Abstract: A system includes a database, a controller, and multiple nodes. The database is capable of storing information. The controller is capable of facilitating access to the database. The controller is also capable of detecting a new node in the network and, if necessary, communicating a network protocol to the new node to allow the new node to participate in the network. The information in the database could represent medical-related information. The nodes could include fixed nodes and portable nodes. The network could represent a mesh network.

Abstract: A vehicle back-up alarm system includes a sensor capable of determining when a vehicle is at least one of in a reverse gear and moving backwards. The vehicle back-up alarm system also includes a transmitter module capable of transmitting a warning signal in response to the sensor determining that the vehicle is at least one of in the reverse gear and moving backwards.

Abstract: An asset subsystem is provided for use in a security system. The security system includes a security system controller operable to trigger an alarm. The asset subsystem includes a transceiver operable to communicate a first signal to a tag associated with an asset and to receive a second signal communicated by the tag in response to the first signal. The asset subsystem also includes a controller operable to determine whether the tag failed to communicate the second signal to the transceiver and trigger the alarm in response to determining that the tag failed to communicate the second signal to the transceiver.

Abstract: A method includes receiving a wireless warning signal. The method also includes identifying a type of warning associated with the wireless warning signal. In addition, the method includes generating at least one stimulus based on the identified type of warning and capable of being detected by a user. As particular examples, the at least one stimulus includes visual and/or tactile stimuli that differ based on the identified type of warning. The visual stimuli may be produced by a stimulator on a hardhat worn by the user. The tactile stimuli may be produced by a stimulator in a wristband worn by the user.

Abstract: A circuit includes one or more first amplifiers operable to amplify an incoming signal to produce an amplified incoming signal. The incoming signal is associated with a desired signal. The circuit also includes a controller. In response to the amplified incoming signal exceeding a first threshold and the desired signal not exceeding a second threshold, the controller is operable to allow one or more second amplifiers to amplify the incoming signal and/or increase a current supplied to the one or more first amplifiers.

Abstract: A frequency agile sequential amplifier circuit that includes first and second RF amplifiers coupled by a SAW delay line, a double balanced mixer coupling the first RF amplifier to the SAW delay line, the output of the first RF amplifier providing a signal as a first input to the double balanced mixer and a variable pulse generator coupled to both said first and second RF amplifiers to cause them to sequentially and alternately conduct, and a divide/2 circuit coupling said variable pulse generator to said double balanced mixer as a second input at ½ the rate of said RF amplifiers to cause the sequential amplifier circuit to achieve frequency agility and to substantially maintain its sensitivity.

Abstract: There is disclosed a SAW resonator-based oscillator circuit having low phase noise that is tunable across a comparatively wide frequency range. The oscillator circuit comprises: 1) a tuning element coupled to the input port and having a variable capacitance responsive to the frequency tuning signal; 2) a first inductor coupled in series with the tuning element; 3) a SAW resonator coupled in series with first inductor; 4) a second inductor coupled in parallel with the SAW resonator; 5) a negative resistance generating circuit coupled to the SAW resonator. Across the tunable operating frequency range of the oscillator circuit, the reactance looking into the input port is maintained at approximately zero and the resistance looking into the input port remains negative.

Abstract: A method of attaching a lid with at least a metallic surface thereon to a substrate to enclose a surface acoustic wave electronic circuit using a fluxless solder preform having an undesired oxide surface and associated with the metallic surface on the lid and in superimposed and abutting relationship with a gold seal ring surrounding the electronic circuit to form a unit that is heated in a furnace having a hydrogen atmosphere such that the hydrogen removes any undesired oxide surfaces from the solder preform and the metallic surface on the lid by combining with the oxygen therein to form moisture so as to remove any oxide surfaces from the solder preform and the lid metallic surface and enable a complete bonding of the fluxless solder preform with the gold seal ring and the lid metallic surface thereby forming a hermetically sealed package.

Abstract: There is disclosed a SAW resonator-based oscillator circuit having low phase noise that is tunable across a comparatively wide frequency range. The oscillator circuit comprises: 1) a tuning element coupled to the input port and having a variable capacitance responsive to the frequency tuning signal; 2) a first inductor coupled in series with the tuning element; 3) a SAW resonator coupled in series with first inductor; 4) a second inductor coupled in parallel with the SAW resonator; 5) a negative resistance generating circuit coupled to the SAW resonator. Across the tunable operating frequency range of the oscillator circuit, the reactance looking into the input port is maintained at approximately zero and the resistance looking into the input port remains negative.

