1. A dual band antenna, dual band antenna comprising:
a first antenna comprising of a first ground plane having a diameter that is approximately 0.5 \u03bb1, wherein \u03bb1 represents a wavelength associated with a first frequency;
a second antenna comprising of a second ground plane having a diameter of approximately 0.5 \u03bb2, wherein \u03bb2 represents a wavelength associated with a second frequency;
wherein the first and second ground planes are arranged substantially parallel to each other at a distance H, wherein H is between approximately 0.5 \u03bb1 and approximately 0.8 \u03bb1; and
wherein the first ground plane acts as a director for the second antenna and wherein the second ground plane operates as a reflector for the first antenna.
2. The dual band antenna of claim 1 wherein the first ground plane comprises a broad band ground plane.
3. The dual band antenna of claim 1 wherein the second ground place comprises a broad band ground plane.
4. The dual band antenna of claim 1 wherein \u03bb1 represents a frequency in an S band.
5. The dual band antenna of claim 1 wherein \u03bb2 represents a frequency in a L band.
6. The dual band antenna of claim 1 wherein the first and second ground planes are affixed to a common mast.
7. The dual band antenna of claim 6 wherein the mast enables H to vary between approximately 0.5 \u03bb1 and approximately 0.8 \u03bb1, whereby a pattern of the dual band antenna is shaped by varying H.
8. The dual band antenna of claim 1 wherein cross polarization is reduced.
9. The dual band antenna of claim 1 wherein \u03bb1 represents a frequency in band higher than an S band.
10. The dual band antenna of claim 1 wherein \u03bb2 represents a frequency in a band lower than a L band.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An optical module comprising:
an optical fiber having an end which is diagonally formed in relation to the optical axis and;
a ferrule supporting the optical fiber so that the end of the optical fiber protrudes.
2. The optical module according to claim 1, wherein the optical fiber and the ferrule are jointed by an adhesive, and a core of the optical fiber is exposed at the end face of the optical fiber.
3. An optical module, wherein a ferrule supporting an optical fiber so that an end of the optical fiber protrudes and the optical fiber are jointed by an adhesive having the same refractive index as of a core of the optical fiber, and an end of the core of the optical fiber is coated with the adhesive.
4. The optical module according to claim 1, wherein a length of the optical fiber exposed from the ferrule is in the range from once to fivefold a diameter of the optical fiber.
5. The optical module according to claim 1, wherein a concave section is formed at a fiber holding section of the ferrule, in which the end of the optical fiber protrudes, and a depth of the concave section is larger than a height, a protruding amount of the end of the fiber.
6. The optical module according to claim 5, wherein a light emitting device is provided, and the height, the protruding amount of the protruding section of the optical fiber, is made higher so that an end face of the ferrule is not illuminated with emitted signal light of the light emitting device entering the optical fiber.
7. The optical module according to claim 1, wherein the ferrule consists of a first ferrule supporting at least a wire of the optical fiber and a second ferrule supporting the first ferrule and the optical fiber, the first ferrule is formed from SUS 303, and the second ferrule is formed from SUS 304.
8. The optical module according to claim 1, wherein a groove section capable of containing an adhesive is provided on a joint face inside the ferrule opposed to a coating of the optical fiber.
9. An optical transmitter-receiver using the optical module according claim 1 for optical transmitting and receiving.
10. The optical module according to claim 3, wherein a length of the optical fiber exposed from the ferrule is in the range from once to fivefold a diameter of the optical fiber.
11. The optical module according to claim 3, wherein a concave section is formed at a fiber holding section of the ferrule, in which the end of the optical fiber protrudes, and a depth of the concave section is larger than a height, a protruding amount of the end of the fiber.
12. The optical module according to claim 11, wherein a light emitting device is provided, and the height, the protruding amount of the protruding section of the optical fiber, is made higher so that an end face of the ferrule is not illuminated with emitted signal light of the light emitting device entering the optical fiber.
13. The optical module according to claim 3, wherein the ferrule consists of a first ferrule supporting at least a wire of the optical fiber and a second ferrule supporting the first ferrule and the optical fiber, the first ferrule is formed from SUS 303, and the second ferrule is formed from SUS 304.
14. The optical module according to claim 3, wherein a groove section capable of containing an adhesive is provided on a joint face inside the ferrule opposed to a coating of the optical fiber.
15. An optical transmitter-receiver using the optical module according to claim 3 for optical transmitting and receiving.