摘要:
A thin film metallic loop (30) is used to electrically short the gap (16a) between metallic portions (16, 28) of a surface acoustic wave device (10) to eliminate substrate surface cracks. The loop (30) is deposited on the substrate (13) at the same time the structures (16, 28) defining the gap (16a) are deposited.
摘要:
A surface acoustic wave device is provided with at least two exciting electrodes 2 and 3 for exciting first and second surface acoustic waves on a piezoelectric substrate 1, a surface acoustic wave waveguide 4 for propagating therethrough the first and second surface acoustic waves excited by the exciting electrodes in opposite directions, output means 5 for taking out a signal generated by the surface acoustic wave waveguide 4, and an electrode junction portion 6 electrically connecting the surface acoustic wave waveguide and the output means together, and is characterized in that the width of a portion in which the electrode junction portion 6 is in contact with the surface acoustic wave waveguide 4 is within a range of 0.2 to 5 times the wavelength of the first and second surface acoustic waves.
摘要:
An elastic surface wave convolver comprises a piezoelectric substrate, a plurality of input transducers formed on said substrate for generating elastic surface waves corresponding to respective input signals, a plurality of waveguides provided side by side on a region of the substrate where elastic surface waves radiated from the input transducers overlap, wherein a convolution signal of input signals is produced due to parametric mixing effect of elastic surface waves in respective waveguides, these waveguides generating an elastic surface wave corresponding to the convolution signal, and an output transducer for receiving the elastic surface wave radiated from the waveguides and taking out an electrical signal by conversion of the convolution signal, wherein the width of elastic surface wave radiated from the waveguides is narrower immediately before reception with the output transducer than immediately after radiation from the waveguides.
摘要:
Für einen mit einem Eingangssignal E und mit zwei Referenzsignalen R₁ und R₂ zu betreibenden Convolver (Fig. 1) sind zwei Convolver-Spuren (bzw. vier Spuren bei Kompensation der Selbstfaltung) mit gegenüber dem Eingangswandlern 5 und 6 für die Referenzsignale R₁ und R₂ (bzw. vier) parallelgeschalteten Eingangswandlern 3, 4 (bzw. 3, 1; 3, 2; 4, 1; 4, 2) für das Eingangssignal E erforderlich. Damit bei an allen 3 Eingängen des Convolvers mit derselben Eingangsimpedanz alle Eingangswandler 3, 4, 5, 6 dennoch prizipiell demselben Entwurf entsprechen, sind für die Eingangssignal-Wandler 3, 4 abgewandelte Splitfinger-Wandler (Fig. 3, Fig. 4) mit floatenden Fingern (und die nicht abgewandelten Splitfingerwandler (Fig. 2) für die Referenzsignale) vorgesehen.
摘要:
Zweispur-Convoler mit seriell integrierten Einzelwandlern (4a, 4b; l4a, l4b) als Eingangswandler (4, l4) für das Eingangssignal und das Referenzsignal, um für vorgegebene Eingangsimpedanz solche Einzelwandler verwenden zu können, die möglichst große Chirpdauer (große Länge der Einzelwander) ermöglichen.
摘要:
Traitement de signal par un système comportant un dispositif à ondes élastiques, invariant en température. Le signal d'entrée Se est inscrit dans une mémoire (23) à la cadence d'une horloge fixe h E et lue à la cadence d'une horloge H L fourni par un générateur asservi, qui fournit également les signaux notamment de mise sur porteuse (H 2o ) à un circuit d'interface (25). Le signal est appliqué à un dispositif à ondes élastiques (21) qui fournit un signal traité S 3 appliqué à un second circuit d'interface (26) et à une seconde mémoire (27). Le générateur asservi fournit également les signaux de démodulation au second circuit d'interface (26) et les signaux d'horloge d'écriture H E de la seconde mémoire (27), qui est lue à la cadence d'horloge fixe h L . Le générateur asservi comporte un pilote de base formé d'un oscillateur à ondes élastiques de surface réalisé avec le même substrat que celui du dispositif de traitement à ondes élastiques. Application à la compression d'impulsions, à l'analyse spectrale et aux convoluteurs à ondes élastiques.
摘要:
A surface acoustic wave functional element is provided with a semiconductor layer on a piezoelectric substrate or piezoelectric thin film substrate and utilizes the interaction between surface acoustic waves propagated on the surface of the substrate and electrons in the semiconductor layer. The semiconductor layer is formed outside the propagating path of the surface acoustic waves and provided with a plurality of grating electrodes perpendicularly to the propagating path, an active layer, and a buffer layer lattice-matched with the active layer. Using this surface acoustic wave functional device, a surface acoustic wave amplifier with a high amplification degree at a practical low voltage is provided, and a surface acoustic wave convolver having such a high efficiency that has not been achieved so far, is provided.