Mitsubishi Denki Kabushiki Kaisha

Eiichi Kuroda

Minori Kawano

Yasuhiro Ishizaki

Fumiaki Komatsu

Kohji Ogawa

Sadayuki Tsukagoshi

Hiroyuki Kuroiwa

Masato Sato

A radio relay system including a water-proof conductor housing on which is located a pair of antennas, one antenna being used for transmitting and receiving radio carrier wave signals of a first and a second frequency, respectively, while the other antenna is used for transmitting and receiving radio carrier wave signals of a third and a fourth frequency, respectively. A skirt for each of the antennas is located adjacent the antennas on the housing, one skirt has a length equal to a quarter of the wavelength of the first frequency while the other skirt has a length equal to a quarter wavelength of the third frequency. A relay circuit is located in the housing which includes circuitry for extracting and combining a portion of the radio carrier wave signals of the first and the third frequencies respectively radiated from the two antennas with the radio carrier wave signals of the first and third frequencies respectively received by the opposite antenna of the pair of antennas for cancelling unwanted local interference therebetween.

Radio relay system, including interference signal cancellation

A radio relay system which comprising an external conductor, a first antenna installed on the externals conductor for transmitting and receiving a first radio carrier wave, a second antenna installed on the external conductor for transmitting and receiving a second radio carrier wave, a skirt provided around the second antenna, the skirt having a length equal to a quarter of the wavelength of the second radio carrier signal, and a relay device which includes a branching filter for extracting a part of the second radio carrier wave as a carrier wave, an adjusting unit for adjusting the amplitude and phase of the carrier wave extracted by the branching filter, and a combining unit for combining the carrier wave extracted by the branching filter with the second radio carrier wave received through the first antenna, and the relay device transmitting as the second radio carrier through the second antenna the first radio carrier wave received through the first antenna.

Radio relay system with a multiplex separation circuit and control for

A base station for a mobile communications system including an antenna for transmitting a radio carrier wave to a mobile communications device and receiving signals therefrom, a coaxial external conductor including a skirt in the form of a sun shade having a length equal to a quarter wavelength of the radio carrier wave, a radio section located inside the coaxial external conductor for providing radio communication with the mobile communication device via the antenna, and a connecting section connecting the radio section to a telephone line and where the antenna is configured in the form of an upper disk of a discone antenna and where the skirt is a lower conical member of the discone antenna.

Base station for a radio communication system

Growing community of inventors

Kanagawa, Japan

Eiichi Kuroda