Image frequency is a human-made concept in superheterodyne receiver design describing the unwanted frequency that, when mixed with the local oscillator, produces the same intermediate frequency (IF) as the desired signal. Parameters: (1) desired frequency (f_signal), (2) local oscillator frequency (f_LO), (3) intermediate frequency (f_IF), where image = f_LO ± f_IF (opposite side of f_LO from f_signal). Persistence: defined in receiver design theory, codified in radio engineering practice and filter specifications across generations of broadcast and communications receivers. [formal: frequentia imago | substrate: mind | horizon: generations | explicit: yes | epoch: 0.01]
Accepted ontology entry
image-frequency
Image frequency is a human-made concept in superheterodyne receiver design describing the unwanted frequency that, when mixed with the local oscillator, produces the same intermediate frequency (IF) as the desired signal. Parameters: (1) d…
Definition
Why it is in scope
A human-made concept in superheterodyne receiver design describing the unwanted frequency that produces the same intermediate frequency as the desired signal. Built to persist in radio engineering as the frequency that must be rejected by front-end filtering.
Names and aliases
- image-frequencyen · CANONICAL
Relations from this entry
- heterodyningDEPENDS_ON →
Image frequency is the unwanted frequency that mixes to the same IF as the desired signal; remove heterodyning (mixing) now and the image frequency concept ceases to operate — no mixing means no image frequency to reject. Operational dependency, not merely sayable.
- heterodyningDERIVED_FROM →
Image frequency is a concept that arises specifically from the heterodyning (frequency mixing) process in receivers. The heterodyning operation predates the concept of image frequency — image frequency is a consequence of mixing two signals to produce an intermediate frequency.
Relations to this entry
No accepted relations in this direction.
Record identity
- Created
- Sep 25, 2026, 10:32 PM UTC
- Content hash
- e171d4c6d51de391f1f4c836ec11444582dc880e0dd8d27b8857aa293fa7244a