摘要:
A thin-film bulk acoustic wave delay line device providing true-time delays and a method of fabricating same. An exemplary device can comprise several thin-film layers including thin-film transducer layers, thin-film delay layers, and stacks of additional thin-film materials providing acoustic reflectors and matching networks. The layer material selection and layer thicknesses can be controlled to improve impedance matching between transducers and the various delay line materials. For example, the transducer layers and delay layers can comprise piezoelectric and amorphous forms of the same material. The layers can be deposited on a carrier substrate using standard techniques. The device can be configured so that mechanical waves propagate solely within the thin films, providing a substrate-independent device. The device, so constructed, can be of a small size, e.g. 40 μm per side, and capable of handling high power levels, potentially up to 20 dBm, with low insertion loss of approximately 3 dB.
摘要:
A mode converter for a distance measuring device having a sonic delay line with a permanent magnet movable along same, the converter having a free-standing magnetostrictive armature with one end attached to the delay line and the other end terminating dampinglessly within the usual coil. The armature length and shape are such that the longitudinal stress wave initiated by an electrical pulse in the coil strengthens the mechanical pulse applied to the delay line.
摘要:
A length dependent, optical time delay/filter device for electrical signals having a single integrated optical switching circuit and only two optical time delay components connected thereto. The optical time delay components are each made up of a plurality of optical fibers of varying lengths. Depending upon which fibers an optical signal (converted from an incoming electrical signal) passes through determines the time of travel of the optical signal through the device. This optical signal is then converted back into an electrical output signal which is, as a result thereof, time delayed/filtered.
摘要:
A body of lithium niobate coated with a first thin layer of magnesium and a second conductive metal layer on the magnesium layer permits subsequent ultrasonic bonding of a wire to the second layer without problems of delamination.
摘要:
In a broadband microwave acoustic delay line, two or more transducers are used for energy translation from electromagnetic into acoustic (one type) and reverse (the other type) which are mechanically independent and resonant at acoustic frequencies different from one to the others. Each transducer of one type is connected to a first end of a matching section which constitutes a series resonant circuit tuned at a frequency within the band different from the frequency corresponding to any other transducer. The second ends of the two or more matching sections are connected at the same end of a wideband impedance transformer.
摘要:
An electrical signal transmission device such as a delay line or filter of the acoustic, reflection mode type wherein an input electrical signal is converted to acoustic energy propagating along a medium such as a thin rectangular strip of spring steel toward a mismatching structure such as an array of gratings which reflects a portion of the energy for further propagation and conversion to an output electrical signal. The phase response of the device is shaped or compensated by a region of phase affecting material, such as a thin mass-loading film of gold or similar material, located on the propagating medium in the path of the reflected signal. A pattern or profile generated from the measured phase response of the device is used to control application of the material, preferably by vapor deposition, the profile and thickness of the region or film being predetermined to shape the phase response without affecting the amplitude response.