US2969511A - Mechanical high frequency filters - Google Patents

Mechanical high frequency filters Download PDF

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Publication number
US2969511A
US2969511A US721277A US72127758A US2969511A US 2969511 A US2969511 A US 2969511A US 721277 A US721277 A US 721277A US 72127758 A US72127758 A US 72127758A US 2969511 A US2969511 A US 2969511A
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United States
Prior art keywords
resonators
couplers
wires
filter
filters
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Expired - Lifetime
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US721277A
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English (en)
Inventor
Borner Manfred
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Telefunken AG
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Telefunken AG
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Publication date
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/48—Coupling means therefor
    • H03H9/50—Mechanical coupling means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62J—CYCLE SADDLES OR SEATS; AUXILIARY DEVICES OR ACCESSORIES SPECIALLY ADAPTED TO CYCLES AND NOT OTHERWISE PROVIDED FOR, e.g. ARTICLE CARRIERS OR CYCLE PROTECTORS
    • B62J6/00—Arrangement of optical signalling or lighting devices on cycles; Mounting or supporting thereof; Circuits therefor
    • B62J6/01—Electric circuits
    • B62J6/015—Electric circuits using electrical power not supplied by the cycle motor generator, e.g. using batteries or piezo elements

Definitions

  • This invention relates to mechanical high-frequency filters preferably comprising cylindrical resonant bodies or resonators excited in longitudinal or torsional modes of oscillation, said resonators being coupled with one another and excited in the same oscillatory mode by means of cylindrical and co-axially disposed coupling elements or couplers (see: RCA Review of September 1949, pp. 348365).
  • Such filters are mostly made in a single unit, whereby the resonators and the couplers are considered as mechanically resonant lines.
  • the resonant lines have a length of M2 at the mean frequency of the pass band, for torsional or longitudinal modes of vibration.
  • quarter-wave length line elements are used as couplers.
  • the resonators and couplers are designed as co-axial conductors M2 or ) ⁇ /4 in length arranged in a row in such a way that, in case of longitudinally oscillating resonators, the couplers are also excited in longitudinal modes of oscillation.
  • band pass filters with a greater number of resonators comparatively long structures are obtained which can be manufactured only with difiiculty and are rather bulky.
  • the paths of oscillation of the resonators are adjacent one another and parallel and the couplers comprise wires or strips excited to oscillate in fiexural modes in directions which are transverse with respect to the oscillating directions of the resonators.
  • filters can be more easily manufactured and tuned, since the resonators can first be individually finished and tuned and thereafter attached to 2,969,511 Patented Jan. 24, 1961 ice the couplers, preferably by welding.
  • filters comprising longitudinally oscillating resonators are shorter in length, because not all of the rod-shaped resonators and the couplers are assembled in series on the same axis, i.e. the resonators are disposed parallel to each other, while the couplers are arranged transversely with respect to the direction of oscillation.
  • Fig. 1 shows schematically a three-stage mechanical band pass filter with electro-mechanical ferrite transducers at the input and output.
  • Fig. 2 illustrates schematically a similar filter to that shown in Fig. 1, in which the ferrite transducers are coupled in a modified way.
  • Figs. 3 and 4 show schematically a very simple embodiment of the filter according to the invention with the couplers comprising two continuous wires.
  • Fig. 5 illustrates schematically a part of a filter according to the invention, in which the resonators are modified.
  • Figs. 6 and 7 show schematically further embodiments of the invention in which four continuous wires are pronumber of these resonators.
  • resonators 1, 2 and 3 are provided which are excited in longitudinal modes of oscillation as indicated by arrows, and the ends of the resonators are interconnected by means of wires 4, 5, 6 and 7 welded to these ends, or secured by any other suitable means such as soldering, brazing, etc.
