Isolator and communication system

An isolator comprising:

• a first signal line disposed between an input side circuit and an output side circuit;
• a second signal line disposed between the input side circuit and the output side circuit and constituting a differential pair with the first signal line;
• a first capacitive element arranged on the first signal line, the first capacitive element having one end electrically connected to the input side circuit and having another end electrically connected to the output side circuit;
• a second capacitive element arranged on the second signal line, the second capacitive element having one end electrically connected to the input side circuit and having another end electrically connected to the output side circuit;
• a first inductive element having one end electrically connected to a first node between the first capacitive element in the first signal line and the output side circuit;
• and
• a second inductive element having one end electrically connected to a second node between the second capacitive element in the second signal line and the output side circuit,
• wherein the first capacitive element is disposed above a substrate,
• the first inductive element is disposed between the substrate and the first capacitive element, the first inductive element having a stacked structure,
• the second capacitive element is disposed above the substrate, and
• the second inductive element is disposed between the substrate and the second capacitive element, the second inductive element having a stacked structure,
• the isolator further comprising a ground pattern disposed on the substrate,
• wherein the first inductive element has
• a first coil pattern disposed between the ground pattern and the first capacitive element, and
• a third coil pattern disposed between the ground pattern and the first coil pattern the second inductive element has
• a second coil pattern disposed between the ground pattern and the second capacitive element, and
• a fourth coil pattern disposed between the ground pattern and the second coil pattern.