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Patent

Method and means for coupling a multiplicity of surface acoustic wave transducers to a single electromagnetic wave transmission line

TLDR
In this paper, the inductance value of the inductor was chosen such that minimum transducer insertion loss is achieved at the center frequency of the midband channel, subject to the constraint that the insertion losses of all the remaining channels, measured at their respective center frequencies, lie at or near the above optimum value within an acceptable prespecified margin.
Abstract
The input transducers of a multichannel surface acoustic wave device are electrically connected in a series or series-parallel circuit arrangement and are connected to a single channel electromagnetic wave transmission line through an inductor. The inductance value of the inductor is chosen such that minimum transducer insertion loss is achieved at the center frequency of the midband channel. The circuit arrangement is selected which achieves optimum coupling to the midband channel subject to the constraint that the insertion losses of all the remaining channels, measured at their respective center frequencies, lie at or near the above optimum value within an acceptable prespecified margin.

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Citations
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Low loss wide bandwidth parallel channel acoustic filter

TL;DR: An acoustic wave filtering apparatus includes an acoustic wave propagating substrate for supporting propagation of acoustic waves and a plurality of acoustic wave filters for filtering an electrical signal as discussed by the authors, each of said plurality further comprises an input for supplying electrical input signals, an input unidirectional acoustic wave transducer for converting electrical signal energy into acoustic energy, an output unIDirectional audio wave transducers for converting acoustic signals to electrical signals, and an output for combining and delivering electrical output signals to external electrical apparatus.
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TL;DR: In this paper, a monolithic lattice SAW bandpass filter with low insertion loss and a wide bandwidth range is described, where the SAW devices are coupled in a cascaded circuit configuration such that no electrical crossovers occur on the substrate.
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Communication Systems Using Passive RF Routing

TL;DR: In this paper, the authors propose a demultiplexer-multiplexer (DM-M) for the communication between an upstream point, such as a TV-source headend followed by a fiber optic line, and a number of downstream points such as coaxial cable connected subscriber locations.
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High power acoustic wave arrangement with N2 parallel-series connected acoustic wave devices

TL;DR: In this paper, the authors proposed a parallel-series arrangement of N 2 acoustic wave devices (A,B,S,T; where T is an integer greater than unity) with substantially the same electrical impedance and transfer characteristics at a given operating frequency, but an increased active device area.
References
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Patent

Surface wave frequency discriminator

P Hartemann
TL;DR: In this paper, a pair of surface wave electromechanical filters are placed upon a single substrate, and the spectral responses of the filters are offset in frequency and have a triangular profile so that by subtraction of the detected voltages at the output of these filters, an S characteristic is obtained.
Patent

Selectable frequency bandpass filter

Hartmann C
TL;DR: In this paper, a selectable frequency bandpass filter includes a set of electrical filters with each of which is associated with a switch, and a subset of the electrical filters is connected in parallel between the input and the output of the selectable filter.
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Surface wave frequency discriminators

TL;DR: In this article, a plurality of interdigitated surface wave transducers are formed on a piezoelectric substrate along a common acoustic channel and the signal from the output transducers is rectified and then filtered to separate the r.f. component from the audio signal.
Patent

Acoustic delay line