Communications: radio wave antennas – Antennas – Microstrip
Reexamination Certificate
2000-10-11
2001-07-24
Ho, Tan (Department: 2821)
Communications: radio wave antennas
Antennas
Microstrip
C343S848000
Reexamination Certificate
active
06266016
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a microstrip arrangement, preferably for use in a circuit board or in an antenna arrangement.
STATE OF THE ART
Microstrip technology is commonly used in arrangements within higher frequency ranges, for example the microwave range. Microstrip arrangements usually comprise a plane layer of an electrically conductive material arranged on a substrate of dielectric material. Common areas of application for microstrip arrangements are antennas and also circuit technology within the microwave range.
An extremely important and cost-influencing parameter in previously known microstrip arrangements is the material that is used as dielectric substrate. The material for the dielectric substrate is extremely important in known microstrip arrangements on account of inter alia the field losses that occur in the dielectric. In order to minimize these field losses, it has been necessary to use relatively expensive dielectric materials in previously known microstrip arrangements.
In conventional circuit board technology, for reasons of cost, use is made of dielectric materials which for inter alia the abovementioned reason are not suitable as a dielectric in microstrip arrangements. These inexpensive dielectric materials also have the disadvantage that their dielectric properties are not always the same at all points in one and the same circuit board.
In circuit board applications, it is also desirable for a conductor to be accessible from the outside of the circuit board. As conventional microstrip technology often makes use of a conductor that is “buried” in the dielectric, access to the conductor is rendered difficult.
A further problem with dielectric materials in microstrip conductors may be material variations between different deliveries of one and the same dielectric material from one and the same manufacturer.
One known way of reducing the field losses in the dielectric substrate in a microstrip arrangement is to provide the electrically conductive material with a non-plane design. A disadvantage of this solution is that a non-plane design drives up the manufacturing cost. Certain losses also occur in the electrically conductive material itself, compared with when the material is of plane design.
Another type of loss that may arise on account of the properties of the dielectric material is reflection losses, in other words losses at the point where the microstrip arrangement is connected to other equipment, in the case of an antenna especially transmitting or receiving equipment.
American Patent U.S. Pat. No. 4,521,755 discloses an arrangement which aims to improve the electrical properties in a transmission line made using strip line technology. This arrangement is dependent for its function on being positioned in a longitudinal cavity formed in a solid metal piece, which would seem to have the effect of making the arrangement bulky as well as costly to manufacture. The arrangement also requires the use of relatively expensive dielectric material, for example RT/DUROID 6010®.
DESCRIPTION OF THE INVENTION
A problem that is solved by means of the present invention is therefore that of minimizing, in an arrangement made using microstrip technology, the field losses that are caused by the dielectric material on which the conductive material is arranged.
Another problem that is solved by means of the present invention is that of minimizing the influence of material variations in the dielectric material in a microstrip arrangement.
A further problem that is solved by means of the present invention is that of reducing the reflection losses that arise in a microstrip arrangement.
By solving the abovementioned problems, it is possible to make use, in microstrip arrangements, of the type of dielectric that is used in conventional circuit board technology. As a result of this, microwave circuits can be connected to microstrip arrangements arranged on circuit boards that are manufactured using conventional circuit board technology. Furthermore, microstrip antennas can be manufactured using conventional circuit board technology. The manufacturing costs for said types of arrangement are thus reduced substantially.
These problems are solved by means of a microstrip arrangement that comprises a first and a second microstrip conductor. The two microstrip conductors have essentially the same dimensions in their longitudinal direction and transverse direction, and are galvanically interconnected by means of at least one connection. The two microstrip conductors also extend essentially parallel to one another on either side of a dielectric material.
As a result of this design of the microstrip arrangement, the field losses and also other influences caused by the dielectric material will be very considerably reduced, and in practice a resultant microstrip arrangement is obtained, which, with regard to its electrical performance, appears to be suspended in the air.
The microstrip arrangement also comprises one or more ground planes which extend essentially parallel to a plane defined by the extension of the two microstrip conductors in the longitudinal direction and transverse direction.
In a preferred antenna application, use is made of the microstrip arrangement according to the invention to excite radiating elements. In this application, ground planes are located parallel to the microstrip arrangement, on both its upper side and lower side. In the ground plane that is located on the same side of the microstrip arrangement as the radiating elements, there are apertures, above which apertures the radiating elements are located.
Measurements on this type of microstrip arrangement have also demonstrated considerably reduced reflection losses compared with previously known microstrip arrangements. The reduction is of the order of magnitude of 6 dB.
REFERENCES:
patent: 4494083 (1985-01-01), Josefsson et al.
patent: 4521755 (1985-06-01), Carlson et al.
patent: 4614922 (1986-09-01), Bauman et al.
patent: 4633262 (1986-12-01), Traut
patent: 4719470 (1988-01-01), Munson
patent: 4918457 (1990-04-01), Gibson
patent: 5386214 (1995-01-01), Sugawara
patent: 5532643 (1996-07-01), Kuffner et al.
patent: 5929728 (1999-06-01), Barnett et al.
patent: 0 671 777 (1995-09-01), None
patent: 0 801 433 (1997-10-01), None
Bergstedt Leif
Georgian Spartak
Burns Doane Swecker & Mathis L.L.P.
Ho Tan
Telefonaktiebolaget LM Ericsson (publ)
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