Abstract: A wind turbine blade is configured such that the lift force from the blade airfoil is always normal, or nearly normal, to the shaft torque. This condition maximizes energy conversion. This objective may be achieved by a) having the airfoil chord always aligned to the actual wind direction (subject only to small angle of attack variations), and b) slowing the turbine rotation rate so that no blade twist is needed. As a result, blade tip speed due to shaft rotation is less than the wind speed, and preferably much less. This low tip speed eliminates any hazard to birds. The lift force from the blade airfoil directly drives the torque on the shaft, so the control problem simplifies to adjusting the blade angle of attack to keep the lift constant across varying wind speeds. For most airfoils, a slightly negative angle of attack results in zero lift, so this simple approach has a ready fail-safe condition.

Abstract: A wind turbine blade is configured such that the lift force from the blade airfoil is always normal, or nearly normal, to the shaft torque. This condition maximizes energy conversion. This objective may be achieved by a) having the airfoil chord always aligned to the actual wind direction (subject only to small angle of attack variations), and b) slowing the turbine rotation rate so that no blade twist is needed. As a result, blade tip speed due to shaft rotation is less than the wind speed, and preferably much less. This low tip speed eliminates any hazard to birds. The lift force from the blade airfoil directly drives the torque on the shaft, so the control problem simplifies to adjusting the blade angle of attack to keep the lift constant across varying wind speeds. For most airfoils, a slightly negative angle of attack results in zero lift, so this simple approach has a ready fail-safe condition.

Abstract: A wind turbine blade is configured such that the lift force from the blade airfoil is always normal, or nearly normal, to the shaft torque. This condition maximizes energy conversion. This objective may be achieved by a) having the airfoil chord always aligned to the actual wind direction (subject only to small angle of attack variations), and b) slowing the turbine rotation rate so that no blade twist is needed. As a result, blade tip speed due to shaft rotation is less than the wind speed, and preferably much less. This low tip speed eliminates any hazard to birds. The lift force from the blade airfoil directly drives the torque on the shaft, so the control problem simplifies to adjusting the blade angle of attack to keep the lift constant across varying wind speeds.

Abstract: A wind turbine blade is configured such that the lift force from the blade airfoil is always normal, or nearly normal, to the shaft torque. This condition maximizes energy conversion. This objective may be achieved by a) having the airfoil chord always aligned to the actual wind direction (subject only to small angle of attack variations), and b) slowing the turbine rotation rate so that no blade twist is needed. As a result, blade tip speed due to shaft rotation is less than the wind speed, and preferably much less. This low tip speed eliminates any hazard to birds. The lift force from the blade airfoil directly drives the torque on the shaft, so the control problem simplifies to adjusting the blade angle of attack to keep the lift constant across varying wind speeds.

Abstract: A transmission apparatus has two modes of power amplifier operation, in which mode 1 is inherently accurate, mode 2 is inherently less accurate, and measurement of a power amplifier output from mode 1 is used to correct a power amplifier output in mode 2. Mode 1 may be a compressed mode and mode 2 may be a non-compressed mode. The apparatus may include a power controller that provides overlapping scaling factor sets for modes 1 and 2 and controls transmission power using the scaling factor sets. Upon a mode transition, the controller uses the overlapping scaling factors and changes the scaling factor set for the mode of a destination of the transition based on actual measurement representative of transmission power, for example, by carrying out power alignment loop operations. A cellular mobile device may include such transmission apparatus. A polar modulation transmitter is also disclosed.

Abstract: A transmission apparatus has two modes of power amplifier operation, in which mode 1 is inherently accurate, mode 2 is inherently less accurate, and measurement of a power amplifier output from mode 1 is used to correct a power amplifier output in mode 2. Mode 1 may be a compressed mode and mode 2 may be a non-compressed mode. The apparatus may include a power controller that provides overlapping scaling factor sets for modes 1 and 2 and controls transmission power using the scaling factor sets. Upon a mode transition, the controller uses the overlapping scaling factors and changes the scaling factor set for the mode of a destination of the transition based on actual measurement representative of transmission power, for example, by carrying out power alignment loop operations. A cellular mobile device may include such transmission apparatus. A polar modulation transmitter is also disclosed.

