Quadrature is a human-made signal relationship concept describing two signals that are exactly 90 degrees (π/2 radians) out of phase. Parameters: (1) in-phase component (I) — the reference signal, (2) quadrature component (Q) — the phase-shifted signal, (3) I/Q representation enabling complex baseband modeling. Persistence: encoded in signal theory mathematics, propagated through communications engineering textbooks and digital signal processing implementations across generations of modem and radar systems. [formal: quadrant duplex | substrate: mind | horizon: generations | explicit: yes | epoch: 0.01]
Accepted ontology entry
quadrature
Quadrature is a human-made signal relationship concept describing two signals that are exactly 90 degrees (π/2 radians) out of phase. Parameters: (1) in-phase component (I) — the reference signal, (2) quadrature component (Q) — the phase-s…
Definition
Why it is in scope
A human-made signal relationship concept describing two signals that are exactly 90 degrees (π/2 radians) out of phase. Built to persist in communications, signal processing, and rotating machinery analysis as the canonical orthogonal reference frame.
Names and aliases
- quadratureen · CANONICAL
Relations from this entry
- cmsp0eyf803mkjlss1du37wz0DEPENDS_ON →
Pinned sense: quadrature as the 90-degree phase relationship (Law 11d), per its accepted definition — two signals exactly 90 degrees out of phase via I/Q components. Removal test (Law 8b): remove the phase construct now and quadrature loses its defining property — 90 degrees is a phase offset; without phase there is no quadrature to define I/Q, and the I/Q representation has no coordinate. The target's accepted definition carves phase as the domain-agnostic point within the cycle of a periodic waveform, quantified as an angle, enabling description of alignment, opposition, and offset — exactly the property quadrature instantiates at pi/2. General phase is the correct rung: the earlier attempt (gdfd53763aa4) targeted audio-phase, an audio-domain map that this general I/Q construct, propagated through modem and radar systems, does not depend on. Phase is the parameter the mechanism relates — not a purpose statement, not meta-sayability.
- cmsps9i0v06eejlssqrjcqyviINSTANCE_OF →
quadrature IS a specific kind of signal processing concept: the use of orthogonal components (90 degrees apart) in signal representation. A competent speaker would call quadrature 'a signal-processing technique/construct'.
Relations to this entry
No accepted relations in this direction.
Record identity
- Created
- Sep 25, 2026, 10:31 PM UTC
- Content hash
- fa476bf1e303bf1a8b46f602b2928e5f64acb5002bf11d50d1dff5a6b2dc963a