Abstract:
A composite semiconductor (FIG. 43) (300) structure includes islands (302) of compound semiconductor materials formed on a noncompound substrate (303), and an optical testing structure. In one embodiment, a scan chain (301) runs through the noncompound substrate (303) (and possibly also through the islands (302)) and terminates in the islands at optical interface elements (304), one of which is an optical emitter and the other of which is an optical detector. A test device (FIG. 44) (400) inputs test signals to, and reads test signals from, the scan chain by interfacing (401) optically with the optical interface elements. In another embodiment (FIG. 46), an optical detector (604) is formed in the silicon substrate (52) and an optical emitter (605) is formed in the compound semiconductor material (66). A leaky waveguide (606) communicating with the emitter (605) overlies the detector (604), and detection by the detector of light (610) emitted by the emitter (605) is an indication of the absence of an intended circuit element between the detector (604) and the leaky side of the waveguide (606).
Abstract:
A fractional-N synthesizer (803) employing at least a second order sigma-delta modulator (900) is disclosed. The most significant bits from the output accumulator (1011) of the sigma-delta modulator are used as the carry out control for the variable divisor of the loop divider (103). Modulation to the synthesizer is introduced as part of the digital number input to sigma-delta modulator and spurious signal output is reduced by selection of a large number as the denominator of the fractional portion of the loop divider divisor.
Abstract:
Un synthétiseur fractionnaire de type N (803) utilisant au moins un modulateur (900) sigma-delta de deuxième ordre est décrit. Les binaires les plus significatifs de l'accumulateur de sortie (1011) du modulateur sigma-delta sont utilisés comme commande d'exécution pour le diviseur variable du démultiplicateur à boucle (103). Le signal de modulation envoyé au synthétiseur fait partie de l'entrée numérique d'un chiffre dans le modulateur sigma-delta et la production de signaux parasites est réduite au moyen de la sélection d'un chiffre élevé comme dénominateur de la partie fractionnaire du diviseur du démultiplicateur à boucle.
Abstract:
High quality epitaxial layers of monocrystalline materials can be grown overlying monocrystalline substrates such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. The compliant substrate includes an accommodating buffer layer on at least a portion of a silicon wafer (52). The accommodating buffer layer (60) is a layer of monocrystalline oxide spaced apart from the portion of the silicon wafer (52) by an amorphous interface layer (62) of silicon oxide. The amorphous interface layer (62) dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer (60). A device structure (51) for interacting with magnetic storage media (110) is formed overlying the monocrystalline substrate (52). Portions or an entirety of the device structure (51) can also overly the accommodating buffer layer (60), or the monocrystalline material layer (52).
Abstract:
A radio receiver having at least two operational states and including a variable gain amplifier and at least two adaptive DC offset compensators (421, 427) to suppress undesired DC offset. The first operational state of the radio receiver (121) adjusts the adaptive DC offset compensator circuits (421, 427) to appropriate output levels in absence of an input signal to the radio receiver (121). The second operational state receives the input signal through the radio receiver (121) and eliminates the undesired DC offset (309) from the received input signal with the adaptive DC offset compensator circuits (421, 427) and allows the received input signals to be processed.
Abstract:
High quality epitaxial layers of monocrystalline materials (132, 166, 170) can be grown overlying monocrystalline substrates (110, 161, 3811) by forming a compliant substrate for growing the monocrystalline layers. One way to achieve compliancy includes first growing on a silicon wafer an accommodating buffer layer (124, 164) that is a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer (122, 162) of silicon oxide. The amorphous interface layer (122, 162) dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer (124, 164. In this way, an integrated circuit (3810, 160, 4200) that distributes its clock signals optically is provided. The integrated circuit (3810, 160, 4200) preferably includes a plurality of digital CMOS circuits (181, 3813) that communicate optically. The optical devices (180, 3814, 3815) are preferably formed from compound semiconductor structures (3812).
Abstract:
High quality epitaxial layers of monocrystalline materials (132, 166, 170) can be grown overlying monocrystalline substrates (110, 161, 3811) by forming a compliant substrate for growing the monocrystalline layers. One way to achieve compliancy includes first growing on a silicon wafer an accommodating buffer layer (124, 164) that is a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer (122, 162) of silicon oxide. The amorphous interface layer (122, 162) dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer (124, 164. In this way, an integrated circuit (3810, 160, 4200) that distributes its clock signals optically is provided. The integrated circuit (3810, 160, 4200) preferably includes a plurality of digital CMOS circuits (181, 3813) that communicate optically. The optical devices (180, 3814, 3815) are preferably formed from compound semiconductor structures (3812).
Abstract:
High quality epitaxial layers of monocrystalline materials can be grown overlying monocrystalline substrates such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. The compliant substrate includes an accommodating buffer layer over a portion of a silicon wafer (254). The accommodating buffer layer (260) is a layer of monocrystalline oxide spaced apart from the portion of silicon wafer by an amorphous interface layer (262) of silicon oxide. The amorphous interface layer (262) dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer (260). A device structure (250) for interacting with optical storage media (300) is formed overlying the portion of silicon wafer (254). Portions or an entirety of the device structure (250) can also overly the accommodating buffer layer (260) , or the portion of the silicon wafer (254).
Abstract:
A multiple latched accumulator fractional-N synthesizer for use in digital radio transceivers is disclosed. The divisor of the frequency divider (103) of the synthesizer is varied with time by the summation of accumulator carry output digital sequences which result in frequency increments equal to a fraction of the reference frequency. The accumulators (615, 617) are latched such that upon the occurrence of a clock pulse, data is transferred through each accumulator one clock pulse step at a time, such that the delay through the system is equal to that of only one accumulator. The carry outputs of the accumulators (615, 617) are coupled through delays (645, 647, 649, 631, 633) equal to one less delay than the number of accumulators and added (635) such that all higher order accumulator carry outputs add to a net summation of zero so as to not upset the desired fractional setting of the first accumulator.
Abstract:
A method and apparatus for diversity reception in a communication system is provided. A dual branch receiver (102, 103) is provided with a stored replica of expected reference information so that correlation with received time-dispersed signals (100, 101) produces an estimate of the transmission channel's impulse response as seen by each branch, and determines, among other things, phase error between the branch local oscillators and the time-dispersed signals. Matched filters (214, 215) are constructed which then coherently align the time-dispersed signals from each branch with that branch's local oscillator (208, 209) which constitutes a part of the signal equalization. A diversity processor (105) performs bit by bit selection on the re-aligned signals, maximal ratio combining of the re-aligned signals, or equal gain combining of the re-aligned signals, followed by a sequence estimation which uses similarly selected or combined channel distortion compensation parameters to complete the equalization process on the new signal.