Abstract: A method of attaching a lid with at least a metallic surface thereon to a substrate to enclose a surface acoustic wave electronic circuit using a fluxless solder preform having an undesired oxide surface and associated with the metallic surface on the lid and in superimposed and abutting relationship with a gold seal ring surrounding the electronic circuit to form a unit that is heated in a furnace having a hydrogen atmosphere such that the hydrogen removes any undesired oxide surfaces from the solder preform and the metallic surface on the lid by combining with the oxygen therein to form moisture so as to remove any oxide surfaces from the solder preform and the lid metallic surface and enable a complete bonding of the fluxless solder preform with the gold seal ring and the lid metallic surface thereby forming a hermetically sealed package.

Abstract: A digitally-controlled SAW stabilized FSK oscillator circuit having an oscillator and a single-port SAW resonator with a predetermined circuit resonant frequency and being coupled to the oscillator for establishing a first oscillator output frequency, F.sub.SAW. A bipolar transistor has at least one predetermined shunt capacitance value, C, that is placed in electrical series with the single-port SAW resonator when the transistor is in the OFF state and a closed switch that replaces the capacitance when the transistor is in the ON state to cause the first frequency, F.sub.SAW, to be generated by the oscillator when the transistor is ON and to cause a second frequency, F.sub.2, to be generated by the oscillator when the transistor is in the OFF state.

Abstract: An improved surface acoustic wave device that utilizes M electrodes per each N transduction length(s) of a transducer that produces a desired net internal distributed reflectivity in both magnitude and phase. Two of the transducers can be made placed on a single substrate and be unidirectional and caused to radiate towards each other to form a filter. A resonator, a delay line, or the like can also be formed.

Abstract: A crystal-controlled oscillator circuit is modified by the present invention by replacing the crystal with the first signal port of a two-port SAW resonator filter that has a low-loss primarily inductive characteristic and taking the oscillation output from the other port of the filter to provide an oscillator frequency with harmonics that are reduced significantly when compared to the output of a crystal-controlled oscillator.

Abstract: A transceiver including a receiver having a sequential amplifier that includes at least first and second RF amplifier stages coupled together by a delay line. A transmitter in the transceiver includes an oscillator for generating an RF carrier and the oscillator includes the delay line as a phase shifting element. A modulator is coupled to the oscillator for modulating the RF carrier either AM, OOK modulated, FM, FSK modulated, PM, and PSK modulated.

Abstract: A low-power, self-quenching superregenerative receiver utilizes a single-port SAW device coupled to an RF oscillator to establish the frequency of oscillation at the output of the RF oscillator. A diode detector is coupled from the oscillator output for detecting a predetermined amplitude of the oscillation output signal. A time-constant circuit is coupled from the signal detector for generating an oscillator quench signal when the oscillator signal is detected and the oscillator quench signal has a predetermined duration set by the time-constant circuit. A feedback circuit couples the oscillator quench signal to the RF oscillator to cause the RF oscillator to switch to a non-oscillating condition only during the predetermined duration of the RF oscillator quench signal. The RF oscillator then switches to the oscillating condition and the system repeats itself.

Abstract: A high stability clock oscillator circuit that has no inductors in the oscillator circuit itself. In the preferred embodiment neither the collector, the base, nor the emitter of the transistor is grounded and the oscillator output is taken from the collector of the transistor. In an alternate embodiment the collector is AC grounded and the output is taken across a load resistor coupled between the emitter of the transistor and ground. The resulting oscillator is a high stability oscillator that can be used as a dock oscillator in high frequency circuits.

Abstract: An acoustic wave device in which the propagation path of the surface acoustic wave device is folded to increase the wave propagation path length in order to make better use of the total chip space.

Abstract: An RF signal amplifier comprising a single stage of amplification coupled through a first switch to the input of a SAW delay line and, after the SAW delay line is charged, through a second switch to the input RF amplifier for second amplification with the output of the RF amplifier being coupled through said first switch to an output terminal.

Abstract: A novel surface acoustic wave device that includes a multiple track transducer having a first portion for generating a transverse symmetrical mode acoustic wave and a second portion for receiving only a transverse nonsymmetrical surface acoustic wave such that substantially no direct coupling occurs between the first and second portions of the multiple track transducer and where reflector gratings are mode changing gratings that reflect the transverse symmetrical wave as a transverse nonsymmetrical wave that is received by the second portion of the multiple track transducer thereby substantially reducing undesired in-band surface acoustic wave transducer responses as well as spurious bulk responses and allowing a narrow passband to be obtained with a short structure when compared with the prior art structures.

Abstract: An improved surface acoustic wave grating structure that utilizes four electrodes per 3.lambda./2 or 5.lambda./2 transduction length of a reflector grating structure that produces a desired net internal distributed reflectivity in both magnitude and phase.