The design point: Mutual coupling occurs when the field and current from one antenna induce voltage and current in another, changing impedance, pattern, isolation, and received or transmitted power.
Why the complete system matters
Separation in wavelengths, orientation, polarization, frequency, terminations, height, and nearby structures all influence coupling. An unused but connected antenna can still reradiate.
The assumption that breaks it
Spacing antennas by a convenient number of feet without considering wavelength and pattern can create detuning or receiver overload.
Build or deploy it correctly
Model or measure S-parameters and feed-point impedance with every antenna installed and terminated normally, increase or reorient spacing, filter where needed, and verify receiver protection.
Configuration boundary
Use the exact product guide, electrical topology, geometry, materials, loading, feed, return path, support, and environment. Mechanical fit or a visually similar arrangement does not establish electrical equivalence.
