摘要:
At least one electro-acoustic transducer of a first surface acoustic wave device and acousto-electric transducers of a second surface acoustic wave device are arranged symmetrically to the first surface acoustic wave device about a line parallel to a propagating direction of surface acoustic wave and is phase-weighted differently from the remaining transducers having common phase-weighting, to improve an attenuation for stop frequency.
摘要:
Disclosed is a SAW filter employing a SAW resonator which is constructed of a plurality of pairs of electrode fingers formed on a piezoelectric substrate, and in which a plurality of SAW transmission spaces are included. The SAW transmission spaces do not have the function of exciting a SAW, and they have electric lengths which match the phases of SAWs excited by the resonator. In accordance with frequency characteristics required of the filter, such SAW transmission spaces are introduced into, for example, one of a plurality of SAW resonators located on the electric power input side of the filter.
摘要:
A surface acoustic wave device comprises a piezoelectric substrate and a plurality of electrode fingers which are located on the piezoelectric substrate along the propagation direction of a surface acoustic wave. The electrode fingers are located on the piezoelectric substrate at a pitch of about 1.5.lambda.o/2 (where a symbol .lambda.o indicates a wavelength of a surface acoustic wave with a frequency equivalent to the center frequency of the surface acoustic wave device). The width of each of the electrode fingers is about 1.5.lambda.o/4. The electrode fingers are located on the substrate so as to be electrically independent of an external circuit and each other.Since the width of electrode fingers is about 1.5.lambda.o/4, the surface acoustic wave device can be produced without fine processing techniques.
摘要:
A surface acoustic wave device comprises a piezoelectric substrate and a plurality of electrode fingers which are located on the piezoelectric substrate along the progagation direction of a surface acoustic wave. The electrode fingers are located on the piezoelectric substrate at a pitch of about 1.5.lambda.o/2 (where a symbol .lambda.o indicates a wavelength of a surface acoustic wave with a frequency equivalent to the center frequency of the surface acoustic wave device). The width of each of the electrode fingers is about 1.5.lambda.o/4. The electrode fingers are located on the substrate so as to be electrically independent of an external circuit and each other.Since the width of electrode fingers is about 1.5.lambda.o/4, the surface acoustic wave device can be produced without fine processing techniques.
摘要:
A surface acoustic wave device is disclosed for use in a communication apparatus where the surface acoustic wave device has a multiple of surface acoustic wave elements with different filter characteristics formed on mutually distinct piezoelectric substrates. The different filter characteristics combine to form filters having desired filter characteristics.
摘要:
In a high frequency circuit device, inductive circuit elements constituting a matching circuit are constructed of so-called helical coils having fine metal wires wound in a hollow solenoid form, which are disposed inside a package in which a high frequency circuit element such as a surface acoustic wave element or the like is mounted. The high frequency circuit device may be utilized in equipment such as wireless communication equipment for reducing the size as well as providing good high frequency characteristics.
摘要:
A high frequency module is disclosed which comprises a high frequency device in a package, a circuit formed on a flexible substrate in the package, the circuit, the high frequency device and input/output terminals of the package being connected electrically.
摘要:
A SAW resonator includes resonating SAW transducer units formed on a piezoelectric substrate and juxtaposed in a direction of propagation of acoustic waves, and a unidirectionally reflecting SAW transducer unit provided in each end of the juxtaposed resonating SAW transducer units on the substrate. Each resonating SAW transducer unit includes first and second SAW transducers connected in series and/or in parallel with each other. Each unidirectionally reflecting SAW transducer unit includes first and second comb-like electrodes having a plurality of first second fingers, respectively, formed on the substrate, in which: two second fingers are interposed between each pair of adjacent two first fingers; at least one reflective stripe is provided between the two second fingers interposed between at least one pair of adjacent two first fingers; and the distances between the reflective stripe and the two second fingers and the widths of the two second fingers are determined such that acoustic waves produced by the fingers of the reflecting SAW transducer units and propagating in a first direction perpendicular to the direction of the length of the fingers and reflected by the reflective stripe in a second direction perpendicular to the first direction are in phase with acoustic waves propagating in the second direction and acoustic waves produced by the fingers of the reflecting SAW transducer units and propagating in the second direction and reflected by the reflective stripe in the first direction are out of phase with acoustic waves propagating in the first direction.
摘要:
A surface acoustic wave device has its inter--digital transducers made of a 3--metal alloyed material consisting of aluminum, copper and magnesium.
摘要:
A piezoelectric thin film resonator is formed on a base substrate such as made of Si in which the resonance frequency is substantially determined by the lateral size not by the thickness of the resonator, whereby a resonator for use in TCXO, etc. is provided by the thin film technique, which enables to reduce the thickness of the film and the size of the resonator and integration with Si-based IC incorporating the resonator in one identical substrate.