Abstract: A monolithic circuit, such as a piezoelectric device, semiconductor, or the like, may be fabricated by forming an operational metallization layer (12) on a substrate (10). A subsequent layer (40), such as a sealing ring pattern (42) may then be applied using a thin film deposition technique. A thin film material is applied through a mask assembly (28). The mask assembly (28) includes a mask material (30) that has been applied to a screen (24) and patterned as desired. The mask material (30) extends beyond the screen (24) so that only the mask material contacts the substrate (10) during thin film deposition. Preferably, the screen (24) is woven from individual wires (26) having circular cross-sectional shapes. The subsequent layer (40) is applied both through perforations (18) in the screen (24) and under the screen's wires (26).

Abstract: An apparatus comprises a first and a second input and a processor coupled to the inputs. The processor estimates peak and minimum levels of each of the first and second input signals. A first signal regulator is coupled to the first input and to a first output for delivering a first output signal from the first signals. A second signal regulator is coupled to the second input and to a second output for delivering a second output signal from the second audio signals. A gain adjustment device is coupled to the processor and the first and second signal regulators. The gain adjustment device provides control signals to the first and second signal regulators to adjust an output signal level of the first output signal in response to minimum and peak levels of the first and second input signals. The output signal level is continuously variable over a range.

Abstract: A method of soldering without the use of flux, wherein a plurality of solder bumps are deposited on a first surface and a plurality of solder pad locations are prepared on a second surface. The first and second surfaces are placed immediately adjacent to one another, placing each the plurality of solder bumps in the proximity of a corresponding solder pad location on the second surface. The first surface, the second surface and the solder are placed in a chamber which is evacuated to a low pressure. A plasma is excited within the chamber which heats the first and the second surfaces, thereby heating the plurality of solder bumps and the plurality of solder pad locations by heat conduction and reflowing the plurality of solder bumps on the first surface and on the plurality of solder pad locations on the second surface to form a plurality of solder bonds therebetween.

Abstract: A high voltage semiconductor structure (10) includes a semiconductor substrate (11) of a first conductivity type. The structure (10) also includes a first region (12) providing a main rectifying junction, a second region (13, 17, 21) of a second conductivity type formed in the semiconductor substrate and surrounding the first region ( 12 ) and a third region (14, 18, 22) of the second conductivity type. The third region (14, 18, 22) has reduced conductivity and greater junction depth compared to the second region (13, 17, 21). The third region (14, 18, 22) surrounds and is in contact with the second region (13, 17, 21) to form field rings which improve (increase) breakdown voltage of the high voltage semiconductor structure (10).

Abstract: A distributed communication network includes switching offices (SOs), moving-orbit satellites, and subscriber information managers (SIMs). A population of mobile units (MUs) communicates through the network. A MU automatically determines its location and communicates with the network so that this information is kept current at a SO serving the MU and at a home SIM for the MU. The terrestrial nodes of the network have information showing which MUs are logged on at any given time. This knowledge is used to block calls to MUs known to be logged off. Calls are setup through cooperation between SOs. When calls are being setup to MUs, call-originating SOs determine appropriate SIMs and obtains the current location of the MUs from those SIMs. This current location corresponds to a call-destination SO with which the originating SO may cooperate in setting up a call.

Abstract: An apparatus for secure communications contains a controller for automatically selecting one of several data ciphering devices utilizing one of a plurality of ciphering algorithms common to transmitting and receiving terminals. A transmitter for transmitting encrypted data, and a receiver for receiving encrypted data are coupled to the plurality of ciphering devices. The controller automatically determines which of the ciphering devices to employ for any given secure communication. The method for establishing a secure communications link includes the steps of exchanging a first message for determining a common key generation and ciphering method and comparing a further shared message for validation of communications terminal security.