Abstract: A multiple path angle modulator includes a closed secondary loop added to a main control loop to automatically adjust a scaling factor related to high frequency gain. The main control loop is configured as a primary path to process the low frequency portion of the angle modulation signal, and the secondary loop is configured as an auxiliary path to process the high frequency portions of the angle modulation signal. The secondary loop senses calibration information and uses it to continuously calibrate the gain within the modulation loop in real time while the system performs its primary operation, thereby eliminating the need for a system shut down or calibration specific timing, such as a lapse time, to balance the modulation paths. Calibration is continuously performed as a background process.

Abstract: The present invention, generally speaking, provides for high-efficiency power control of an amplifier apparatus. In one example of the present invention, the amplifier apparatus comprises a power control circuit for producing a specified signal using a magnitude signal and a power source in accordance with a control signal, produced independently of the RF input signal and an amplifier that has the specified signal as a supply signal and producing an RF output signal.

Abstract: The present invention, generally speaking, takes advantage of the properties of quadrature signals to achieve precise quadrature alignment in a simple fashion. In particular, the expectation of the product of quadrature signals is zero. In accordance with the teachings of the invention, a phase error detection network therefore operates by multiplying the received quadrature signals and low-pass filtering the product to produce an error signal. When the signals are in precise quadrature relationship, the error signal will be zero. Real-time feedback control may be used to drive the error to zero. In accordance with another aspect of the invention, a variable phase shift network is achieved using a dual delay line. The difference in delay between the two delay lines is adjusted in response to the error signal to obtain precise quadrature alignment. The principles of the invention may be applied in connection with traditional mixer architectures or with switch-mode (e.g., “aliased undersampling”) architectures.

Abstract: Switchmode DC-DC power converters using one or more non-Silicon-based switching transistors and a Silicon-based (e.g. CMOS) controller are disclosed. The non-Silicon-based switching transistors may comprise, but are not necessarily limited to, III-V compound semiconductor devices such as gallium arsenide (GaAs) metal-semiconductor field effect transistors (MESFETs) or heterostructure FETs such as high electron mobility transistors (HEMTs). According to an embodiment of the invention, the low figure of merit (FoM), ?FET, of the non-Silicon-based switching transistors allows the converters of the present invention to be employed in envelope tracking amplifier circuits of wireless devices designed for high-bandwidth technologies such as, for example, EDGE and UMTS, thereby improving the efficiency and battery saving capabilities of the wireless devices.

Abstract: The present invention, generally speaking, achieves noise spreading within a PLL using a dual-modulus prescaler by interleaving the division moduli. Within a given cycle, “ones” and “tens” are not all counted consecutively. Instead, ones and tens are interleaved. In one embodiment of the invention, the R count is doubled and the output of the R counter is toggled between high and low states. (The Q counter may remain unmodified.) In another embodiment of the invention, ones and tens are interleaved in accordance with a ratio q:r. By so interleaving the modulus, the effect is to spread the noise resulting from the output signal of the dual-modulus prescaler over a wider frequency range. The prescaler noise level is greatly reduced, particularly within the frequency band of the reference frequency.

Abstract: The present invention, generally speaking, provides for high-efficiency power control of a high-efficiency (e.g., hard-limiting or switch-mode) power amplifier in such a manner as to achieve a desired modulation. In one embodiment, the spread between a maximum frequency of the desired modulation and the operating frequency of a switch-mode DC-DC converter is reduced by following the switch-mode converter with an active linear regulator. The linear regulator is designed so as to control the operating voltage of the power amplifier with sufficient bandwidth to faithfully reproduce the desired amplitude modulation wave-form. The linear regulator is further designed to reject variations on its input voltage even while the output voltage is changed in response to an applied control signal. This rejection will occur even though the variations on the input voltage are of commensurate or even lower frequency than that of the controlled output variation.

Abstract: The present invention, generally speaking, provides for high-efficiency power control of a high-efficiency (e.g., hard-limiting or switch-mode) power amplifier in such a manner as to achieve a desired modulation. In one embodiment, the spread between a maximum frequency of the desired modulation and the operating frequency of a switch-mode DC-DC converter is reduced by following the switch-mode converter with an active linear regulator. The linear regulator is designed so as to control the operating voltage of the power amplifier with sufficient bandwidth to faithfully reproduce the desired amplitude modulation wave-form. The linear regulator is further designed to reject variations on its input voltage even while the output voltage is changed in response to an applied control signal. This rejection will occur even though the variations on the input voltage are of commensurate or even lower frequency than that of the controlled output variation.

