Abstract: A transmission line balun eliminates unwanted reflection of signal energy coupling to a ground plane. A junction of the conductive segments connected to the unbalanced port on the balun is connected to the ground plane with a resistor. The selected junction is a virtual ground of the balun, so the presence of the resistor does not degrade the balun performance. The resistor dissipates the energy from the parasitic mode propagating with the ground plane so that no signal is reflected back to short out the signal source. The value of the resistor is selected to facilitate maximum termination of the parasitic mode propagation.

Abstract: Tracking error in phase locked loop (PLL) devices is addressed utilizing feed-forward phase modulation. Specifically, the phase difference of the reference signal and said oscillator signal of a PLL may be determined utilizing a phase detector. The output of the phase detector may be provided to a loop filter to provide feedback to the VCO of the PLL. Additionally, the filtered phase difference may be provided to a suitably calibrated phase modulator to add an amount of phase modulation to the oscillator signal that is approximately equal and opposite to said phase difference to generate a corrected phase output signal.

Abstract: An amplifier circuit apparatus for driving a laser device, the apparatus comprising a multistage amplifier including an output stage, wherein at least one device for band limiting a signal is coupled to the multistage amplifier prior to the output stage.

Abstract: A unipolar photodiode and methods of making and using employ a Schottky contact as a cathode contact. The Schottky cathode contact is created directly on a carrier traveling or collector layer of the unipolar photodiode resulting in a simpler overall structure to use and make. The unipolar photodiode comprises a light absorption layer, the collector layer adjacent to the light absorption layer, the Schottky cathode contact in direct contact with the collector layer, and an anode contact either directly or indirectly interfaced to the light absorption layer. The light absorption layer has a doping concentration that is greater than a doping concentration of the collector layer. The light absorption layer has a band gap energy that is less than that of the collector layer. The light absorption layer and the collector layer may be of the same or opposite conduction type.

Abstract: The magnitude of a pulse in a signal having both positive and negative polarity pulses (for example, a ternary PDH signal) is determined by measuring the magnitude of multiple samples of the signal. A reference level for the signal is determined from a plurality of these sample magnitudes, and the magnitude of a pulse in the signal is determined from the sample magnitudes and the reference level.

Abstract: A method of generating an IC design comprises the steps of generating an intermediate routing result to define interconnects between functional blocks on an IC. The next step is defining one or more repeater ranches in an interstice of the IC and generating a repeater placement plan for placement of repeater elements according to the repeater ranch boundary constraints. The process continues with the step of generating a final routing result to define interconnects between functional blocks that interconnect the repeater elements according to the repeater placement plan.

Abstract: Systems and methods for wideband single-end probing of variably spaced probe points are provided. One such embodiment includes a probe housing. The probe housing at least partially surrounds a probe barrel. A probe barrel end cap extends from the probe barrel and at least partially surrounds a probe tip. The longitudinal axis of the probe tip is offset from the longitudinal axis of the probe barrel. A ground tip is adjacent to the probe tip and electrically connected to the probe barrel. Methods are also provided.

Abstract: An electrical relay that uses a conducting liquid in the switching mechanism. In the relay, a pair of fixed electrical contacts is held a small distance from a pair of moveable electrical contacts. The facing surfaces of the contacts each support a droplet of a conducting liquid, such as a liquid metal. A piezoelectric or magnetorestrictive actuator is energized to move the pair of moveable contacts, closing the gap between one of the fixed contacts and one of the moveable contacts, thereby causing conducting liquid droplets to coalesce and form an electrical circuit. At the same time, the gap between the other fixed contact and the other moveable contact is increased, thereby causing conducting liquid droplets to separate and break an electrical circuit. The actuator is then de-energized and the moveable electrical contacts return to their starting positions. The volume of liquid metal is chosen so that liquid metal droplets remain coalesced or separated because of surface tension in the liquid.

Abstract: Data cells traversing an Asynchronous Transfer Mode (ATM) network (10) are passively monitored by probes at two spaced points (12,14). A filtering characteristic is applied to select cells comparatively infrequently, and timestamps or sequence numbers (or both) for the cells selected at each point are forwarded to a correlator (28). The correlator identifies similarities in the temporal patterns of intervals between timestamps received from each probe, and uses these similarities to identify and correlate timestamps relating to occurrence of the same cell at the two monitored points. The correlated timestamps are used to determine parameters indicative of the performance of the network, such as one-way delay, variation in that delay, and rate of cell loss.

Abstract: Methods are provided for identifying heterogeneous features, including heterogeneous background regions, in an image of an array, e.g., in an image of a biopolymeric array, such as a nucleic acid array. The subject methods employ an algorithm that employs a different dispersity measure depending on whether the signal features are weaker or stronger. Also provided are computer readable storage media that include an algorithm capable of performing the steps of the subject methods. The subject methods find use in the processing of images obtained from a variety of different types of arrays, including nucleic acid arrays.

Abstract: A network analyzing apparatus that analyzes the network properties of a device under test by applying reference signals to a device under test by frequency sweeping or power sweeping comprises input device for inputting the sweep range and sweep interval of these reference signals as well as the center coordinates and radius of a test circle for testing this device under test; a measurement apparatus for measuring the network properties of this device under test and obtaining measurements for n number of measurement points determined from this sweep range and sweep interval; and a testing apparatus, with this testing apparatus finding the difference between this measurement and center coordinates and, referring to this difference and this radius, determining that this measurement that has been read passes the test if the magnitude of this referred difference is no greater than this referred radius, or is less than this referred radius.