  • the oscillations of the resonator 1 have the greatest amplitudes at the ends thereof, at which points the wires 4 and 5 are subjected to the greatest bending stresses. As a result of this, the oscillations are transmitted to the resonator 2, and from there to the resonator 3 via the wires 6 and 7.
  • the filter comprises a greater or lesser Coupling of the electric oscillations to the resonators can be obtained in a manner known per se by means of magneto-strictive or other Fig. 2 shows a modified coupling arrangement for the ma'gheto-strictive transducers.
  • the ferrite oscillators 8 and 9 are coupled to the resonators 1 and 3 by means of wires 16, 17, 18 and 19, respectively, in the same way as the resonators 1, 2 and 3 are interconnected, said wires being subjected to bending stresses.
  • Fig. 4 shows an embodiment, in which the centers of the resonators at their ends are welded to the continuous wires or 21.
  • each resonator is rounded to form semispherical caps or calottes, whereby the propagation of spurious frequencies can be safely avoided.
  • coupler wires 22, 23, 24 and 25 coincide with the edges of a rectangular prism and the resonators 1, 2 and 3 are secured between these wires by welding them to the two ends or side edges of these bodies at opposite points.
  • FIG. 7 A modification of the latter arrangement is shown in Fig. 7, in which the coupler wires are welded to intermediate points on the cylindrical surfaces of the resonators, at which points the oscillating amplitudes are lower, resulting in a weaker coupling effect between the individual resonators.
  • any number of resonators other than that shown in Figs. 1 to 7 can be selected according to the requirements of filter characteristics and cutoif slope. Coupling of electrical vibrations may be obtained by other suitable mechanical transducers than those shown in Figs. 1 and 2. An illustration of such elements is unnecessary, since the present invention is not directed to the exciting means as such.
  • the shape of the resonators need not be cylindrical as illustrated in the drawings, i.e. it may be prismatic, having rectangular or a square cross-section.
  • a mechanical filter comprising at least two elongated resonators each tuned to vibrate in a longitudinal mode at a common selected frequency, said resonators being disposed side-by-side in spaced mutually parallel orientation with vibrational antinodes substantially in transverse alignment; non-resonant couplers for coupling adjacent resonators with one another, said couplers comprising spring-like filar elements disposed transversely across said resonators and fixed thereto in the vicinity of aligned antinodes, whereby the couplers transmit vibrations between the resonators by fiexural oscillation; and motion transducer means coupled with at least one of said resonators, and each transducer means having its direction of motion disposed longitudinally of the ISO- nator to which it is coupled.
  • a filter according to claim 1 characterized in that separate couplers are secured to the respective end surfaces of the resonators.
  • a filter according to claim 1 characterized in that said couplers comprise continuous wires secured to more than two resonators.
  • a filter according to claim 1 characterized in that said couplers are securedto the center points of the end surfaces of said resonators.
  • a filter according to claim 4 characterized in that the end surfaces of said resonators are rounded.
  • a filter according to claim 1 characterized in that said couplers are secured to said resonators at points which each lies intermediate the longitudinal ends thereof and spaced therefrom.
  • a filter according to claim 1 characterized in that said resonators comprise M2 resonators having longitudinal outer surfaces intersecting resonator end surfaces, and said couplers comprising four wires disposed across the resonators with two wires adjacent each end surface and connected to the intersections of end and longitudinal surfaces at transversely spaced points.

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  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
  • Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
US721277A 1957-03-20 1958-03-13 Mechanical high frequency filters Expired - Lifetime US2969511A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE355872X 1957-03-20

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US2969511A true US2969511A (en) 1961-01-24

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US721277A Expired - Lifetime US2969511A (en) 1957-03-20 1958-03-13 Mechanical high frequency filters

