 Nonradiative dielectric waveguide and manufacturing method thereof |
| Accordingly, an essential object of the present invention is to provide a nonradiative dielectric ... |
|
| Alignment method |
| It is accordingly a primary object of the present invention to provide a solution obviating the ... |
|
| Automatic alignment system |
| It is an object of the present invention to provide an improved electro-optical alignment system ... |
|
| Telephone conference system with active analog conference |
| We claim as our invention: 1. A telephone conference system comprising a telephone conference ... |
|
| Exposure-scanning device |
| The object of the present invention is to provide an exposure-scanning device in which a mirror or ... |
|
| Speaker enclosure |
| What I claim is: 1. An improved speaker enclosure comprising: a tubular shaped enclosure body, ... |
|
| Multiple quadrature-phase amplitude modulating system capable of reducing a peak amplitude |
| What is claimed is: 1. A multiple quadrature-phase amplitude modulating system for modulating a ... |
|
| Replica circuit |
| OF THE EMBODIMENTS OF THE INVENTION In FIG. 2 the current in the high-voltage capacitor Ch passes ... |
|
|
Crystal filter structure
| Details |
Inventors: Augst, Horst G.;
Assignee: Telefonaktiebolaget L M Ericsson (Stockholm, SE)
Primary Examiner: Nussbaum; Marvin L.
Assistant Examiner:
Attorney, Agent or Firm: Hane, Roberts, Spiecens & Cohen
The invention relates to a crystal filter structure of polylithic type for realizing a filter with a number of links. The structure is formed by quartz crystal elements (21, R1, R2, 22, R3, R4, . . .) each containing two resonators (R1, R2) and associated electrode connections (301, 302, 311, 312). The quartz crystal elements are alternately arranged and fastened on mutual sides of a substrate plate (1), the resonators being galvanically connected through metallic layers (m21-23, m31-33, . . .) at one of the longitudinal edges of the substrate plate and the intermediate edge surface. The connections (312, 322, 332, 342, . . .) of the "hot" electrodes are suitably turned towards the substrate plate. The input and the output of the filter (A and B respectively) are arranged at the opposite placed short sides of the substrate plate and possible earth connections (0) are commonly connected through metallic layers (m01, m02, . . .) at the second longitudinal edge of the substrate plate. |
|
DETAILED DESCRIPTION When building crystal filter structures, like other electronic components, miniaturization and rational manufacturing procedures are sought.
At the same time the greatest possible distance between the filter input, the filter output and possible ground connections is aimed at, since it is important to be able to avoid, reduce or rearrange parasitic reactances, i.
e.
capacitances which can arise between the crystal elements and the capsule in addition with inductances formed by the lead-in wires.
Therefore it is advantageous to be able to provide a structure giving great freedom regarding the possibility of choosing suitable positions for the connections of the resonator electrodes.
The structure which is described below is a further development of the main idea behind the structure of polylithic crystal filters of the so called bilithic type and can be applied on crystal filters of the type being mentioned in the claim preamble.
One object of the present invention is to provide a crystal filter structure of the kind mentioned in the claim preamble, which gives an optimal distance between the filter input, the filter output and the ground connection in considering a high degree of miniaturization and influence of parasitic capacitances.
The structure is then characterized as appears from the characterizing part of the parent claims.
|
| Related patents |
|
|
Channel selector
What is claimed is: 1. A channel selector comprising: a phase locked loop (PLL) frequency synthesizer which synthesizes a local oscillation frequency corresponding to a ...
|
|
|
Fast settling phase locked loop
We claim: 1. A phase locked loop comprising: a voltage controlled oscillator (VCO) having a control input for receiving a drive voltage and an output, wherein the VCO ...
|
|
|
Electronic timepiece having a main oscillator circuitry and secondary oscillator circuitry
Generally speaking, in accordance with the instant invention, an electronic timepiece having a main oscillator circuit including a first time standard and a secondary ...
|
|
|
Atomic or molecular beam frequency standard with optical pumping and open resonator
Having described the invention I claim: 1. An atomic (molecular) resonance apparatus, particularly for the generation of a standard frequency, including: a source ...
|
|
|
Low-voltage, temperature compensated constant current and voltage reference circuit
Therefore, a general purpose of the present invention is to provide temperature compensated voltage and current level reference circuit capable of operating from low ...
|
|
|
Low voltage VCO temperature compensation
OF THE PREFERRED EMBODIMENT FIG. 1 includes a compensation circuit 10 and a voltage-controlled oscillator (VCO) circuit. The VCO circuit includes an LC tank circuit 20 ...
|
|
|
Temperature-compensated ring oscillator circuit formed on a semiconductor substrate
One object of the present invention is to compensate change of the oscillation frequency of a ring oscillator circuit caused by change of ambient temperature. Another ...
|
|
|
High resolution phase to sine amplitude conversion
OF A PREFERRED EMBODIMENT The present invention produces high accuracy sine amplitude data in a Direct Digital Synthesizer (DDS) circuit for conversion to a high ...
|
|
|
Microwave oscillator with temperature compensation
In view of the foregoing discussion, an object of this invention is to provide a lower-cost scheme for achieving temperature compensation in a microwave oscillator. A...
|
|
|
Dielectric waveguide
According to this invention, there is provided a dielectric waveguide comprising two flat conductive plates arranged in parallel with each other, a dielectric medium ...
|
|
|
Audio Signal Processing 
