What does this tell us?
Well, LDS antennas are more compact, yet fragile, while the slightly thicker and sturdier IMA enable the creation of waterproof devices. For example, the Galaxy Note 3 comes with an LDS antenna on board, while the Galaxy S4 Active houses an IMA one.
What's more, a Chinese manufacturer, Daesan Electronics, has allegedly succeeded in developing an IMA antenna that is as thick as an LDS one. Dubbed H-IMA (high performance in-mold antenna), its overall thickness is between 0.15 and 0.2mm. Rumor has it that Samsung might use Daesan's enhanced IMA antenna in some variants of the Galaxy S5.
source: ETNews via SamMobile