Abstract: A radio-frequency (RF) transmitter power amplifier circuit provides for practically linear performance by predistorting the amplifier input signals to compensate for amplifier distortion at high power levels, and provides a fine degree of control of amplifier power needed to handle complex modulation schemes with widely and rapidly varying power requirements. A predistortion database (20) contains gain and phase corrections for various transmission types and a separate automatic gain control database (38) contains fine amplifier gain corrections. A real-time processor (26) combines the two types of corrections and applies them to the amplifier input signals, and a background processor (16) continually updates both databases in accordance with a programmable priority scheme. Integration of predistortion and amplifier power control is achieved in a manner that minimizes adverse effects of one type of control on the other.

Abstract: An exemplary inertial measurement apparatus incorporates self-calibrating bias correction signals. First and second inertial instruments generate respective input signals representative of an inertial attribute to be measured. A bias estimator generates first and second bias correction signals. First and second summation nodes receive the respective input signals and the respective first and second bias correction signals. The first and second summation nodes provide respective summed signals to the first and second inertial instruments. The first and second inertial instruments generate respective output signals representative of a value of the inertial attribute based on the respective summed signals.

Abstract: One or more heating elements comprise a heating element. One or more elongated beams comprise an elongated beam. The heating element is coupled with the elongated beam and induces a time-varying thermal gradient in the elongated beam to cause one or more oscillations of one or more of the one or more elongated beams.

Abstract: A highly compact inductor formed on opposite faces of a dielectric substrate. Sets of parallel spaced conductive traces formed on the opposite faces of the substrate are interconnected by metallized vias through the substrate, in such a way as to form a continuous spiral conductive path. The inductor is preferably formed as two closely adjacent segments, each with conductive traces on each face of the substrate and each having metallized vias interconnecting the conductive traces. The segments are electrically connected in series and produce a magnetic field that extends through each segment in opposite directions and is closely coupled from one segment to the other. The inductor is, therefore, electromagnetically similar to a wire-wound toroidal inductor, providing high inductance and contourable Q values, but is highly compact, especially in the z-axis direction normal to the substrate.

Abstract: A fiber-optic gyroscope apparatus includes a light source, an optical coupler, a photodetector and an optical circuit device having at least one input, at least two outputs and a birefringent crystal substrate waveguide as a first segment of a Lyot type depolarizer between the input and the outputs. An input fiber of polarization maintaining fiber composition operating as a second segment of a Lyot type depolarizer is located between the optical coupler and the optical circuit device. A sensing coil is coupled to the outputs of the optical circuit device. The input fiber is fixed at approximately 45 degrees to the waveguide, with the input fiber and waveguide cooperating to form a Lyot type depolarizer. Other implementations of the fiber-optic gyroscope apparatus are also disclosed.

Abstract: A method (10) for etching a through via (116, 118) on a wafer (100) of semiconductor material (102), wherein the wafer (100) has a front side surface (110) and a backside surface (106), is described. A layer of photoresist material (104) is applied to the backside surface (106). The layer of photoresist (104) is then exposed to a light source through a mask having a pre-selected pattern, wherein the developed photoresist is removed to form at least one via (112, 114) in the remaining photoresist layer (104). The remaining photoresist layer (104?) is then baked in order to form a hardened, remaining photoresist layer (104?). The semiconductor material 102 adjacent to the at least one via (112, 114) is then gas plasma etched to form a through via (116, 118) between the backside surface (106) and the front side surface (110).

Abstract: A radiation pulse, such as from a solar simulator, is spectrally analyzed over a selected sampling pulse that is shorter in duration than the radiation pulse and is timed to begin after the start of the radiation pulse. A deformable membrane mirror is controlled to function as a high speed shutter in the path of the radiation pulse. When not deformed, the mirror reflects the radiation pulse into an optical instrument, such as a spectroradiometer. A sampling pulse is generated for a selected time after the start of the radiation pulse and is applied to the mirror to ensure total reflection of the radiation pulse only for the duration of the sampling pulse. Controls are provided to adjust the start time and duration of the sampling pulse, and to adjust the sensitivity of sensing the start of the radiation pulse.

Abstract: Monolithic microwave integrated circuit (MMIC) components and micro electromechanical systems (MEMS) components are integrated onto a single substrate at a wafer scale, by first performing MMIC and MEMS fabrication on a front face of a thick substrate wafer, bonding the substrate wafer to a cover wafer, thinning the back face of the substrate wafer and, finally, completing MMIC and MEMS fabrication on the back face of the thinned substrate wafer. The fabrication process is facilitated by use of a guard ring between the wafers to provide additional mechanical support to the substrate wafer and to protect the devices while the MMIC/MEMS fabrication is completed, and by a low temperature bonding process to join the substrate wafer and the cover wafer at multiple device cavity seal rings.

Abstract: A PIN electro-optical traveling wave modulator (10) including diffraction gratings (34, 36) positioned at opposing sides of an optical waveguide (20) that act to change the propagation pattern of the waveguide (20). The modulator (10) includes an N-type layer (14), a P-type layer (18) and an intrinsic layer (16) acting as the waveguide (20). A metal electrode (26) is in electrical contact with the N-type layer (14), and a metal electrode (30) is in electrical contact with the P-type layer (18). The electrodes (26, 30) define an RF transmission line. An optical wave (22) propagates along the waveguide (20) and interacts with the gratings (34, 36) which slow the optical wave (22) to match its speed to the speed of the RF wave in the transmission line. In one embodiment, the gratings (34, 36) are 2-D gratings formed by vertical holes (38) in the waveguide (20).