Abstract: Switchmode DC-DC power converters using one or more non-Silicon-based switching transistors and a Silicon-based (e.g. CMOS) controller are disclosed. The non-Silicon-based switching transistors may comprise, but are not necessarily limited to, III-V compound semiconductor devices such as gallium arsenide (GaAs) metal-semiconductor field effect transistors (MESFETs) or heterostructure FETs such as high electron mobility transistors (HEMTs). According to an embodiment of the invention, the low figure of merit (FoM), ?FET, of the non-Silicon-based switching transistors allows the converters of the present invention to be employed in envelope tracking amplifier circuits of wireless devices designed for high-bandwidth technologies such as, for example, EDGE and UMTS, thereby improving the efficiency and battery saving capabilities of the wireless devices.

Abstract: The present invention, generally speaking, provides for high-efficiency power control of a high-efficiency (e.g., hard-limiting or switch-mode) power amplifier in such a manner as to achieve a desired modulation. In one embodiment, the spread between a maximum frequency of the desired modulation and the operating frequency of a switch-mode DC—DC converter is reduced by following the switch-mode converter with an active linear regulator. The linear regulator is designed so as to control the operating voltage of the power amplifier with sufficient bandwidth to faithfully reproduce the desired amplitude modulation wave-form. The linear regulator is further designed to reject variations on its input voltage even while the output voltage is changed in response to an applied control signal. This rejection will occur even though the variations on the input voltage are of commensurate or even lower frequency than that of the controlled output variation.

Abstract: The present invention, generally speaking, provides for high-efficiency power control of a high-efficiency (e.g., hard-limiting or switch-mode) power amplifier in such a manner as to achieve a desired modulation. In one embodiment, the spread between a maximum frequency of the desired modulation and the operating frequency of a switch-mode DC-DC converter is reduced by following the switch-mode converter with an active linear regulator. The linear regulator is designed so as to control the operating voltage of the power amplifier with sufficient bandwidth to faithfully reproduce the desired amplitude modulation wave-form. The linear regulator is further designed to reject variations on its input voltage even while the output voltage is changed in response to an applied control signal. This rejection will occur even though the variations on the input voltage are of commensurate or even lower frequency than that of the controlled output variation.

Abstract: The present invention, generally speaking, provides methods and apparatus for producing an amplitude modulated communications signal, in which a constant-envelope carrier signal is modified in response to a power control signal to produce a modified constant-envelope carrier signal. The modified constant-envelope carrier signal is amplified in response to an amplitude modulation signal to produce a communications signal having amplitude modulation and having an average output power proportional to a signal level of the modified constant-envelope carrier signal. This manner of operation allows wide dynamic range of average output power to be achieved. Because amplitude modulation is applied after amplitude varying circuitry used to produce the modified constant-envelope carrier signal, the amplitude modulation is unaffected by possible non-linearities of such circuitry.

Abstract: The present invention, generally speaking, provides methods and apparatus for producing an amplitude modulated communications signal, in which a constant-envelope carrier signal is modified in response to a power control signal to produce a modified constant-envelope carrier signal. The modified constant-envelope carrier signal is amplified in response to an amplitude modulation signal to produce a communications signal having amplitude modulation and having an average output power proportional to a signal level of the modified constant-envelope carrier signal. This manner of operation allows wide dynamic range of average output power to be achieved. Because amplitude modulation is applied after amplitude varying circuitry used to produce the modified constant-envelope carrier signal, the amplitude modulation is unaffected by possible non-linearities of such circuitry.

Abstract: The present invention, generally speaking, uses multiple selectable power supply paths, a saturation detector, or combinations of the same to achieve efficient power supply processing. In one aspect of the invention, a power supply processing circuit includes a first switched converter stage and a second linear stage. Depending on the power supply desired, the first stage may be bypassed to avoid conversion losses. In another aspect of the invention, a saturation detector is used to control the first stage such that the second stage operates efficiently just short of saturation, thereby avoiding distortion.

Abstract: The present invention, generally speaking, provides a time shift angle demodulator that is of simple construction and has an extended linear range. Range extension is achieved by using the input signals directly, not simply post-processing the S-PFD outputs. In accordance with one embodiment of the invention, a method of measuring the phase or frequency of a periodic input signal uses a periodic reference signal and includes comparing the input signal to the reference signal to obtain a lead signal and a lag signal; changing the count of an up/down counter in dependence on the input signal, the reference signal, the lead signal and the lag signal; and using the lead signal, the lag signal and the count signal to produce a phase or frequency signal.