communications
- Eliminating beam squint and dispersion in extreme ultra-wideband transceivers
- Essential hardware technology for gigahertz-wide ISAC radar pulse transmission
Specifications
IEEE Journal of Lightwave Technology, 6G Hardware Consortium
Interfaces
TTD-PhotonicPicosecond-Delay-Line
Related 6G Concepts
Want to memorize 6G concepts like this one?
Study it with SuperMemo SM-2 spaced repetition flashcards.