Double omni-directional antenna
AssigneeSiemens Aktiengesellschaft
InventorsAnton Brunner, Nikolaus Willburger
Life of this patent
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Abstract
A double omni-directional antenna for use with a transponder is disclosed allowing simultaneous operation within two different frequency bands. A double coaxial line is provided having outer, central, and inner concentric conductors. The outer and central conductors form a coaxial feed for a lower frequency antenna and the central and inner connectors form a coaxial feed for a high frequency antenna. The higher frequency antenna is located directly above the lower frequency antenna and each is either a unipole for vertically polarized radiation or a slot radiator for horizontally polarized radiation.
Claims23
A double omni-directional antenna for electromagnetic waves falling within two different frequency bands comprising a double coaxial line including an inner, a central and an outer conductor which in a vertical position comprise with respect to the lower of said frequency bands a lower coaxial line section as a low frequency omni-directional radiator formed by said central and said outer conductors, said central conductor being the inner conductor of said lower coaxial line section and said outer conductor being the outer conductor of said lower coaxial line section, and which for the higher of said frequency bands comprise an upper coaxial line section above said lower coaxial line section as a high frequency omni-directional radiator formed by said inner and said central conductors, said inner conductor being the inner conductor of said upper coaxial line section and said central conductor being the outer conductor of said upper coaxial line section.
A double omni-directional antenna for electromagnetic waves falling within two different frequency bands comprising:
- a. a double coaxial line having an inner, a central and an outer conductor forming inner and external coaxial lines;
- b. a coaxial line section effective as a lower frequency band omni-directional radiator and formed by a continuation of said central and said outer conductors, said central conductor forming an inner conductor of said radiator and said outer conductor forming an outer conductor of said radiator;
- and
- c. a coaxial line section effective as a higher frequency band omni-directional radiator located above the center portion of said lower frequency band radiator and formed by a continuation of said inner and said central conductors, said inner conductor forming an inner conductor of said radiator and said central conductor forming an outer conductor of said radiator.
A double omni-directional antenna for electromagnetic waves falling within two different frequency bands comprising a double coaxial line including an inner, a central and an outer conductor which in a vertical position exhibit with respect to the lower of said frequency bands a lower coaxial line section effective as a radiator formed by said central and said outer conductors, said central conductor being the inner conductor of said lower coaxial line section and said outer conductor being the outer conductor of said lower coaxial line section, and which for the higher of said frequency bands exhibits an upper coaxial line section effective as a radiator formed by said inner and said central conductors, said inner conductor being the inner conductor of said upper coaxial line section, said central conductor being the outer conductor of said upper coaxial line section, the outer conductor of said upper coaxial line section being provided with an axial slot having a length corresponding to approximately half of the wave length of the electromagnetic waves with which said upper coaxial line section is intended to operate and in which a short circuiting pin is provided between the outer conductor and the inner conductor of said upper coaxial line section, said pin being located substantially at the center of said slot and at the edge of said slot.
A double omni-directional antenna for electromagnetic waves falling within two different frequency bands comprising a double coaxial line including an inner, a central and an outer conductor which in a vertical position exhibit with respect to the lower of said frequency bands a lower coaxial line section effective as a radiator formed by said central and said outer conductors, said central conductor being the inner conductor of said lower coaxial line section and said outer conductor being the outer conductor of said lower coaxial line section, and which for the higher of said frequency band exhibits an upper coaxial line section effective as a radiator formed by said inner and said central conductors, said inner conductor being the inner conductor of said upper coaxial line section, said central conductor being the outer conductor of said upper coaxial line section, the outer conductor of said upper coaxial line section being provided with an axial slot having a length corresponding to approximately half of the wave length of the electromagnetic waves with which said upper coaxial line section is intended to operate and in which said outer conductor of said upper coaxial line section has a second slot circumferentially offset through approximately 180.degree. with respect to said first slot.
A double omni-directional antenna for electromagnetic waves falling within two different frequency bands comprising:
- a. a double coaxial line having an inner, a central and an outer conductor forming inner and external coaxial lines;
- b. a coaxial line section effective as a lower frequency band unipole and formed by a continuation of said central and said outer conductors, said central conductor forming an inner conductor of said unipole and said outer conductor forming an outer conductor of said unipole;
- and
- c. a coaxial line section effective as a higher frequency band slot radiator located above the center portion of said lower frequency band unipole and formed by a continuation of said inner and said central conductors, said inner conductor forming an inner conductor of said slot radiator and said central conductor forming an outer conductor of said slot radiator.
A double omni-directional antenna for electromagnetic waves falling within two different frequency bands comprising:
- a. a double coaxial line having an inner, a central and an outer conductor forming inner and external coaxial lines;
- b. a coaxial line section effective as a lower frequency band radiator and formed by a continuation of said central and said outer conductors, said central conductor forming an inner conductor of said radiator and said outer conductor forming an outer conductor of said radiator;
- and
- c. a coaxial line section effective as a higher frequency band radiator located above the center portion of said lower frequency band radiator and formed by a continuation of said inner and said central conductors, said inner conductor forming an inner conductor of said radiator and said central conductor forming an outer conductor of said radiator;
- wherein at least one of said radiators is a slot radiator.
A double omni-directional antenna for electromagnetic waves falling within two different frequency bands comprising:
- a. a double coaxial line having an inner, a central and an outer conductor forming inner and external coaxial lines;
- b. a coaxial line section effective as a lower frequency band rod radiator and formed by a continuation of said central and said outer conductors, said central conductor forming an inner conductor of said rod radiator and said outer conductor forming an outer conductor of said rod radiator;
- and
- c. a coaxial line section effective as a higher frequency band rod radiator located above the center portion of said lower frequency band rod radiator and formed by a continuation of said inner and said central conductors, said inner conductor forming an inner conductor of said rod radiator and said central conductor forming an outer conductor of said rod radiator.
Dependencies are inferred from the claim text.