Abstract: A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

Abstract: An antenna, system and method for transmitting and receiving RF signals over a first frequency band using a single antenna or two closely spaced antennas. In one embodiment, the antenna is configured to receive first signals in the first frequency band having a first rotational polarization and to transmit second signals in the first frequency band and having a second rotational polarization. The second signals may be transmitted in response to the first signals. The first signals may be preferentially routed to a receiver using signal conditioning circuitry that also routes the second signals from a transmitter to the antenna but not to the receiver.

Abstract: An amplifier powered by a selectively engageable voltage source and a method for operating the amplifier. The amplifier includes first and second electrodes for receiving an input signal to be amplified. The first and second electrodes are adapted to be respectively connected to coupling capacitors. The amplifier also includes a differential amplifier having inputs respectively connected to the first and second electrodes, and having an output. The amplifier additionally includes selectively engageable resistances coupled between the voltage source and respective inputs of the differential amplifier and defining, with the coupling capacitors, the high pass characteristics of the circuit. The amplifier further includes second selectively engageable resistances coupled between the voltage source and respective inputs of the differential amplifier.

Abstract: The present invention includes backscatter communication systems, interrogators, methods of communicating in a backscatter system, and backscatter communication methods. According to one aspect of the present invention, a backscatter communication system includes an interrogator including a transmitter configured to output a forward link communication and a receiver configured to receive a return link communication having a carrier signal, the receiver being configured to reduce the amplitude of the carrier signal of the return link communication; and a communication device configured to modulate the carrier signal to communicate the return link communication responsive to reception of the forward link communication.

Abstract: An interrogator for use in a backscatter system, the interrogator comprising an antenna configured to receive a backscatter signal; an IQ downconverter coupled to the antenna and configured to downconvert the backscatter signal to produce I and Q signals; a combiner coupled to the IQ downconverter and configured to combine the I and Q signals to produce a combined signal; and an analog to digital converter coupled to the combiner and configured to convert the combined signal to a digital signal. A method of communications in a backscatter system, the method comprising receiving a backscatter signal; downconverting the backscatter signal with an IQ downconverter to produce I and Q signals; combining the I and Q signals to produce a combined signal; and converting the combined signal to a digital signal.

Abstract: The present invention includes bit synchronizers and methods of synchronizing and calculating error. One method of synchronizing with a data signal in accordance with the present invention includes providing a data signal having a first portion and a second portion, generating a timing signal, first adjusting the timing signal during the first portion of the data signal, accumulating a history value during the first portion of the data signal, and second adjusting the timing signal during a second portion of the data signal using the history.

Abstract: A frequency doubler includes a first Gilbert cell, a second Gilbert cell coupled to the first Gilbert cell, a frequency generator configured to apply a first sinusoidal wave to the first Gilbert cell, and a phase shifter applying a sinusoidal wave shifted from the first sinusoidal wave to the second Gilbert cell. A method of doubling frequency without using a feedback loop includes providing a first Gilbert cell, providing a second Gilbert cell coupled to the first Gilbert cell, applying a first sinusoidal wave to the first Gilbert cell, and applying a sinusoidal wave shifted from the first sinusoidal wave to the second Gilbert cell.

Abstract: A stage for a ring oscillator, the stage including a first p-channel transistor having a gate defining a control node, having a source adapted to be coupled to a supply voltage, and having a drain; a second p-channel transistor having a gate coupled to the control node, having a source coupled to the supply voltage, and having a drain; a first n-channel transistor having a gate defining a first input, having a drain coupled to the drain of the first p-channel transistor and defining a first node, and having a source; a second n-channel transistor having a gate defining a second input, having a drain coupled to the drain of the second p-channel transistor and defining a second node, and having a source; a current source coupled to the sources of the first and second n-channel transistors directing current from the sources of the first and second n-channel transistors; a first resistor coupled between the supply voltage and the drain of the first n-type transistor; a second resistor coupled between the supply v

Abstract: The present invention includes backscatter communication systems, interrogators, methods of communicating in a backscatter system, and backscatter communication methods. According to one aspect of the present invention, a backscatter communication system includes an interrogator including a transmitter configured to output a forward link communication and a receiver configured to receive a return link communication having a carrier signal, the receiver being configured to reduce the amplitude of the carrier signal of the return link communication; and a communication device configured to modulate the carrier signal to communicate the return link communication responsive to reception of the forward link communication.

Abstract: An integrated circuit comprising a receiver, a transmitter, and a frequency lock loop configured to supply clock signals to the receiver and transmitter, the frequency lock loop including a current source having a thermal voltage generator, a current controlled oscillator having a plurality of selectively engageable current mirrors multiplying up the current of the current source, the frequency of the frequency lock loop varying in response to selection of the current mirrors, the current mirrors including transistors operating in a subthreshold mode.

Abstract: A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

Abstract: An interrogator for use in a backscatter system, the interrogator comprising an antenna configured to receive a backscatter signal; an IQ downconverter coupled to the antenna and configured to downconvert the backscatter signal to produce I and Q signals; a combiner coupled to the IQ downconverter and configured to combine the I and Q signals to produce a combined signal; and an analog to digital converter coupled to the combiner and configured to convert the combined signal to a digital signal. A method of communications in a backscatter system, the method comprising receiving a backscatter signal; downconverting the backscatter signal with an IQ downconverter to produce I and Q signals; combining the I and Q signals to produce a combined signal; and converting the combined signal to a digital signal.

Abstract: A bit synchronization device for an interrogator in a remote intelligent communication system wherein a programmable divider extracts a bit clock from the bits in a bitstream using a clock rate 64 times the data rate and wherein the divider is responsive to an early/late detector for adding or subtracting a count from the divider counter.

Abstract: A differentially phase shift keyed demodulator for use in an interrogator of a remote intelligent communication system. The demodulator includes a quadrature combiner delaying one of the quadrature signals and thereafter combining the delayed and undelayed signals along with a FIR matched filter, which filters the combiner output whereby the differentially phase shift keyed data on a sub-carrier can be demodulated using a simple delay and multiplying scheme in response to the filtered output.

Abstract: A remote intelligent communications device includes a primary RF communications port and an alternative modem communications port. The remote intelligent communications device receives configuration data for configuring the alternative modem communications port. The remote intelligent communications device obtains information data concerning a select attribute of an associated object. The information data is stored within internal memory of the remote intelligent communications device. Thereafter, the stored information data is retrieved, per one embodiment via the alternative modem port, from the remote intelligent communications device and analyzed for drawing conclusions regarding the select attribute of the associated object. Preferably, the remote intelligent communications device also includes a navigation (e.g. GPS) receiver that obtains navigation data, which navigation data is also stored within the internal memory of the remote intelligent communications device.