摘要:
A solid state electronic device having a thin film of an Al (aluminum) alloy Li (lithium) on the surface of a substrate for a surface acoustic wave (SAW). Interdigital electrodes, electric wiring patterns and bonding pads are formed by the thin film of the Li-added Al alloy. This thin film suppresses migration which occurs when a high density current is supplied to the device or a large amplitude SAW is generated. The thin film, which provides a small loss and relatively low hardness, provides a desired power handling capability and high yield of wire bonding. The this film assures high endurance to failure of the device and sufficient life of the device.
摘要:
In an apparatus for descrambling a scrambled television signal, an elastic surface wave filter is used. This elastic surface wave filter has an interdigital electrode having an electrode pattern similar to at least portion of the waveforms of a luminance signal section of the scrambled television signal to be input. The elastic surface wave filter generates a response pulse only when the waveforms which are analogous to the electrode pattern of the interdigital electrode of the scrambled television signal were input, thereby descrambling the television signal using this response pulse.
摘要:
Disclosed is a surface acoustic wave transmission device comprising a piezoelectric substrate provided thereon with an input and output transducers for transmitting and receiving the surface acoustic wave, a package for accommodating the piezoelectric substrate, and an adhesion layer for fixing the bottom of the piezoelectric substrate to the ground plane of the package. The adhesion layer is made to have a thickness of .lambda..sub.R /2.6 or more wherein .lambda..sub.R : is the wave length of the surface acoustic wave at the main lobe of the operating frequency, so that unnecessary waves caused by bulk wave components are absorbed.
摘要:
When SAW filter is used as a receiving filter of an antenna duplexer filter in a cellular radio equipment, since a transmitting signal of an out-band frequency has a large power for the SAW filter, the large power can leak into the SAW filter to generate inter-modulation disturbances in the SAW filter. Since the inter-modulation disturbances are generated when the transmission power density of the surface acoustic wave is made too large, input converters are divided, and the divided converters are disposed in the direction perpendicular to the propagation direction of the surface acoustic wave to lower the transmission power density. Since the divided converters are connected in series, reduction in the impedence together with increase of the aperture length can be compensated.
摘要:
A SAW device having a piezoelectric substrate and interleaved metal electrodes formed on the substrate, in which the formation of the electrodes on the substrate is carried out by sputtering. Further, the metal electrodes may contain an additive of Cu, Ti, Zn, Mg, Fe, Ni, Cr, Ga, Ge, Sn, Pd or Ta. The resulting SAW device is capable of dealing with high frequency electric signals of a larger amplitude, or higher power electric signals, as compared with the conventional SAW device.
摘要:
In a SAW device comprising a piezoelectric substrate and at least one set of metallic electrodes formed on the piezoelectric substrate, at least one set of the electrodes have a laminated structure comprised of a layer of an aluminum film added with an impurity at a concentration of 6 wt. % or less and another layer of a film of pure aluminum or aluminum added with an impurity at a concentration of 0.4 wt. % or less. The SAW device having the laminated structure of electrodes can handle high frequency electric signals of higher power and/or larger amplitudes.
摘要:
A surface acoustic wave (SAW) device comprises a piezo-electric surface acoustic substrate, and plural sets of input/output interdigital electrodes disposed on the substrate. A phase shifter is provided between a sending electrode and a reflecting electrode included in the input or output interdigital electrodes for producing an electrical phase difference to implement a unidirectional electrode. The sending electrode and the reflecting electrode are mutually connected through the phase shifter including two pure reactance elements serially connected between the sending and the reflecting electrodes and a pure reactance element connected to the junction between the two serially connected reactance elements so as to form a T-circuit. When the two serially connected pure reactance elements are selected equal to each other, the operating frequency band is broadened. The phase shifter includes no ohmic resistance and thus is lossless.
摘要:
An elastic surface wave device that has good frequency characteristics and no unwanted signals, and is highly suited for mass production, comprising a piezoelectric substrate, at least one pair of transmitting and receiving electrodes on the surface of said substrate, and elastic surface wave absorbers formed by curing a composition, the main component of which is a resin curable by ultraviolet radiation, disposed on at least part of the zone on said piezoelectric substrate that propagates unwanted elastic surface waves.
摘要:
A structure of a spectrum spreading communication device which solves the problem with the conventional spectrum spreading communication using Barker codes, etc., and limits the rise of the side-lobe of a correctional signal independently of the order of information codes by use of a code sequence having a code length of at least 14. The spectrum spreading communication device uses a pseudo-noise code having code length of at least 14 and a self-correlation side-lobe of not greater than 3 as a pseudo-noise code of a direct spreading communication device which uses the pseudo-noise codes whose polarities are inverted so as to deal with also digital information. Thus, even when the pseudo-noise code length is 14 or more, the side-lobe of the correction coefficient can be restricted. Accordingly, the error rate of the spectrum spreading communication device is reduced and the processing gain is improved.
摘要:
A surface-acoustic-wave filter for a channel selection tuning system of a television receiver includes at least two comb filter elements, each of which comprises an input transducer provided on a piezoelectric substrate and adapted to convert an input electrical signal into an elastic surface wave, and first and second output transducers disposed on the substrate for receiving the elastic surface wave propagating in the same direction from the input transducer. The first and second output transducers are positioned from the input transducer with different distances. The transducers of the two comb filter elements are so designed that the respective comb filter elements respond to frequencies of different program channel bands over for example VHF and UHF bands. The distances of the first and the second output transducers from the input transducer in the wave propagating direction are so predetermined that reciprocal of the difference in delay time between the electrical signals derived from the first and second output transducers is equal to a divisor of an interchannel frequency difference in the corresponding channel band.