Hybrid antenna unit

A hybrid antenna unit comprising:

• a circuit board having top and bottom surfaces opposite to each other;
• a planer antenna element mounted on the top surface of said circuit board and receiving first and second radio waves from first and second kinds of artificial satellites;
• an antenna base and a top cover that cover said circuit board and said planer antenna element, said antenna base facing the bottom surface of said circuit board, said top cover facing the top surface of said circuit board;
• a bar antenna element standing on said top cover in a slanting position;
• a processing unit mounted on the bottom surface of said circuit board and connected to said planer antenna element, said processing unit processing the first and the second radio waves;
• a shielding case mounted on the bottom surface of said circuit board and shielding said processing unit;
• and
• a booster circuit mounted on said circuit board and being for use in said bar antenna element,
• wherein said planer antenna element comprises:
• a dielectric board having a top surface and a bottom surface which are opposed to each other, said dielectric board having a board through hole which penetrates from the top surface and the bottom surface at a feeding point;
• a ring-shaped first antenna radiation electrode made of a conductive film, said first antenna radiation electrode being formed on the top surface of the dielectric board at an outer region thereof;
• a second antenna radiation electrode made of a conductive film, said second antenna radiation electrode being formed on the top surface of said dielectric board at a central portion thereof so as to be enclosed by said first antenna radiation electrode and to be apart from said first antenna radiation electrode;
• a ring-shaped non-feeding electrode made of a conductive film, said non-feeding electrode being formed on the top surface of said dielectric board so as to be sandwiched between said first antenna radiation electrode and said second antenna radiation electrode and to be apart therefrom;
• a ground electrode made of a conductive firm, said ground electrode being formed on the bottom surface of said dielectric board, said ground electrode having a ground through hole which is substantially concentric with the board through hole and which has a diameter larger than that of the board through hole;
• a feeding pattern formed on the top surface of said dielectric board, said feeding pattern feeding to said first antenna radiation electrode by electromagnetic coupling;
• and
• a feeding pin having a first end connected to said second antenna radiation electrode at the feeding point, said feeding pin having a second end which is guided to the bottom surface side of said dielectric board via the board through hole and the ground through hole,
• wherein a combination of said first antenna radiation electrode, said ground electrode, and said feeding pattern serves as a first antenna portion for receiving the first radio wave, and a combination of said second antenna radiation electrode, said ground electrode, and said feeding pin serves as a second antenna portion for receiving the second radio wave.