Specification of the invention (patented)of a coaxial cable beam antenna(directional) to replace existingparabola antenna.
This is an antenna which uses existing coaxialcable which is readily vailable at low cost.It consists of an arrangementof half wave length slots in coaxial cable which produces a beam antennawith good high frequency characteristics, which is easy to handle at lowcost.
EnlargedCross Section of Coaxial Cable It has the following features ;
1.There is a relationship between the length and angle of the slots in the cable, helix form, and the inner diameter of the outer conductor.
2.By the imperatives of mass production the outer diameter is under 20 mm.
3.The inner diameter of the outer conductor is the decisive factor for the transmission frequency, this will cut out if the wavelength becomes a half.
4.Based on the requirements specified in 1,2 and 3 above the optimal frequencies are in the range of 2 to 20 GHz.
5.As the transmission line and the antenna are integrated the beam antenna does not require a transducer.
6.As the antenna and the electro magnetic waves through the slotted coaxial cable are coupled there is good directional capability with high gain.
7.The direction of the beam can be controlled provided the phase in the transmission line is related to the position of the slots in the cable.
8.By the antenna being integrated into the cable it has durability and can be shaped and easily installed with easy access to the wiring.
9.It can produce low or high gain（of a directional antenna).
10.A beam antenna based on this patent，usable in the frequency range of 2 to 20GHz. has multi purpose application which can lead to the development of new products.
11.As it utilizes an existing product and replaces existing antenna，it represents no added threat to the environment．
Possible fields in which the basic patent can bedeveloped and utilized；- *
As receiving antenna for satellite broadcasting（BS/CS） *
As communication transmission and receiving antenna with and between vehicles． *
As antenna for automatic road and highway driving systems. *
As antenna in ground stations for overcoming poor reception on cellular telephones.
The following patents for the beam antenna havebeen granted to the Beam Co., Ltd.; - Country Patent Number
|3．France||8912468（de publication2 652 453）|
6. Germany ROLL ennummer
|G89 16 262.5|
7. Japan Patent pending and to the Shinkoh Manufacturing Co.，Ltd.：−
8. Japan All enquires should be made to ; -
Shinkoh Manufacturing Co., Ltd. And/ or Beam Co., Ltd. 5131 Taguchi,Usudamachi,Minamisakugun,Naganoken,384-04 JAPAN
TEL: 0267-82-2511 FAX: 0267-82-5757