Antenna device

1. An antenna device, comprising:

a base having an internal thread for an external thread;

a first antenna element;

a first circuit board which is arranged on the base, electrically connected to the first antenna element, and amplifies a signal output from the first antenna element;

a shielding case arranged on the first circuit board, the shielding case having a top board;

a second antenna element arranged on the top board of the shielding case; and

a second circuit board which is electrically connected to the second antenna element and amplifies a signal output from the second antenna element,

wherein

the shielding case covers the second circuit board,

the first circuit board includes a first fixation section for the external thread,

the shielding case includes a second fixation section for the external thread, and

the first circuit board and the shielding case are fixed to the base by the first fixation section and the second fixation section being screwed together due to the external thread being screwed into the internal thread.

2. The antenna device as claimed in claim 1 , further comprising a top cover which covers the base, the first circuit board, the shielding case and the second antenna element, the top cover including a first antenna element connecting section where the first antenna element is to be connected.

3. The antenna device as claimed in claim 2 , wherein the top cover comprises

a first cable which electrically connects the first antenna element and the first circuit board, and

a third fixation section which guides and fixes the first cable to an inner wall of the top cover.

4. The antenna device as claimed in claim 3 , wherein

the first circuit board includes a connecting terminal, and

the first cable is connected to the connecting terminal by soldering.

5. The antenna device as claimed in claim 1 , wherein the base comprises

a fourth fixation section which fixes the antenna device to a fixation opening in a setting surface of a vehicle, and

a first hole for pulling a second cable and a third cable into the vehicle, one end of the second cable being electrically connected to the first circuit board and one end of the third cable being electrically connected to the second circuit board.

6. The antenna device as claimed in claim 5 , wherein

the base comprises a shielding section which includes the internal thread and which covers the first circuit board,

the shielding case comprises a second hole from which the second cable is pulled out, and

the shielding section comprises a third hole to which the second cable is pulled in.

7. The antenna device as claimed in claim 1 , wherein

the base comprises a shielding section which includes the internal thread and which covers the first circuit board.

8. The antenna device as claimed in claim 1 , wherein

the top board of the shielding case has an inclination so that an axis perpendicular to a receiving surface of the second antenna element points a zenith direction when the antenna device is set.