Abstract: Matching circuit for radio antenna that functions on a two-frequency band which are spaced approximately at a distance of one octave, wherein the upper band is broad. For instance, the first frequency band may be 890-940 MHz and the other band 1710-2200 MHz. The radiator may be a dipole or a monopole over the earth plane, whose bandwidth is sufficient for the first band. The larger bandwidth for the second band is obtained with a transmission circuit that moves and forms the frequency curve stepwise in the Smith chart. When necessary, the matching circuit includes a broadband Balun transformer in addition to said matching circuit.

Abstract: The present invention relates to an antenna coupling device (14) for coupling radio frequency signal from a communication device (10) having an internal first antenna, the communication device (10) operable in n frequency bands, where n>1 and n is an integer. The antenna coupling device (14) comprises a port (16) connected/connectable to a transmission line (18). A conducting surface of said antenna coupling device (14) has a geometric shape in the form of a tree structure (20) connected to said port (16).

Abstract: Matching circuit for radio antenna that functions on a two-frequency band which are spaced approximately at a distance of one octave, wherein the upper band is broad. For instance, the first frequency band may be 890-940 MHz and the other band 1710-2200 MHz. The radiator may be a dipole or a monopole over the earth plane, whose bandwidth is sufficient for the first band. The larger bandwidth for the second band is obtained with a transmission circuit that moves and forms the frequency curve stepwise in the Smith chart. When necessary, the matching circuit includes a broadband Balun transformer in addition to said matching circuit.

Abstract: An adapter antenna (2) is used for contactless connection of a mobile telephone (1) to an external antenna (4) in case the telephone lacks a connector for coaxial cable (3) for such a purpose. The most common application is when a mobile telephone is to be used in a vehicle. Transfer of radio waves occurs in the near field of the built-in antenna (6) of the telephone by capacitive coupling. One preferred embodiment especially suited for plane inverted antennae of type L, E or F is described. An optimizing method for two frequency bands is described.

Abstract: The present invention relates to an antenna coupling device (14) for coupling radio frequency signal from a communication device (10) having an internal first antenna, the communication device (10) operable in n frequency bands, where n>1 and n is an integer. The antenna coupling device (14) comprises a port (16) connected/connectable to a transmission line (18). A conducting surface of said antenna coupling device (14) has a geometric shape in the form of a tree structure (20) connected to said port (16).

Abstract: An adapter antenna (2) is used for contactless connection of a mobile telephone (1) to an external antenna (4) in case the telephone lacks a connector for coaxial cable (3) for such a purpose. The most common application is when a mobile telephone is to be used in a vehicle. Transfer of radio waves occurs in the near field of the built-in antenna (6) of the telephone by capacitive coupling. One preferred embodiment especially suited for plane inverted antennae of type L, E or F is described. An optimizing method for two frequency bands is described.