Abstract: In an optical communications system, it is necessary to control the extinction ratio of a laser device (192) of an optical transmission unit. The laser device (192) is typically used to transmit a signal that can be approximated by a pseudo-random bit stream. The bit stream is monitored by collecting light from a back facet of the laser device (192) using a photodiode (194) in a control loop. Due to band limiting effects of the photodiode (194) and parasitic circuit track capacitances, a feedback signal generated by the photodiode (194) becomes distorted, leading to difficulties in controlling the extinction ratio. The present invention therefore provides an apparatus that simulates a signal generated by the photodiode (194) and subsequent processing of the photodiode signal. The simulated signal and the processed photodiode signal are compared so as to generate a control signal for controlling modulation amplitude of the laser device (192) and hence the extinction ratio.

Abstract: A fixture assembly is presented. The fixture assembly includes a device assembly for mating with a device under test and a tester interface assembly for mating with the device assembly on one side and a tester on a second side. In the method and apparatus of the present invention, the device assembly includes a probe field specific to a device under test and may be changed to accommodate a different device, without changing the tester interface assembly. The tester interface assembly includes a frame used for alignment and structural support. The frame interfaces with a probe plate on one side and a load plate on the other side. The probe plate holds a plurality of probes in place while the load plate provides a plurality of holes for the probes to extend downward through the load plate. A printed circuit board (PCB) is positioned below the load plate and makes contact with the ends of the probes.

Abstract: Systems and methods for wideband differential probing of variably spaced probe points are provided. One such embodiment includes a probe housing at least partially surrounding a first probe barrel and a second probe barrel. A first probe barrel end cap and a second probe barrel end cap extend respectively from the first and second probe barrels and also at least partially surround respectively a first probe tip and a second probe tip. The longitudinal axes of the first and second probe tips are offset respectively from the longitudinal axes of the first and second probe barrels. Methods are also provided.

Abstract: A circuit board coupon testing method and apparatus. A coupon tester uses a linear actuator to carry a test head and probe(s) for an LCR meter. The linear actuator accurately steps the probe(s) over a coupon of components arranged linearly adjacent an edge of the circuit board to measure the parameters of the component. The coupon tester can be integrated with an in-circuit tester to provide further functionality, with the coupon test being carried out simultaneously with a portion of the in-circuit test such as an unpowered portion of the in-circuit test.

Abstract: A method and system for producing a compact uniform illumination beam that does not have a positional blind spot. First, non-collimated light beams that have a positional blind spot are received from a light source. Next, the non-collimated light beams are converted into approximately collimated light beams without the positional blind spot. Then, the collimated light beams are split into a plurality of split beams. These split beams are then overlapped to form a compact and uniform illumination beam.

Abstract: A thin-film resonator having a seed layer and a method of making the same are disclosed. The resonator is fabricated having a seed layer to assist in the fabrication of high quality piezoelectric layer for the resoantor. The resonator has the seed layer, a bottom electrode, piezoelectric layer, and a top electrode. The seed layer is often the same material as the piezoelectric layer such as Aluminum Nitride (AlN).

Abstract: The nitride semiconductor layer structure comprises a buffer layer and a composite layer on the buffer layer. The buffer layer is a layer of a low-temperature-deposited nitride semiconductor material that includes AlN. The composite layer is a layer of a single-crystal nitride semiconductor material that includes AlN. The composite layer includes a first sub-layer adjacent the buffer layer and a second sub-layer over the first sub-layer. The single-crystal nitride semiconductor material of the composite layer has a first AlN molar fraction in the first sub-layer and has a second AlN molar fraction in the second sub-layer. The second AlN molar fraction is greater than the first AlN molar fraction. The nitride semiconductor laser comprises a portion of the above-described nitride semiconductor layer structure, and additionally comprises an optical waveguide layer over the composite layer and an active layer over the optical waveguide layer.

Abstract: An apparatus includes a mixer, a combiner and first and second reflectors. The mixer has first and second inputs and has first and second outputs. The combiner includes first and second parts where the first output provides a mixed signal to the first part and the second part provides a combined signal to the second input. The first reflector receives a remaining signal from the first part and provides a reflected composite signal to the second part. The second reflector receives a split off pump signal from the first part and provides a reflected pump signal to the second part.

Abstract: The invention provides an arbitration unit adapted for controlling accesses to a shared storage. The arbitration unit comprises a set of interfaces adapted for connecting a plurality of units with said arbitration unit, wherein outgoing data streams are transmitted from the arbitration unit via respective ones of said interfaces to at least one of said units, and wherein incoming data streams are transmitted from at least one of said units via respective ones of said interfaces to the arbitration unit. A control logic is connected to each of said interfaces, said control logic being adapted for segmenting write data of incoming data streams in order to set up write accesses to said shared storage, for scheduling a sequence of at least one of write and read accesses to said shared storage, and for distributing read data obtained during said read accesses to outgoing data streams.