摘要:
A CM type directional coupler comprises a body having a dielectric layer, an annular magnet buried in the dielectric layer, a pair of transmission lines juxtaposed with a predetermined spacing between them in a magnetic area enclosed by the magnetic ring in the dielectric layer, and lead terminals extending from opposite ends of each of the transmission lines to outside of the dielectric layer, and all these elements are formed integrally with each other to provide a single device. Therefore, a large coupling factor and directivity are ensured, and the coupler can be designed very compact. This directional coupler can be manufactured with a highly improved yield and mass-producibility, so it is very suitably usable as a power detector in a portable telephone.
摘要:
There is disclosed a method of aligning an azimuth of an antenna by use of an antenna azimuth aligning instrument capable of economically and precisely aligning the azimuth in a case where a direction of a main beam of a directional antenna is matched with a counter antenna. There is provided a method of aligning the azimuth of the directional antenna by use of the antenna azimuth aligning instrument to be attached to the antenna for use in radio communication, the azimuth aligning instrument includes an aiming hole whose central axis is constituted in parallel with a main beam azimuth of the antenna and in which a diameter of an opening 2C on an operator's viewing side is set to be larger than that of an opening 2B on a target side, and the azimuth of the antenna is aligned using the centers of the two openings of the aiming hole as aims for a target.
摘要:
Radio communication systems, e.g. cellular telephones, have employed a space diversity antenna system which includes a plurality of antennas. In the space diversity antenna system for use in the cellular telephone, since two antennas are positioned adjoining each other, the space diversity effect cannot be adequately provided. To solve this problem, the polarization diversity antenna system according to this invention incorporates a first antenna, a second antenna, and a conductive board on which the second antenna is fixed at a given position, thus preventing the current flowing in the conductive board from causing the reception characteristic of the second antenna to deteriorate.
摘要:
The cell expansion system and method maximize the use of communication signal resource such as frequencies and polarized waves in expanding base stations for wireless communication. The cell are divided into four equal sectors, and at least a pair of adjacent sectors of the adjacent cells shares a common signal for wirelessly communicating with each other.
摘要:
A slot array antenna with a cavity of a simple construction having a plurality of slots formed on a dielectric substrate and capable of providing good directional characteristics while minimizing inter-slots coupling. The slot array antenna (1) includes a power supply line in the form of a micro-strip line formed on one surface of the dielectric substrate, a slot antenna portion (10) with a plurality of slots (14a, 14b, 14c, 14d) formed on the other surface of the dielectric substrate in an array-like fashion so as to extend perpendicularly to the micro-strip line with the dielectric substrate interposed therebetween, and a reflector (40) with a cavity (42) having an opening disposed in opposition to a plane on which the plurality of slots (14a, 14b, 14c, 14d exist). In this case, if the cavity has a width narrow enough to cut off a frequency of radio waves to be used, the directionality of the slot array antenna 1 can be optimized.
摘要:
An intermediate frequency filter for an intermediate frequency used in the receiver section of a digital radio communications apparatus is composed of an amplitude-flat ceramic filter incorporating two ceramic resonators, a buffer means and a single tuning circuit having the center frequency thereof within the bandwidth of the amplitude-flat ceramic filter, all being connected in series with each other. The center frequency of the single tuning circuit and Q are adjusted to approximate the amplitude characteristic of the intermediate frequency filter to that of TBT filter (0.4.ltoreq.parameter m.ltoreq.1.0).
摘要:
A branching filter for separating or combining two different frequencies without interference in radio communication equipment etc. One or both of two filter blocks for separating or combining two signal waves whose central frequency differ from each other are constructed from a dielectric bandpass filter which allows the desired wave of a block to pass and a SAW band stop filter being connected in series with said filter which allows the desired wave of a block to pass and stops passing of the desired wave of another block.
摘要:
A wireless system for use in a low power data communications in a sub-millimeter wave zone includes at least one wireless communications device including a directional antenna whose cross-polarization discrimination is not less than 24 dB, wherein the wireless system uses a plurality of planes of polarization selectively. The planes of polarization to be used are selected such that the number of non-occupied channels is largest by detecting the number of non-occupied channels depending on planes of polarization. The directional antenna, having a box shape whose front view is a right square, is formed as a single body with the wireless communications device, and the wireless communications device is fixed to a pole in a way that each side of the right square is slanted at 45° with respect to the pole.
摘要:
There is disclosed a method of aligning an azimuth of an antenna by use of an antenna azimuth aligning instrument capable of economically and precisely aligning the azimuth in a case where a direction of a main beam of a directional antenna is matched with a counter antenna. There is provided a method of aligning the azimuth of the directional antenna by use of the antenna azimuth aligning instrument to be attached to the antenna for use in radio communication, the azimuth aligning instrument includes an aiming hole whose central axis is constituted in parallel with a main beam azimuth of the antenna and in which a diameter of an opening 2C on an operator's viewing side is set to be larger than that of an opening 2B on a target side, and the azimuth of the antenna is aligned using the centers of the two openings of the aiming hole as aims for a target.
摘要:
A wireless system for use in a low power data communications in a sub-millimeter wave zone includes at least one wireless communications device including a directional antenna whose cross-polarization discrimination is not less than 24 dB, wherein the wireless system uses a plurality of planes of polarization selectively. The planes of polarization to be used are selected such that the number of non-occupied channels is largest by detecting the number of non-occupied channels depending on planes of polarization. The directional antenna, having a box shape whose front view is a right square, is formed as a single body with the wireless communications device, and the wireless communications device is fixed to a pole in a way that each side of the right square is slanted at 45° with respect to the pole.