摘要:
A transmitter employing a sigma delta modulator having a noise transfer function adapted to shift quantization noise outside at least one frequency band of interest. A technique is presented to synthesize the controllers within a single-loop sigma delta modulator such that the noise transfer function can be chosen arbitrarily from a family of functions satisfying certain conditions. Using the novel modulator design technique, polar and Cartesian (i.e. quadrature) transmitter structures are supported. A transmitter employing polar transmit modulation is presented that shapes the spectral emissions of the digitally-controlled power amplifier such that they are significantly and sufficiently attenuated in one or more desired frequency bands. Similarly, a transmitter employing Cartesian transmit modulation is presented that shapes the spectral emissions of a hybrid power amplifier such that they are significantly and sufficiently attenuated in one or more desired frequency bands.
摘要:
A novel apparatus for and a method of estimating, calibrating and tracking in real-time the gain of a radio frequency (RF) digitally controlled oscillator (DCO) in an all-digital phase locked loop (ADPLL). Precise setting of the inverse DCO gain in the ADPLL modulating path allows direct wideband frequency modulation that is independent of the ADPLL loop bandwidth. The gain calibration technique is based on a steepest descent iterative algorithm wherein the phase ADPLL error is sampled and correlated with the modulating data to generate a gradient. The gradient is then scaled and added to the current value of the DCO gain multiplier.
摘要:
System and method for interfacing with a digital computer using a multi-function device. A preferred embodiment comprises a multi-function device comprising a controller configured to process information and regulate operations of the multi-function device, a sensor coupled to the controller, the sensor configured to capture information in a movement of the multi-function device or a movement of an object applied to the multi-function device and to provide the information to the controller, wherein the information is used to determine movement information. The multi-function device further comprises a radio frequency circuit also coupled to the controller, the radio frequency circuit is configured to exchange information with other devices via a plurality of communications networks, wherein one of the other devices is a computer and the information shared is movement information from the multi-function device.
摘要:
A novel apparatus and method for a hybrid Cartesian/polar digital QAM modulator. The hybrid technique of the present invention utilizes a combination of an all digital phase locked loop (ADPLL) that features a wideband frequency modulation capability and a digitally controlled power amplifier (DPA) that features interpolation between 90 degree spaced quadrature phases. This structure is capable of performing either a polar operation or a Cartesian operation and can dynamically switch between them depending on the instantaneous value of a metric measured by a thresholder/router. In this manner, the disadvantages of each modulation technique are avoided while the benefits of each are exploited.
摘要:
A novel apparatus and method for a fully digital quadrature architecture for a complex modulator. The complex modulator can substitute for existing prior art analog quadrature modulator structures and those based on a digital polar architecture (r, θ). The modulator effectively operates as a complex digital-to-analog converter where the digital inputs are given in Cartesian form, namely I and Q representing the complex number I+jQ, while the output is a modulated RF signal having a corresponding amplitude and phase shift. The phase shift being with respect to a reference phase dictated by the local oscillator, which is also input to the converter/modulator. Several embodiments are provided including modulators incorporating dual I and Q transistor arrays, a single shared I/Q transistor array, modulators with single ended and differential outputs and modulators with single and dual polarity clock and I/Q data signals.
摘要:
A novel apparatus for and a method of estimating, calibrating and tracking in real-time the gain of a radio frequency (RF) digitally controlled oscillator (DCO) in an all-digital phase locked loop (ADPLL). Precise setting of the inverse DCO gain in the ADPLL modulating path allows direct wideband frequency modulation that is independent of the ADPLL loop bandwidth. The gain calibration technique is based on a steepest descent iterative algorithm wherein the phase ADPLL error is sampled and correlated with the modulating data to generate a gradient. The gradient is then scaled and added to the current value of the DCO gain multiplier.
摘要:
An on-chip receiver sensitivity test mechanism for use in an integrated RF transmitter wherein the transmitter and the receiver share the same oscillator. The mechanism obviates the need to use expensive RF signal generator test equipment with built-in modulation capability and instead permits the use of very low cost external RF test equipment. The invention utilizes circuitry already existing in the transceiver, namely the modulation circuitry and local oscillators to perform sensitivity testing. The on-chip LO is used to generate the modulated test signal that otherwise would need to be provided by expensive external RF test equipment with modulation capability. The modulated LO signal is mixed with an externally generated unmodulated CW RF signal to generate a modulated signal at IF which is subsequently processed by the remainder of the receiver chain. The recovered data bits are compared using an on-chip BER meter or counter and a BER reading is generated. The BER reading is used either externally or by an on-chip processor or controller to establish a pass/fail indication for the chip.
摘要:
An on-chip test mechanism for transceiver power amplifier and oscillator frequency for use with the transmitter portion of an integrated RF transceiver. The RF output from the power amplifier in the transmitter is input to a built-in dedicated analog comparator having a configurable threshold. The threshold is adjusted to a predetermined level at which crossings start to occur at the comparator output. The comparator outputs pulses only if the power amplifier output is above a minimum configurable level. The comparator output is input to a frequency divider whose frequency output is tested by a low cost external tester to determine the actual RF frequency thereby confirming generation of the correct oscillator frequency and that the amplitude of the signal at the output of the power amplifier is sufficiently high for the configurable threshold level to be exceeded, thereby determining the compliance of the output power with its defined specifications.
摘要:
A nonlinear adaptive mechanism for amplitude adjustment and DC estimation and compensation for use in a digital receiver such as a Bluetooth GFSK receiver. The mechanism uses a feed-forward technique that can be used in a multi-stage scheme to perform both DC compensation and amplitude adjustment of an input signal for use by subsequent processing stages. In a first stage, coarse DC offset compensation is performed and the offset estimates generated are subsequently frozen. In a second stage, the incoming signal with the DC offset subtracted from it, is then scaled into a narrow predefined range of amplitudes using a scaling mechanism that works with gains and attenuations that are powers of two in order to simplify implementation. In a third stage, the scaled compensated signal is then injected again into the same DC estimation mechanism, which was previously used for DC compensation in the first stage, for further DC offset estimation and compensation (i.e. fine DC estimation and compensation).
摘要:
A system and method for wireless communication between two devices allows the transfer of location information through a cellular or “BLUETOOTH” link that can be used to provide a continuous indication of estimated distance and direction relative to the two devices in communication with one another.