Abstract: A multi-carrier receiver system and method for receiving a transmission frequency multi-carrier signal include a feedforward cancellation loop. A frequency conversion circuit generates an intermediate frequency (IF) multi-carrier signal based on the transmission frequency multi-carrier signal. The feedforward cancellation loop generates an amplitude corrected multi-carrier signal based on the IF multi-carrier signal such that the amplitude corrected multi-carrier signal has a reduced dynamic range with respect to the IF multi-carrier signal. A primary A/D converter having a significantly lower dynamic range requirements can therefore generate a digital multi-carrier signal based on the amplitude corrected multi-carrier signal. The feedforward cancellation loop therefore enables the primary A/D converter to process multi-carrier signals without the need for large dynamic range requirements.

Abstract: A laser array architecture scalable to very high powers by fiber amplifiers, but in which the output wavelength is selectable, and not restricted by the wavelengths usually inherent in the choice of fiber materials. A pump beam at a first frequency is amplified in the fiber amplifier array and is mixed with a secondary beam at a second frequency to yield a frequency difference signal from each of an array of optical parametric amplifiers. A phase detection and correction system maintains the array of outputs from the amplifiers in phase coherency, resulting in a high power output at the desired wavelength. A degenerate form of the architecture is disclosed in an alternate embodiment, and a third embodiment employs dual wavelength fiber amplifiers to obtain an output at a desired difference frequency.

Abstract: An encoder circuit and a related method for its operation, in which digital encoding, such as differential phase-shift keyed (DPSK) encoding, is performed as a parallel operation on N bits at a time. Each encoded bit is both output in parallel with the others of the N bits and is coupled as an input to encode the immediately next bit in the input data stream. The Nth encoded bit is fed back to the first encoder stage for use in encoding the (N+1)th bit in the input stream. The encoder typically includes a serial-to-parallel converter at the encoder inputs, and a parallel-to-serial converter at the encoder outputs.

Abstract: An exemplary system that provides for navigation redundancy includes first and second navigation components adapted to determine first and second navigation parameters, respectively. A network component determines a relationship between the first and second navigation components, wherein the relationship describes a navigation solution for the second navigation component in terms of the first navigation component. A health monitor determines a health indicator for the second navigation component. The second navigation component determines a navigation solution for the second navigation parameters when the health indicator indicates a healthy condition. The network component determines a navigation solution for the second navigation parameters based on the relationship that describes behavior of the second navigation component in terms of the first navigation component when the health indicator indicates an unhealthy condition.

Abstract: A system and method to measure channel quality in terms of signal to interference plus noise ratio for the transmission of coded signals over fading channels in a communication system. A Viterbi decoder metric for the Maximum Likelihood path is used as a channel quality measure for coherent and non-coherent transmission schemes. This Euclidean distance metric is filtered in order to smooth out short term variations. The filtered or averaged metric is a reliable channel quality measure which remains consistent across different coded modulation schemes speeds. The filtered metric is mapped to the signal to interference plus noise ratio per symbol using a threshold based scheme. Use of this implicit signal to interference plus noise ratio estimate is used for the mobile assisted handoff in a cellular system, power control and data rate adaptation in the transmitter.

Abstract: A telephone with an automatic muting circuit that mutes the microphone in response to detection of speaking pauses of the local user to reduce noise due to acoustical feedback that are detected by comparing the waveforms from the microphone and the audio speaker after being amplified by amplifiers with automatic gain control circuits to the same level with speech subtractor. During pauses when the signals compared are substantially the same, then automatic muting circuit is activated by the speech subtractor to mute the microphone but when the local user speaks into the microphone the subtraction of the waveforms does not yield a null result and the microphone is unmuted.

Abstract: An automatic channel responsive television input source selection switch couples output signals from a selected one of a plurality of input television input source interface circuits to a television in accordance with a user channel selected with a user channel selector manually controlled through one of a remote control unit and interface and a manual interface. A look-up table memory stores each of the possible user channel numbers along with an associated input signal source channel and an indication of signal source identity, such as indication of a direct broadcast satellite television signal source, a public television broadcast source and a security camera source. The switch based on the associations stored in the look-up memory selects the associated video input signal source and provides an indication of the associated source channel number to a tuner included in the selected interface.

Abstract: An invalid mobile telephone call made within the service area of a vendor monitored by a vendor computer is detected by RF fingerprinting or the like results in transmission of a kill-call command over a TCP/IP network to a kill-call server that is interfaced with a mobile service center through a data link interface. The kill-call server determines whether the kill-call command is valid and, if so, then it transmits a message tear down request over the data link interface to an executive cellular processor which, if the kill-call capability is active, conveys a call termination message to the associated administrative call processing database node to effect the call termination.

Abstract: A longitudinal cancellation circuit for use in circuits providing a received differential signal containing a desired differential component and an undesired longitudinal component has a first multiplier for multiplying received differential signal with the longitudinal signal to produce a first signal having at least a DC component in addition to other frequency components. The first signal is received by a low-pass filter which produces a second signal containing only the DC component. A second multiplier multiplies the second signal with the undesired longitudinal signal to produce a third signal equal to the to the undesired longitudinal component. The third signal is subtracted from the received differential signal to produce the desired differential signal which is free of undesired longitudinal component.

Abstract: An improvement is disclosed for telecommunication PCM time division multiplex switching systems of the type having voice access ports, each with a voice path and a signalling path, and having PCM signalling and voice transmit buses to carry information to a switching network. From the network, PCM voice receive buses carry switched voice information to be demultiplexed, converted to analog form and connected to the voice port. A signalling bus carries information from the switching network to registers. The system is improved to enable it to switch data as well as voice information. A data port is provided to accompany each voice port, and the improved system includes means for multiplexing input data at the port and inserting it on the signalling transmit bus once the signalling portion of a call is completed. A receive data bus connects the signalling receive bus to means for demultiplexing data and presenting it to receive data ports.