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US (1) US2969511A (enrdf_load_stackoverflow)
CH (1) CH355872A (enrdf_load_stackoverflow)
DE (1) DE1252817B (enrdf_load_stackoverflow)
FR (1) FR1191701A (enrdf_load_stackoverflow)
GB (1) GB842194A (enrdf_load_stackoverflow)
NL (1) NL113896C (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3372351A (en) * 1963-01-18 1968-03-05 Telefunken Patent Mechanically strong mechanical resonant filter having weak coupling between resonators
JPS49120151U (enrdf_load_stackoverflow) * 1973-02-12 1974-10-15
US3874041A (en) * 1972-06-13 1975-04-01 Dzus Fastener Co Fasteners
JPS5091438U (enrdf_load_stackoverflow) * 1973-12-21 1975-08-01
US3931600A (en) * 1973-06-11 1976-01-06 Kokusai Electric Co., Ltd. Mechanical filter
US4241321A (en) * 1978-02-15 1980-12-23 Fujitsu Limited Electromechanical filter
US20080006198A1 (en) * 2006-06-24 2008-01-10 Joseph Angelini Boat foldable into a compact self-contained shape

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2360212A1 (fr) * 1976-07-26 1978-02-24 Lignes Telegraph Telephon Perfectionnement au couplage pour filtres electromecaniques

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1788519A (en) * 1926-05-26 1931-01-13 Western Electric Co Mechanical transmission system
US1933306A (en) * 1931-04-30 1933-10-31 Gen Electric Electrical frequency analyzer
US2318417A (en) * 1942-06-02 1943-05-04 Gen Electric Artificial reverberation system
US2615981A (en) * 1949-01-14 1952-10-28 Collins Radio Co Electromechanical filter
US2738467A (en) * 1953-03-12 1956-03-13 Rca Corp Mechanical resonator coupling utilizing poisson's effect
US2799832A (en) * 1953-09-11 1957-07-16 Motoroln Inc Electromechanical filter
US2814785A (en) * 1955-07-29 1957-11-26 Rca Corp Electromechanical filter
US2829350A (en) * 1955-08-16 1958-04-01 Collins Radio Co Mechanical filter with coupling wires
US2856588A (en) * 1956-03-01 1958-10-14 Rca Corp Mechanical filter

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1788519A (en) * 1926-05-26 1931-01-13 Western Electric Co Mechanical transmission system
US1933306A (en) * 1931-04-30 1933-10-31 Gen Electric Electrical frequency analyzer
US2318417A (en) * 1942-06-02 1943-05-04 Gen Electric Artificial reverberation system
US2615981A (en) * 1949-01-14 1952-10-28 Collins Radio Co Electromechanical filter
US2738467A (en) * 1953-03-12 1956-03-13 Rca Corp Mechanical resonator coupling utilizing poisson's effect
US2799832A (en) * 1953-09-11 1957-07-16 Motoroln Inc Electromechanical filter
US2814785A (en) * 1955-07-29 1957-11-26 Rca Corp Electromechanical filter
US2829350A (en) * 1955-08-16 1958-04-01 Collins Radio Co Mechanical filter with coupling wires
US2856588A (en) * 1956-03-01 1958-10-14 Rca Corp Mechanical filter

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3372351A (en) * 1963-01-18 1968-03-05 Telefunken Patent Mechanically strong mechanical resonant filter having weak coupling between resonators
US3874041A (en) * 1972-06-13 1975-04-01 Dzus Fastener Co Fasteners
JPS49120151U (enrdf_load_stackoverflow) * 1973-02-12 1974-10-15
US3931600A (en) * 1973-06-11 1976-01-06 Kokusai Electric Co., Ltd. Mechanical filter
JPS5091438U (enrdf_load_stackoverflow) * 1973-12-21 1975-08-01
US4241321A (en) * 1978-02-15 1980-12-23 Fujitsu Limited Electromechanical filter
US20080006198A1 (en) * 2006-06-24 2008-01-10 Joseph Angelini Boat foldable into a compact self-contained shape
US7530322B2 (en) 2006-06-24 2009-05-12 Angelini Joseph A Boat foldable into a compact self-contained shape

Also Published As

Publication number Publication date
GB842194A (en) 1960-07-20
NL113896C (enrdf_load_stackoverflow)
CH355872A (de) 1961-07-31
DE1252817B (enrdf_load_stackoverflow)
FR1191701A (fr) 1959-10-21

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