FMään

FM×N is a compact notation used in different technical fields, and there is no single universal definition. Its meaning is largely contextual, combining an element labeled FM with a parameter or index N.

In electronics and communications, FM most often stands for frequency modulation. Here, ×N commonly indicates a frequency multiplier with an integer factor N. A multiplier stage increases the carrier frequency by N, producing an output f_out ≈ N f_in. The modulation component can be preserved in the process, so the instantaneous frequency deviation scales with N as Δf_out ≈ N Δf_in. This usage appears in RF design and frequency synthesis when a stable reference must generate higher carrier frequencies.

In mathematics and computer science, FM can denote functions, modules, or functors, and × N signals a product with the set or object N. For example, FM × N might denote a Cartesian or external product forming a larger structure from a base object FM and the index or set N. This interpretation follows common uses of cross or direct product notation in algebra and category theory.

In some DSP or music-technology contexts, FM×N may be encountered as shorthand for combining frequency modulation with an N-fold aspect, such as N-voice polyphony or layered modulation schemes. However, this usage is not standardized and can vary between authors or disciplines.

Because FM×N spans multiple domains, accurate interpretation depends on the field and the surrounding notation. When encountering FM×N, it is best to consult domain-specific definitions or the source material for a precise meaning.