Abstract: A method and system of applying modulated carrier signals to tree networks and processing signals tapped from the tree networks to generate output signals with phase-synchronized carriers are disclosed.

Abstract: A method and system of applying modulated carrier signals to tree networks and processing signals tapped from the tree networks to generate output signals with phase-synchronized carriers are disclosed.

Abstract: Frequency dependent I/Q imbalance in real I/Q filter pairs compensation may be performed using a simple compensation module, placed in the receiver/transmitter chain, with a gain adjustment coefficient and a delay adjustment coefficient. The gain adjustment coefficient may be determined by amplitude measurements conducted at a selected frequency near the center of the band-pass region of the filters. The delay adjustment coefficient may be determined by phase measurements conducted at a selected frequency near the edge of the band-pass region of the filters. Statistical analysis may be used to determine types of real filters that are better suited for the compensation method and to select the test frequencies that should be used.

Abstract: A method and system of applying modulated carrier signals to tree networks and processing signals tapped from the tree networks to generate output signals with phase-synchronized carriers are disclosed.

Abstract: A method involving: distributing two clock signals over a clock signal distribution system; in each of a plurality local clocking regions located along the signal distribution system, detecting the two clock signals and generating therefrom a local clock signal for that local clocking region, wherein the generated local clock signals for at least some of the plurality of local clocking regions are in a first group all of which are aligned in phase with each other and the generated local clock signals for the remainder of the plurality of local clocking regions are in a second group all of which are aligned in phase with each other, and wherein the phase of the first group is out of phase with the phase of the second group by a predetermined amount; and bringing all of the clock signals for the plurality of local clocking regions into phase alignment so that the phase of the first group is in phase with the phase of the second group.

Abstract: The method involves detecting a first signal characterized by a periodically occurring first event, detecting a second signal characterized by a periodically occurring second event, and based on both the detected first and second signals, generating a third signal characterized by a periodically occurring third event. The method also involves automatically adjusting the phase of the third signal so that the periodically occurring third event occurs at a predetermined location between the first and second events of the first and second signals.

Abstract: Methods and apparatus are provided for preventing a third party from listening to a conversation between at least two participants on a telephone. The telephone generates an audio stimulus signal that is presented through a secondary speaker. The audio stimulus signal may be, for example, pseudorandom noise or a cancellation signal. According to one aspect of the invention, the telephone ensures that the audio stimulus signal does not significantly impair the conversation for the at least two participants. To prevent the third party from listening to the local portion of the conversation, the audio stimulus signal is subtracted from the received signal prior to presenting the received signal to the user. To prevent the third party from listening to the remote portion of the conversation, the audio stimulus signal is subtracted from the received signal.

Abstract: Methods and apparatus are disclosed for adjusting the frequency tuning range of an oscillator circuit. The oscillator circuit is comprised of at least two MOS devices; a first reactance connecting a drain electrode of a first MOS device to a gate electrode of a second MOS device and a second reactance connecting a drain electrode of the second MOS device to a gate electrode of the first MOS device; and a tank circuit connected to the source and drain electrodes. The first and second reactance may comprises a capacitor or a diode or a combination thereof. In addition, one or more resistors may optionally be connected between a gate electrode of at least one of the MOS device and a power source.

Abstract: A clock signal distribution circuit including: a signal transmission system having first and second signal transmission lines, each extending from the first end to the second end of the signal transmission system, the first signal transmission line for carrying a first periodic signal from the first end to the second end of the signal transmission system, the second signal transmission line for carrying a second periodic signal from the second end to the first end of the signal transmission system transmission; and a local clock signal generator circuit including a detector system for detecting at a preselected location along the signal transmission system the first and second periodic signals, wherein the generator circuit generates from both the detected first and second periodic signals a local clock signal that has a predetermined skew that is between to the skews of the detected first and second periodic signals.

Abstract: A system for generating a local clock signal, the system including: a skew correction circuit for receiving first and second periodic signals that have associated skews, wherein the skew correction circuit is configured to use the received first and second periodic signals to generate a third periodic signal that has a fixed skew between the skews of the first and second periodic signals; a phase detector with a first input that receives the third periodic signal from the skew correction circuit and a second input; a variable oscillator for generating an output signal having a frequency that is controlled by the phase detector; and a frequency divider for dividing the frequency of the oscillator's output signal, wherein the frequency-divided output signal is fed back to the second input of the phase detector, and wherein the local clock signal is derived from the oscillator's output signal.

Abstract: An integrated circuit including: a clock signal distribution network for carrying two global clock signals traveling in opposite directions; a plurality of local clocking regions arranged along the network, each of which includes a local clock signal generation circuit that generates a local clock signal based upon the two global clock signals; and a plurality of phase detectors each of which is associated with a different one of the local clocking regions and is configured to compare the local clock signal for that local clocking region with the local clock signal for a neighboring local clocking region, wherein in each of at least some of the local clocking regions the local clock signal generation circuit is configured to align the local clock signal for that region with the local clock signal of the neighboring region when the phase detector for that local clocking region indicates a nonalignment condition exists.