Abstract: A method for establishing a secure communications link between first and second terminals includes a step of exchanging a first message. The first message contains information describing encryption devices and communications modes available within the terminals and user authentication information. The method also includes a step of selecting, in at least one terminal, a common key generation and ciphering algorithm. The method further includes steps of exchanging a second message for providing data to form traffic keys, exchanging a third message for synchronizing secure communications and initiating secure communication.

Abstract: A sample and hold circuit is formed within an integrated circuit and has a small, substantially linear hold capacitance. The circuit includes a sampling switch, a hold capacitor, and a buffer amplifier. The buffer amplifier includes a common drain FET and a constant current source FET. The common drain FET provides an input which couples to the hold capacitor. The constant current FET isolates the source of the common drain FET from ground. The sample and hold circuit may be used as a wide bandwidth mixer. In a radio application, a pulse generator provides a stream of pulses in which the sampling rate times an integer number equals the RF frequency minus the IF frequency. The width of the sampling pulse is less than the period of an RF signal. In an oscillator application, the sample and hold circuit operates as a mixer in a frequency multiplying phase locked loop.

Abstract: A signal mixing apparatus comprising first and second four port signal splitting/combining networks having no relative phase shift between three ports and 180.degree. of phase shift between the remaining ports, coupled to a four port mixer element. The mixer element has two ports coupled to the first signal splitter/combiner network and having another two ports coupled to the second splitter/combiner, RF and LO signals input to the first splitter/combiner do not appear at the IF output from the second splitter/combiner or vice versa. The RF/IF signals cancel and the LO signal is trapped by a resonant circuit within the mixer. The RF and IF frequency bands may overlap.

Abstract: A method for insulating metal powder particles comprises steps of placing the metal powder particles in a mixing container and adding a monomer in solution to the metal powder particles to form a mixture. The mixture is then stirred to provide an even consistency and is baked to remove solvents. The mixture is then stirred and the monomer is polymerized by exposing the monomer coated carbonyl iron particles to moist gas. The mixture is then ground to form a powder. The powder is suitable for incorporation into plastic resins for subsequent casting to form radio frequency shields having high DC resistance.

Abstract: A filter device comprises an acoustic wave propagating substrate having an effective coupling coefficient k.sup.2 and having a first filter and a second filter disposed on the acoustic wave propagating substrate. The first filter comprises a first electro-acoustic transducer and a first acousto-electric transducer, both disposed on the acoustic wave propagating substrate. The first acousto-electric transducer comprises N.sub.1 many electrode pairs, wherein N.sub.1 .gtoreq.C/k.sup.2. C is a constant having a value in the range from 1 to 2. The first acousto-electric transducer is acoustically coupled to the first electro-acoustic transducer. The second filter comprises a second electro-acoustic transducer and a second acousto-electric transducer, both disposed on the acoustic wave propagating substrate. The second electro-acoustic transducer is electrically coupled to the first acousto-electric transducer. The second electro-acoustic transducer comprises N.sub.2 many electrode pairs, wherein N.sub.2 <C/k.

Abstract: A method for passing supervisory control from a first station to a second station of a plurality of stations comprises steps of providing a message header in interstation messages in the first station, transmitting the interstation message from the first station to the second station, processing a message header from the interstation message to extract data and determining present identification of a system controller from the extracted data. The method includes steps of providing a first field containing message identification information, providing a second field containing supervisor station identification information, providing a third field containing update count information and providing a fourth field containing sending station identification information in the message header.

Abstract: A reflector arrangement for an acoustic wave device comprises an acoustic wave propagating substrate, reflection elements having at least two different widths separated by at least one gap breadth disposed on the acoustic wave propagating substrate. The at least two different widths enhance reflected waves produced by the propagating acoustic wave in such a fashion as to achieve a total acoustic reflectivity which is independent of variations in width of the reflection elements.

