In the datasheet of the BGM113 Bluetooth module, there are layout guidelines.
Clear recommandations are made for metallic objects (clearance of 10 mm), but regarding the plastic objects it is only said :
"Do not place plastic or any other dielectric material in closs proximity to the antenna."
I intend to use the BGM113 on a small PCB and I need to produce a plastic case around it that would not impact on the antenna efficiency.
Are there quantitative recommandations regarding plastic objects close to the antenna?
Please keep the gap as big as possible between antenna and plastic case. It recommends to leave the gap over 3-5 mm.