Abstract: According to one embodiment of the invention, a digital to analog converter for converting a digital signal to an analog optical signal includes a light source and a plurality optical switches. Each optical switch is responsive to a respective one of a plurality of bits of a digital signal to selectively allow transmission of light from the light source through the switch. The digital to analog converter also includes a light combination system operable to combine the light passed through each of the switches and produce an analog optical signal indicative of the digital signal.

Abstract: An apparatus includes a distributed resonant tunneling section with a plurality of inductive portions that are coupled in series with each other between first and second nodes, such that a respective further node is present between each adjacent pair of the inductive portions. The distributed resonant tunneling section also has a plurality of resonant tunneling device portions which are each coupled between a third node and a respective one of the further nodes.

Abstract: A latch circuit includes first and second resonant tunneling diodes coupled in series, and a reset portion having a photodiode portion responsive to varying photonic energy for switching between first and second states which are different. When the photodiode portion is in its first state, the reset portion normalizes a voltage across each of the resonant tunneling diodes.

Abstract: According to one embodiment of the invention, a digital to analog converter for converting a digital signal to an analog optical signal includes a light source and a plurality optical switches. Each optical switch is responsive to a respective one of a plurality of bits of a digital signal to selectively allow transmission of light from the light source through the switch. The digital to analog converter also includes a light combination system operable to combine the light passed through each of the switches and produce an analog optical signal indicative of the digital signal.

Abstract: A film stack and a method for fabricating the same. In one embodiment, a film stack comprises a semiconductor substrate with the following layers: a first layer of oxide over the substrate; a first layer of polycrystalline silicon over the first layer of oxide; a second layer of oxide over the first layer of polycrystalline silicon; a second layer of polycrystalline silicon over the second layer of oxide; a third layer of oxide over the second layer of polycrystalline silicon; and a layer of nitride over the third layer of oxide. The second layer of polycrystalline silicon and the third layer of oxide reduce the formation of bird's beaks after liner oxidation of a trench formed in the film stack. The reduced bird's beaks prevent unwanted residual strings of the first layer of polycrystalline silicon remaining after subsequent processing of the film stack.

Abstract: An apparatus includes a distributed resonant tunneling section with a plurality of inductive portions that are coupled in series with each other between first and second nodes, such that a respective further node is present between each adjacent pair of the inductive portions. The distributed resonant tunneling section also has a plurality of resonant tunneling device portions which are each coupled between a third node and a respective one of the further nodes.

Abstract: Digital phased array architecture and associated method are disclosed that eliminate the necessity of utilizing analog phase shifters in the receive and transmit signal paths. Desired delays are instead generated by adjusting the timing of sampling signals sent to analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) in the receive and transmit signal paths.

Abstract: A latch circuit includes first and second resonant tunneling diodes coupled in series, and a reset portion having a photodiode portion responsive to varying photonic energy for switching between first and second states which are different. When the photodiode portion is in its first state, the reset portion normalizes a voltage across each of the resonant tunneling diodes.

Abstract: An apparatus includes a resonator portion responsive to electromagnetic radiation within a frequency range, a converter portion responsive to radiation received by the resonator portion for emitting electromagnetic radiation within a different frequency range, and a detector portion which detects the radiation emitted by the converter portion. According to one feature, the resonator portion, the converter portion and the detector portion are respective parts of an integrated circuit. According to a different feature, the radiation emitted by the converter portion is infrared energy.

Abstract: An apparatus includes a circuit having first and second portions which are each coupled between first and second nodes. The first portion includes a resonant tunneling device, and the second portion has a reactance that includes, at a selected frequency, a complex conjugate reactance of a reactance of the resonant tunneling device. The complex conjugate reactance substantially cancels the reactance of the resonant tunneling device at the selected frequency.

Abstract: An apparatus includes a distributed resonant tunneling section with a plurality of inductive portions that are coupled in series with each other between first and second nodes, such that a respective further node is present between each adjacent pair of the inductive portions. The distributed resonant tunneling section also has a plurality of resonant tunneling device portions which are each coupled between a third node and a respective one of the further nodes.