Abstract: A method involving: distributing two clock signals over a clock signal distribution system; in each of a plurality local clocking regions located along the signal distribution system, detecting the two clock signals and generating therefrom a local clock signal for that local clocking region, wherein the generated local clock signals for at least some of the plurality of local clocking regions are in a first group all of which are aligned in phase with each other and the generated local clock signals for the remainder of the plurality of local clocking regions are in a second group all of which are aligned in phase with each other, and wherein the phase of the first group is out of phase with the phase of the second group by a predetermined amount; and bringing all of the clock signals for the plurality of local clocking regions into phase alignment so that the phase of the first group is in phase with the phase of the second group.

Abstract: A method involving: in a signal distribution system including a first line and a second line both of which extend from the first end to the second end of the signal distribution system, introducing a first global clock signal into the first line so that the first global clock signal propagates from the first end to the second end of the line; introducing a second sinusoidal global clock signal into the second line so that the second global clock signal propagates from the second end to the first end of the line; and in each of a plurality of local clocking regions located along the signal distribution system, detecting the first and second global clock signals; multiplying the detected first and second clock signal for that local clocking region together to generate a combined signal, and deriving a local clock signal for that local clocking region from the combined signal.

Abstract: A method involving: detecting a first signal characterized by a periodically occurring first event; detecting a second signal characterized by a periodically occurring second event; and based on both the detected first and second signals, generating a third signal characterized by a periodically occurring third event, wherein generating the third signal involves automatically adjusting the phase of the third signal so that the periodically occurring third event occurs at a predetermined location between the first and second events of the first and second signals.

Abstract: A method and apparatus for receiving a first signal characterized by a periodically occurring first event; receiving a second signal characterized by a periodically occurring second event; delaying the first signal by a controllable amount of delay to generate a third signal characterized by a periodically occurring third event; and based on relative timing of the first and second signals, controlling the amount of delay so that the periodically occurring third event occurs at a predetermined location between the first and second events of the first and second signals.

Abstract: Power amplifiers are disclosed that demonstrate improved linearity and efficiency in applications requiring significant peak-to-average ratios (PAR). A power amplifier in accordance with the present invention comprises a first transistor in an input stage that converts DC power into AC power; and a second transistor in a negative conductance stage that has a current-voltage characteristic with at least two slopes. The at least two slopes of the current-voltage characteristic are separated by a break point that may be controlled. The power amplifier may also include a non-dissipative two-port device that has two AC ports. The non-dissipative two-port device has a Z matrix with two zero-valued diagonal elements and two complex valued off-diagonal elements having a same sign and only imaginary parts for an operating frequency. In one implementation, the diagonal entries of the Z matrix are small at twice the operating frequency.

Abstract: A power device(s) is biased and operates in Class-AB. Crossover distortion is minimized over a broad range of operating conditions, not only for a nominal case. The bias current of a power transistor is automatically adjusted in response to process and temperature variations. Preferably, the adjustment is performed using an error-feedback arrangement. An exemplary ‘rule’ for bias adjustment involves satisfying a proportionality relationship between the small-signal device transconductance at the operating point, and a maximum device transconductance. A dual replica master-slave control architecture is utilized. A self-adapting circuit is provided to change the bias current (or voltage) so that the value is always the optimum value, irrespective of operating temperature and/or process variations. Self-biasing is introduced wherein no manual adjustment is necessary. A stable amplifier is formed having great robustness to process and temperature variations.

Abstract: Methods and apparatus are disclosed for adjusting the frequency tuning range of an oscillator circuit. The oscillator circuit is comprised of at least two MOS devices; a first reactance connecting a drain electrode of a first MOS device to a gate electrode of a second MOS device and a second reactance connecting a drain electrode of the second MOS device to a gate electrode of the first MOS device; and a tank circuit connected to the source and drain electrodes. The first and second reactance may comprises a capacitor or a diode or a combination thereof. In addition, one or more resistors may optionally be connected between a gate electrode of at least one of the MOS device and a power source.

Abstract: Electronic modules are interconnected with one another by means of communication (e.g., ultrasonic) links, In one embodiment, in a local conference call environment, only one wireless RF link is necessary—between a master cell phone and a base station, whereas all other voice modules are interconnected with one another and with the master via ultrasonic links. In another embodiment, a master voice module (with or without an RF link to a base station) includes at least one detachable module (e.g., an earpiece and/or mouthpiece) that is interconnected with the master via an ultrasonic link. In yet another embodiment, a detachable module includes a capacitor, which serves as its power supply and which is recharged when it is attached a master module (e.g., by a battery in the master module).

Abstract: Methods and apparatus are provided for preventing a third party from listening to a conversation between at least two participants on a telephone. The telephone generates an audio stimulus signal that is presented through a secondary speaker. The audio stimulus signal may be, for example, pseudorandom noise or a cancellation signal. According to one aspect of the invention, the telephone ensures that the audio stimulus signal does not significantly impair the conversation for the at least two participants. To prevent the third party from listening to the local portion of the conversation, the audio stimulus signal is subtracted from the received signal prior to presenting the received signal to the user. To prevent the third party from listening to the remote portion of the conversation, the audio stimulus signal is subtracted from the received signal.