lu6etj wrote in
:
Could it simply be a capacitive coupling method without any matching
property ?

That depends what you mean by "without any matching property".

If the o/c stub is less than an electrical quarter wave (as it seems from
the description, it must introduce some series capacitive reactance, and
loss resistance, the longer it is, the higher the loss resistance.

It is not at all obvious why they would do what you described (and for
Tom's benefit, I am not talking about a gamma match).

Owen