Abstract: A resonant tunneling diode or diode array oscillator (10) including a resonant diode (11) is coupled to a millimeter-wave source (14) and a quench generator (16) for periodically quenching the oscillations so that the average oscillation time of the oscillator is proportional to signal strength of the source (14). The signal source can be from an antenna such as a dipole or tapered slot line antenna.

Abstract: An apparatus includes a distributed resonant tunneling section with a plurality of inductive portions that are coupled in series with each other between first and second nodes, such that a respective further node is present between each adjacent pair of the inductive portions. The distributed resonant tunneling section also has a plurality of resonant tunneling device portions which are each coupled between a third node and a respective one of the further nodes.

Abstract: A circuit includes a resonant tunneling device which is responsive to an input signal for causing an electrical signal characteristic to undergo a quantum jump in magnitude that takes an interval of time. According to one feature, a differentiator responds to the quantum jump in magnitude by producing a narrow pulse with a duration which is approximately the interval of time. According to a different feature, a sampling portion responds to the quantum jump in magnitude by sampling a signal during a time period having a duration which is approximately the interval of time.

Abstract: An apparatus includes a resonator portion responsive to electromagnetic radiation within a frequency range, a converter portion responsive to radiation received by the resonator portion for emitting electromagnetic radiation within a different frequency range, and a detector portion which detects the radiation emitted by the converter portion. According to one feature, the resonator portion, the converter portion and the detector portion are respective parts of an integrated circuit. According to a different feature, the radiation emitted by the converter portion is infrared energy.

Abstract: A circuit includes a resonant tunneling device which is responsive to an input signal for causing an electrical signal characteristic to undergo a quantum jump in magnitude that takes an interval of time. According to one feature, a differentiator responds to the quantum jump in magnitude by producing a narrow pulse with a duration which is approximately the interval of time. According to a different feature, a sampling portion responds to the quantum jump in magnitude by sampling a signal during a time period having a duration which is approximately the interval of time.

Abstract: An apparatus includes a quantizer circuit having a resonant tunneling device with an operational characteristic that includes a first region of unstable operation, and second and third regions of stable operation. An input terminal and an output terminal are each coupled to one end of the resonant tunneling device. A bias section is coupled to the resonant tunneling device, and responds to a clock signal by alternately operating in a first mode where the resonant tunneling device is forced to operate within the first region, and a second mode where the resonant tunneling device is permitted to operate in either of the second and third regions.

Abstract: A digital phased array antenna comprises a plurality of antenna elements, each element receiving an incoming signal. An analog-to-digital converter is coupled to at least one of the antenna elements to convert the incoming signal to a multi-bit digital signal. A demodulator or de-ramp circuit is coupled to the analog-to-digital converter to reduce the bandwidth of the multi-bit signal.

Abstract: A system for sampling an input signal includes a plurality of analog-to-digital converters operable to convert the input signal into digital output signals. At least one of the analog-to-digital converters is also operable to receive a bias voltage different than a bias voltage received by at least one other analog-to-digital converter and to convert the input signal into the digital output signal using the bias voltage. The system also includes a digital accumulator coupled to the analog-to-digital converters. The digital accumulator is operable to receive the digital output signals from the analog-to-digital converters and to generate a net digital output signal comprising a sum of the digital output signals.

Abstract: A highly miniaturized nanomechanical transistor switch is fabricated using a mechanical cantilever which creates a conductive path between two electrodes in its deflected state. In one embodiment, the cantilever is deflected by an electrostatic attraction arising from a voltage potential between the cantilever and a control electrode. In another embodiment, the cantilever is formed of a material with high magnetic permeability, and is deflected in response to complementary magnetic fields induced in the cantilever and in an adjacent electrode. The nanomechanical switch can be fabricated using well known semiconductor fabrication techniques, although semiconductor materials are not necessary for fabrication. The switch can rely upon physical contact between the cantilever and the adjacent electrode for current flow, or can rely upon sufficient proximity between the cantilever and the adjacent electrode to allow for tunneling current flow.