Dual band patch antenna

1. A dual band patch antenna comprising:

a first radiation conductor disposed on a first layer;

a second radiation conductor disposed on a second layer different from the first layer;

a ground pattern disposed on a third layer different from the first and second layers;

a first conductor electrically coupled to the first radiation conductor and disposed on a layer different from the first layer;

a second conductor electrically coupled to the second radiation conductor and disposed on a layer different from the second layer;

a first open stub having one end connected to the first conductor and other end opened; and

a second open stub having one end connected to the second conductor and other end opened,

wherein the first radiation conductor is larger than the second radiation conductor,

wherein the first open stub is shorter than the second open stub, and

wherein a first distance between the first and third layers is different from a second distance between the second and third layers.

2. The dual band patch antenna as claimed in claim 1 ,

wherein a length of the first open stub is about ¼ of a wavelength of a second antenna resonance signal radiated from the second radiation conductor,

wherein a length of the second open stub is about ¼ of a wavelength of a first antenna resonance signal radiated from the first radiation conductor.

3. The dual band patch antenna as claimed in claim 1 , further comprising a first excitation conductor disposed so as to overlap the first radiation conductor.

4. The dual band patch antenna as claimed in claim 1 , further comprising a second excitation conductor disposed so as to overlap the second radiation conductor.

5. The dual band patch antenna as claimed in claim 1 , further comprising:

a first excitation conductor disposed so as to overlap the first radiation conductor; and

a second excitation conductor disposed so as to overlap the second radiation conductor.

6. The dual band patch antenna as claimed in claim 3 , wherein the first excitation conductor is in a floating state.

7. The dual band patch antenna as claimed in claim 4 , wherein the second excitation conductor is in a floating state.

8. The dual band patch antenna as claimed in claim 5 , wherein the first and second excitation conductors are in a floating state.

9. The dual band patch antenna as claimed in claim 3 , wherein a third distance between the first radiation conductor and the first excitation conductor is shorter than a fourth distance between the first radiation conductor and the second radiation conductor.

10. The dual band patch antenna as claimed in claim 4 , wherein a fifth distance between the second radiation conductor and the second excitation conductor is shorter than a sixth distance between the first radiation conductor and the second radiation conductor.

11. The dual band patch antenna as claimed in claim 1 , wherein a plurality of sets of the first and second radiation conductors are arranged.

12. The dual band patch antenna as claimed in claim 11 , wherein the plurality of sets of the first and second radiation conductors are arranged in one direction.

13. The dual band patch antenna as claimed in claim 11 , wherein the plurality of sets of the first and second radiation conductors are arranged in a matrix.