Electrical transmission or interconnection systems – With harmonic filter or neutralizer
Reexamination Certificate
1999-05-19
2001-07-03
Paladini, Albert W. (Department: 2841)
Electrical transmission or interconnection systems
With harmonic filter or neutralizer
C333S202000, C333S209000
Reexamination Certificate
active
06255745
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an arrangement for the frequency-selective suppression of high frequency signals. In particular, it relates to an arrangement for suppressing undesired signal frequencies within a transmitting and/or receiving device.
2. Prior Art
In transmitting and/or receiving devices, to generate or process high frequency signals, auxiliary signals are often needed that are generated with the aid of an oscillator. One example of this is the frequency signal of a receiving oscillator (local oscillator) in a receiving device on the superheterodyne principle. Such auxiliary signals, however, should as a rule not be capable of escaping, or should be capable of escaping only within a narrowly defined frequency range, from the circuit component for which they are needed. To prevent these auxiliary signals from leaving the prospective circuit component, it is known to use shielding baffles, shielding housings, and also filter means as options. The better the suppression of undesired signal frequencies is supposed to be, the greater is the requisite effort and expense, as a rule.
Over the course of technological development in the context of high-frequency technology, increasingly more circuits in microline technology are employed. It is possible in principle also to make filter circuits for suppressing undesired signal frequencies by this technology. However, they often lack the requisite quality, selectivity or selection for complete suppression of undesired signal frequencies. High-frequency filters that have higher quality are known in the form of cavity resonators. It is also known to combine microline technology circuits with such cavity resonators. This makes it possible, even in a component group made by microline technology, to achieve a filter circuit of the highest possible quality. One example of such an arrangement is described in International Patent Disclosure WO 92/13371. This reference relates to an arrangement and a method for coupling a microline circuit to a cavity resonator. The arrangement includes a substrate plate, with the microline circuit provided on one side and the ground plane provided on the other. A cavity resonator is also present. According to this reference, the microline circuit is coupled to the cavity resonator with the aid of a slit, provided in the ground plane, and a planar radiator, which is disposed between the ground plane and the cavity resonator.
Another transition from a microline circuit to, in this case, a hollow conductor is known from German Patent Disclosure DE 42 41 635 Al. Here the microline changes over to a unilateral suspended-substrate line, and a space located above this line on the opposite side of the substrate is widened to a cross section equivalent to the cross section of the adjoining hollow conductor.
In these known couplings, difficulties can arise above all from mechanical strains between the substrate of the microline circuit and the hollow conductor or cavity resonator. These strains are due to different temperature-dependent coefficients of expansion of the different materials. The known couplings are often also difficult to achieve because the assembly and connection of the microline with the cavity resonator must typically be done highly exactly. Another disadvantage that can be named is that in the filter arrangement of WO 92/13371, the high frequency signals to be filtered are coupled in and out via one and the same coupling terminal. It cannot be entirely precluded that at least some undesired high frequency signals will be transmitted directly from the input of the filter arrangement to the output.
SUMMARY OF THE INVENTION
The object of the present invention is to disclose an arrangement of the above generic type which is suited for use in conjunction with microline circuits, has high quality, and at the same time is simple and economical to produce.
According to the invention the arrangement for frequency-selective suppression of high frequency signals at undesired signal frequencies within a transmitting device, a receiving device or a transmitting and receiving device, comprises a common substrate plate; separate substrate faces spaced from each other on the common substrate plate; a hood disposed on or above the common substrate plate to form a hollow chamber between the hood and the common substrate plate, which is bounded by electrically conductive walls; respective coupling terminals for coupling the high frequency signals into and out of the hollow chamber, which are radiator elements embodied by respective striplines, and the hood being arranged on the substrate plate to cover the radiator elements. One radiator element is connected with the transmitting device, receiving device or transmitting and receiving device to couple in the high frequency signals into the hollow chamber and another radiator element is connected with the transmitting device, receiving device or transmitting and receiving device to couple the high frequency signals out of the hollow chamber.
Advantageous modifications and further embodiments are described hereinbelow. The invention can be realized especially advantageously in combination with a housing of a shielding housing, as is shown in an example in FIG.
3
. The arrangement of the invention is preferably used in such a case for the frequency-selective coupling in of signal frequencies into the shielding housing and/or the frequency-selective outcoupling of signal frequencies from the shielding housing.
It is an advantage of the invention that with it a filter arrangement for use in a microline circuit is disclosed that has high quality and accordingly is highly suitable for suppressing undesired signal frequencies. It proves to be an advantage that because the substrate faces are disposed separately from one another, both direct-current decoupling and an avoidance of direct overcouplings of surface waves are attained. This contributes substantially to good suppression of undesired signal frequencies. In an advantageous refinement of the arrangement the hood is disposed above the substrate faces without being directly secured to them or with an air gap between it and the substrate faces, mechanical strains, which can arise from different temperature-dependent expansions of the stripline substrate and the hollow chamber, are reliably avoided. The arrangement of the invention is also insensitive in terms of tolerances in assembly and accordingly requires no calibration. The arrangement of the invention is furthermore insensitive in terms of tolerances with regard to the substrate thickness of the stripline circuit. Another particular advantage of the invention is that the substrate or the stripline circuit needs to be machined on only one side. By comparison, in the arrangement of WO 92/13371, for instance, it is necessary to make a slit in the ground plane of the stripline substrate, and thus both sides of the substrate have to be machined. The situation is similar for the transition to the suspended-substrate line of DE 42 41 635 A1. In summary, the stated arrangement can thus be realized simply and economically and is also easy to produce in large scale mass production. A very particular advantage of the invention is obtained if the aforementioned arrangement is integrated with an existing shielding housing. This advantageous feature of the invention is described in further detail in FIG.
3
.
REFERENCES:
patent: 4796079 (1989-01-01), Hettiger
patent: 5365209 (1994-11-01), Ito et al.
patent: 5506553 (1996-04-01), Makita et al.
patent: 5796323 (1998-08-01), Uchikoba et al.
patent: 5880652 (1999-03-01), Snel
patent: 5900796 (1999-05-01), Parker
patent: 42 41 635 A1 (1994-06-01), None
patent: WO 92/13371 (1992-08-01), None
Bertsch Guenter
Martin Siegbert
Miosga Klaus-Dieter
Paladini Albert W.
Robert & Bosch GmbH
Striker Michael J.
LandOfFree
Arrangement for frequency-selective suppression of high... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Arrangement for frequency-selective suppression of high..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Arrangement for frequency-selective suppression of high... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2475787