The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 29, 1994
Filed:
Jul. 15, 1993
Minori Kawano, Gunma, JP;
Kohji Ogawa, Gunma, JP;
Sadayuki Tsukagoshi, Gunma, JP;
Hiroyuki Kuroiwa, Gunma, JP;
Masato Sato, Gunma, JP;
Yasuhiro Ishizaki, Kanagawa, JP;
Fumiaki Komatsu, Kanagawa, JP;
Eiichi Kuroda, Kanagawa, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
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.