Wave transmission lines and networks – Coupling networks – Delay lines including long line elements
Patent
1987-12-02
1990-01-16
Nussbaum, Marvin L.
Wave transmission lines and networks
Coupling networks
Delay lines including long line elements
333 23, 333162, 333163, 29600, H01P 900, H01P 902, H01P 1100
Patent
active
048946281
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
This invention relates to an improved transmission lilne device for delaying electromagnetic energy and a method of manufacturing such a device.
Hollow metallic tubes (waveguides) of various transverse cross-sectional shapes exhibit well-known properties which fit them for use as a delay mechanism for electromagnetic waves. Such tubes, which propagate TE waves, are characterised by a wide bandwidth capability and a low insertion loss which is essentially constant over the operating range.
The family of transmission lines which include suspended stiplines, image line, coaxial line, and so on, propagate TEM or quasi-TEM waves and are also suitable for use as delay lines, but such devices, in general, exhibit a higher insertion loss due, in part, to energy losses in the dielectric component.
The cost of amplification at microwave frequencies is high. Consequently insertion loss will be an important consideration where a design calls for a substantial delay. The use of a waveguide may be indicated by virtue of its characteristic low insertion loss, but where the design is also sensitive to cost, weight and volumetric efficiency, the deployment of many metres of commercial waveguide section is likely to pose a problem.
According to our earlier invention, as published under PCT No. AU85/00171, an improved waveguide delay line is disclosed comprising a helical conducting channel formed in a cylinder, such as by machining, such channel being closed by a tightly-fitting conducting sleeve.
The method there disclosed, of fabricating a waveguide delay line for use at microwave frequencies, teaches a way of retaining the low insertion loss characteristic of a waveguide, whilst affording improved volumetric efficiency, low weight and low cost of manufacture. In addition, a delay line so constructed can be integrated into a parent structure as a load-bearing member.
It will be appreciated that in many weight-sensitive applications this duality of electronic function and mechanical load-bearing capability enhances the cost-effectiveness of the method of fabrication disclosed.
In summary, a waveguide delay line as described in the earlier Patent specification confers certain advantages: member occupying minimum volume;
SUMMARY OF THE INVENTION
The object of the present invention is to provide an improved transmission line device for use as a delay mechanism by using the general method of construction of the invention referred to earlier herein, but with the addition of a conducting member supported within the said helical channel.
With such an addition well-known forms of transmission, line suitable for use as a delay line can be fabricated such as, for example, suspended strip line and co-axial line, but which now, by virtue of the present invention, shows an improved electrical performance, whilst also possessing the advantages indicated in (a), (b), (c) and (d) above.
Accordingly, the present invention comprises a transmission delay line characterised by a helical channel formed in the wall of a cylinder to give an elongated helical path for a travelling wave. A conductive sleeve fitting over the said cylinder closes the channel, the said channel being characterised by a helical conducting member in the channel separated from the walls of the channel by a dielectric material, which may be in the form of a continuous bed or discrete spacers.
DESCRIPTION OF THE DRAWINGS
To enable the invention to be fully appreciated, embodiments thereof will now be described with reference to the accompanying drawings, but the invention need not necessarily be limited to the form shown.
In the drawings,
FIG. 1 and 2 are a longitudinal sectional view and a transverse sectional view on line 2--2 of FIG. 1 respectively, of a preferred form, of the transmission delay line of the present invention
FIG. 3 shows the components of the line of FIGS. 1 and 2, before assembly,
FIG. 4 shows a method of assembly, of the line of FIGS. 1-3
FIG. 5A and 5B show examples of dielectric support geometry suitable for circul
REFERENCES:
patent: 3199054 (1965-08-01), Holland et al.
WO,A, 86/01039 (The Commonwealth of Australia) Feb. 13, 1986.
Nussbaum Marvin L.
The Commonwealth of Australia
LandOfFree
Transmission delay line and method of manufacture does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Transmission delay line and method of manufacture, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transmission delay line and method of manufacture will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1337363