Abstract: An apparatus includes a frequency counter configured to receive an input signal containing pulses and to output a count value identifying a number of pulses in the input signal during a specified time period. The specified time period encompasses multiple cycles of the input signal. The apparatus also includes a comparator configured to receive the count value, compare the count value to a second value, and provide an output signal based on the comparison. The apparatus further includes a data latch configured to latch the output signal, where the latched value of the output signal represents a demodulated data value. The comparator could be configured to compare the count value to a fixed value associated with a desired frequency of the input signal. The comparator could also be configured to compare the count value in one specified time period to a stored count value from another specified time period.

Abstract: An apparatus includes a first oscillator configured to generate a reference signal and a second oscillator configured to generate an output signal having a controllable frequency. The apparatus also includes a frequency difference detector configured to generate a difference signal having a frequency based on a frequency difference between the reference signal and the output signal. The apparatus further includes a discriminator configured to modify the frequency of the output signal based on the difference signal. The frequency difference detector can be configured to generate the difference signal having multiple pulses. The discriminator can be configured to count a number of pulses in the difference signal during a specified time period and to modify the frequency of the output signal based on the counted number of pulses. The specified time period can be adjustable.

Abstract: An apparatus includes a first oscillator configured to generate a reference signal and a second oscillator configured to generate an output signal having a controllable frequency. The apparatus also includes a frequency difference detector configured to generate a difference signal having a frequency based on a frequency difference between the reference signal and the output signal. The apparatus further includes a discriminator configured to modify the frequency of the output signal based on the difference signal. The frequency difference detector can be configured to generate the difference signal having multiple pulses. The discriminator can be configured to count a number of pulses in the difference signal during a specified time period and to modify the frequency of the output signal based on the counted number of pulses. The specified time period can be adjustable.

Abstract: A method includes receiving a first message at a router in a mesh network and synchronizing the router to a plurality of time slots using the first message. The method also includes repeatedly incrementing a network reference value at each time slot up to a maximum value and then decrementing the network reference value at each time slot down to a minimum value. In addition, the method includes broadcasting a second message at the router when the network reference value has a specific value that is associated with a unique identifier of the router.

Abstract: A method includes receiving a request to identify any communication paths visible to a first router in a mesh network and broadcasting the request. The method also includes identifying one or more second routers that broadcast information received by the first router, where the one or more identified second routers are associated with the communication paths visible to the first router. The method further includes receiving at least one first response from at least one of the second routers, where the at least one first response identifies the communication paths visible to at least one of the second routers. In addition, the method includes broadcasting a second response at the first router, where the second response identifies the communication paths visible to at least one of the second routers and to the first router.

Abstract: An apparatus includes a plurality of resonators forming a filter. At least one of the resonators includes (i) a plurality of interdigital transducers positioned in a common acoustic track and (ii) a plurality of reflectors configured to reflect acoustic waves from the interdigital transducers back to the interdigital transducers. At least one reflector is positioned between adjacent interdigital transducers. The interdigital transducers in one of the resonators could be coupled in parallel or in series between an input and an output of that resonator.

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 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: A two port, single pole SAW resonator is employed for a local oscillator to eliminate the secondary frequency responses of the prior art without adding additional inductances and capacitances within an amplifier stage. The stray capacitance which is seen within the equivalent circuit of a single pole, two port SAW resonator at a port for the SAW resonator is tuned out by coupling an appropriately sized inductance in parallel with that stray capacitance. Access to the series resonator within the SAW resonator equivalent circuit is thus provided, permitting direct tuning of the resonant frequency for the SAW resonator. The high Q of the SAW resonator ensures low phase noise/edge jitter, while direct tuning of the series resonator enables a wide tune range. The tunable SAW resonator circuit is thus well-suited for use in a low phase noise tunable oscillator employed, for instance, in clock recovery within SONET applications.

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: 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 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: A vehicle includes a monitoring system capable of monitoring one or more measurable characteristics associated with the vehicle. The vehicle also includes a transceiver capable of broadcasting information associated with the one or more measurable characteristics for delivery to a controller. The transceiver is also capable of receiving information from at least one of the controller and another vehicle and broadcasting the received information for delivery to a destination other than the vehicle.

Abstract: A method includes receiving a first message at a router in a mesh network and synchronizing the router to a plurality of time slots using the first message. The method also includes repeatedly incrementing a network reference value at each time slot up to a maximum value and then decrementing the network reference value at each time slot down to a minimum value. In addition, the method includes broadcasting a second message at the router when the network reference value has a specific value that is associated with a unique identifier of the router.

Abstract: A method includes receiving a request to identify any communication paths visible to a first router in a mesh network and broadcasting the request. The method also includes identifying one or more second routers that broadcast information received by the first router, where the one or more identified second routers are associated with the communication paths visible to the first router. The method further includes receiving at least one first response from at least one of the second routers, where the at least one first response identifies the communication paths visible to at least one of the second routers. In addition, the method includes broadcasting a second response at the first router, where the second response identifies the communication paths visible to at least one of the second routers and to the first router.

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 two port, single pole SAW resonator is employed for a local oscillator to eliminate the secondary frequency responses of the prior art without adding additional inductances and capacitances within an amplifier stage. The stray capacitance which is seen within the equivalent circuit of a single pole, two port SAW resonator at a port for the SAW resonator is tuned out by coupling an appropriately sized inductance in parallel with that stray capacitance. Access to the series resonator within the SAW resonator equivalent circuit is thus provided, permitting direct tuning of the resonant frequency for the SAW resonator. The high Q of the SAW resonator ensures low phase noise/edge jitter, while direct tuning of the series resonator enables a wide tune range. The tunable SAW resonator circuit is thus well-suited for use in a low phase noise tunable oscillator employed, for instance, in clock recovery within SONET applications.

Abstract: To secure the benefits of a low phase noise, wide tune range SAW oscillator in noisy environments, the tunable two port SAW resonator circuit within the oscillator is employed in differential mode, connected to a differential amplifier circuit to create a differential oscillator. In the absence of any need for ground or power supply voltage level references, low phase noise/edge jitter is maintained even in hostile environments while providing sufficient tune range to track small frequency changes. The resulting differential mode SAW oscillator is thus well-suited for use, for instance, in clock recovery within SONET applications.

Abstract: A two port, single pole SAW resonator is employed for a local oscillator to eliminate the secondary frequency responses of the prior art without adding additional inductances and capacitances within an amplifier stage. The stray capacitance which is seen within the equivalent circuit of a single pole, two port SAW resonator at a port for the SAW resonator is tuned out by coupling an appropriately sized inductance in parallel with that stray capacitance. Access to the series resonator within the SAW resonator equivalent circuit is thus provided, permitting direct tuning of the resonant frequency for the SAW resonator. The high Q of the SAW resonator ensures low phase noise/edge jitter, while direct tuning of the series resonator enables a wide tune range. The tunable SAW resonator circuit is thus well-suited for use in a low phase noise tunable oscillator employed, for instance, in clock recovery within SONET applications.