Wave transmission lines and networks – Plural channel systems – Having branched circuits
Reexamination Certificate
1999-06-10
2001-12-18
Lee, Benny (Department: 2817)
Wave transmission lines and networks
Plural channel systems
Having branched circuits
C333S248000, C333S208000, C333S219100
Reexamination Certificate
active
06331809
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a nonradiative dielectric waveguide resonator, a nonradiative dielectric waveguide filter, a duplexer and a transceiver incorporating the same, used in a motor-vehicle-mounted radar in the millimeter wave band and the microwave band, wireless LAN, or the like.
2. Description of the Related Art
A description will be given of a conventional nonradiative dielectric waveguide filter referring to FIG.
23
.
FIG. 23
is a perspective view of a conventional nonradiative dielectric waveguide filter, in which the upper conductor plate is omitted for convenience sake.
The filter
110
a
is composed of parallel upper and lower conductor plates
111
made of aluminum, etc., and a dielectric strip
112
made of polytetrafluoroethylene, etc., which is disposed between the upper and lower conductor plates
111
. The dielectric strip
112
is composed of resonator parts
115
and input-output connection unit parts
116
, which are arranged apart from each other. The resonator parts
115
of the dielectric strip
112
and the upper and lower conductor plates
111
form a nonradiative dielectric waveguide resonator, whereas the input-output connection unit parts
116
of the dielectric strip
112
and the upper and lower conductor plates
111
form input-output connection units.
In the nonradiative dielectric waveguide, the distance between the upper and lower conductor plates
111
is set to no more than a half wavelength of the frequency used. This permits a position in which the dielectric strip
112
is present to be a signal-transmitting region and permits a position in which the dielectric strip
112
is not present to be a cut-off region. Thus, signals transmitting through the input-output connection unit couple to the nonradiative dielectric waveguide resonator through the distance between the input-output connection unit parts
116
and the resonator parts
115
of the dielectric strip
112
so as to resonate with a resonance frequency determined, for example, by the length of the signal-transmitting direction of the dielectric strip
112
. After coupling to the input-output connection unit, signals are output, in which the nonradiative dielectric waveguide filter
110
a
acts as a band pass filter.
Additionally, a description of another conventional embodiment will be provided referring to a perspective view of FIG.
24
. The same reference numerals are given to the same parts as those in the first conventional embodiment, and only a brief explanation is given.
As shown in
FIG. 24
, the nonradiative dielectric waveguide filter
110
b
employed in a second conventional embodiment is also composed of the upper and lower conductor plates
111
and the dielectric strip
112
disposed between the upper and lower conductor plates
111
. In this embodiment, the resonator parts
115
and the input-output connection unit parts
116
of the dielectric strip
112
are connected by a dielectric strip having a narrower width. When the width is significantly narrowed as shown in
FIG. 24
, the part is allowed to be a cut-off region. Thus, the nonradiative dielectric waveguide filter
110
b
shown in
FIG. 24
also acts as a band pass filter, as in the case of the first conventional embodiment.
Primarily, in a nonradiative dielectric waveguide filter, the length of the signal-transmitting direction of a resonator part of a dielectric strip determines a resonance frequency, the distance between resonator parts determines a coefficient of coupling, and the distance between an input-output connection unit part and the resonator part determines an external Q.
In the first conventional embodiment, however, the resonator part and the input-output connection unit part of the dielectric strip are arranged apart from each other. As a result, fine adjustment between their arranged positions is necessary to obtain required characteristics. Furthermore, even after the formation of the nonradiative dielectric waveguide filter, for example, shocks from the outside cause changes in their arranged positions so that filter characteristics are also changed.
Meanwhile, in the second conventional embodiment, since the resonator part and the input-output connection unit part of the dielectric strip are connected, their arranged positions are not likely to change. However, it is difficult to manufacture such an approximately 1-2 mm wide dielectric strip so as to make it compliant with required filter characteristics.
SUMMARY OF THE INVENTION
In the light of the above-described problems, the present invention has been made to solve them. It is an object of the present invention to provide a nonradiative dielectric waveguide resonator and a nonradiative dielectric waveguide filter which permit easy manufacturing and have stable characteristics, and a duplexer and a transceiver which incorporate the same.
To this end, according to an aspect of the present invention, there is provided a nonradiative dielectric waveguide resonator including two planar conductors disposed substantially parallel to each other with a dielectric strip disposed therebetween, having substantially constant cross-sectional shape, taken perpendicular to a signal-transmitting direction, at least one resonance region formed within dielectric and cut-off regions formed within the dielectric strip on both sides of the resonance region in the signal-transmitting direction.
This arrangement enables use of the dielectric strip having substantially constant cross-sectional shape, taken perpendicular to a signal-transmission direction, so that a nonradiative dielectric waveguide resonator which permits easy manufacturing and has stable characteristics can be obtained.
Preferably, the dielectric strip of the nonradiative dielectric waveguide resonator is formed of a dielectric material having uniform dielectric constant.
Since this arrangement permits use of the dielectric strip formed of the same material, a nonradiative dielectric waveguide resonator, which can be more easily manufactured, is obtainable.
Furthermore, in the nonradiative dielectric waveguide resonator, a main signal-transmitting mode is preferably the LSM mode; a first groove having a bottom and conductor walls may be disposed in a position in which the conductors are opposing; the resonance region may be formed by fitting the dielectric strip into the first groove; and the cut-off regions may be formed either by a second groove having lower conductor walls than those of the first groove or by portions of the conductors having no grooves.
This permits a nonradiative dielectric waveguide resonator using the LSM mode to be easily obtained.
Furthermore, the first groove of the nonradiative dielectric waveguide resonator may include a bottom and conductor walls of a specified height or higher.
This permits use of the LSM mode as a single mode at the used frequency.
Additionally, in the nonradiative dielectric waveguide resonator, a main signal-transmitting mode may be the LSE mode; a first groove having a bottom and conductor walls may be disposed in a position in which the conductors are opposing; the cut-off regions may be formed by fitting the dielectric strip into the first groove; and the resonance region may be formed either by fitting the dielectric strip into a second groove having lower conductor walls than those of the first groove or by disposing the dielectric strip between the conductors having no grooves.
This permits a nonradiative dielectric waveguide resonator using the LSE mode to be easily obtained.
According to another aspect of the present invention, there is provided a nonradiative dielectric waveguide filter including two planar conductors disposed substantially parallel to each other, a dielectric strip having substantially the same shape of sections, which are perpendicular to a signal-transmitting direction, in which input-output connection units formed by disposing the dielectric strip between the conductors are coupled to the nonradiative dielectric waveguide resonator described ab
Hiratsuka Toshiro
Takakuwa Ikuo
Tanizaki Toru
Jones Stephen E.
Lee Benny
Murata Manufacturing Co. Ltd.
Ostrolenk Faber Gerb & Soffen, LLP
LandOfFree
Nonradiative dielectric waveguide resonator, nonradiative... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Nonradiative dielectric waveguide resonator, nonradiative..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nonradiative dielectric waveguide resonator, nonradiative... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2589693