Abstract: A low-loss acoustic wave filter includes a piezoelectric substrate, a first strongly unidirectional acoustic wave transducer and a second strongly unidirectional acoustic wave transducer. Each of the first and second strongly unidirectional acoustic wave transducers are acoustically coupled to one another. Each of the first and second strongly unidirectional acoustic wave transducers further comprises an acoustic wave reflector and a weakly unidirectional acoustic wave transducer. The acoustic wave reflector and the weakly unidirectional acoustic wave transducer are coupled to the piezoelectric substrate.

Abstract: An electronic apparatus for receiving and filtering high frequency waves comprises a sequence of T electroacoustic transducers each having multiple interdigital electrode fingers and a centerline located equidistant between its outermost electrode fingers. For a centerline-to-centerline distance of a first adjacent pair of transducers D.sub.1, and centerline-to-centerline distances of other adjacent pairs of transducers D.sub.2 to D.sub.T-1, then at least some of D.sub.2 to D.sub.T-1 differ from D.sub.1 by a non-integral number of wavelengths. The transducer array is symmetrical about a centerline and the number of fingers in each transducer varies, with an input or output transducer closer to either end of the sequence having more fingers than a like kind transducer nearer the center.

Abstract: A multi-channel receiver automatically determines the noise floor of each channel and resets the channel threshold based thereon while avoiding undesirable bias from weak non-noise signals. The power probability of uncharacterized input signals (non-noise content unknown) is computed and normalized to have a known probability that the power exceeds a first threshold. A second probability of exceeding a second threshold is determined and compared to a predetermined reference probability for a noise-only signal at the same threshold. If the computed second probability is not higher than the reference probability, then the uncharacterized signal is a noise only signal whose average is the noise floor for the channel. The threshold detection level is then set a predetermined amount above the noise floor. The process is automatic and compensates for receiver aging and ambient noise fluctuations with time and from channel to channel and for other changes.

Abstract: A package for a frequency selection component includes a base, a thermoplastic die attachment, and either a soldered or low- melting-temperature glass lid attachment. These techniques can be employed in either a leadless chip carrier or a single layer ceramic base configuration. A package for a surface acoustic wave device in accordance with one embodiment of the invention is suitable for enclosing the device in a hermetically sealed environment such that the resulting structure takes up a minimum volume of space. The package facilitates automated circuit assembly techniques, allowing compact, low cost products to incorporate frequency selection components when these are made in accordance with the present invention.

Abstract: A method and apparatus for improved isolation of IF, LO, and RF frequency signals from the non-associated mixer ports (e.g., avoiding introducing RF frequency signals at the IF and LO ports, and similarly vis-a-vis other signals and ports), is provided by coupling a RF (or LO) signal to first ports of four-port first and second phase shift means, each having two signal output ports having 180.degree. phase difference for signals input from the first port, coupling the LO (or RF) signal to the first port of a third phase shift means, with two output signal ports having a phase difference of 180.degree., supplying the third phase shift means output signals to fourth ports of the first and second phase shift means, supplying the output signals of the first and second phase shift means to distinct ports of a five port mixer, and coupling an IF signal from the five port mixer to an IF port.

Abstract: A communication system service billing arrangement is described that adapts to system loading in realtime. As system loading varies, one or more individual subscribers units (ISU) of a communication system are provided with realtime information on the current cost of the communication service. The system determines the locations of the ISUs and the current loading there between and calculates a calling rate based at least on the current loading. This calling rate is sent to at least one of the ISUs whose operator can choose to connect or not connect the call between the ISUs based on the current realtime variable rate.

Abstract: A method for making a light weight circuit module includes steps of providing a substrate, drilling through holes in the substrate and plating the through holes with a metal. The substrate is a rigid planar substrate and having metallization on both sides. The method also includes steps of drilling through holes in the substrate and plating the through holes with a metal. The method also includes steps of preparing a patterned photoresist layer on at least one of the two sides, etching the metallization on the at least one side in accordance with the patterned photoresist layer, drilling support holes, filling the support holes with a material chemically distinct from the substrate, stripping the patterned photoresist layer from the at least one side and chemically removing the substrate from the metallization.