Abstract:
A direct digital synthesizer (DDS) ( 300 ) that uses a system for reducing spurious emissions in a digital-to-time converter (DTC) ( 317 ). The DDS ( 300 ) includes one or more dither sources ( 307 ) and a random access memory (RAM) ( 305 ). The RAM ( 305 ) utilizes a look-up table for storing delay error values by using an output of the look-up table which is combined with the dither source ( 307 ) to compensate unequal unit delay values in the DTC ( 317 ).
Abstract:
A communication device 200 capable of operating in a communication system 100 having a control system which generates information signals with redundant information is disclosed. The communication device comprises: a receiver 214 for receiving the information signals; a circuit which can determine the signal quality of the received information signals 234; and a controller 226 which decodes the received information signals, and further compares the signal quality of the information signals with a predetermined value, and decides if the received signal quality is at least equal to the predetermined value in order to only decode a portion of the information signal. Upon the communication device decoding a portion of the information signal, the communication device 200 is placed in a battery saving mode in order to conserve battery life.
Abstract:
Improvement of quantization errors that arise in a delay line with finite resolution. A direct digital synthesizer (DDS), which contains a numerically controlled oscillator (NCO) and a digital-to-phase converter (DPC), is placed in the feedback loop of a phase locked loop (PLL). The DDS is used as a fractional divider of the voltage controlled oscillator (VCO) frequency, such that the reference frequency of the DDS is made variable. Alignment of the edges provided by the DDS delay line may then be adjusted. Mismatch errors in the DDS delay line are reduced by utilizing independently tunable delay elements.
Abstract:
A configurable circuit consistent with certain embodiments has a variable length delay line (10), the delay line (10) having an input (24) and having N delay elements (12, 14, 16, 18,…, 20) to provide a plurality of N delayed outputs (T(0) through T(N)). The variable length delay line (10) also has a number of active delay elements determined by a program command. A configurable processing array (32) receives the delayed outputs from the active delay elements and secondary data (38). The configurable processing array has an array of configurable circuit elements (104, 130, 150). The configurable processing array is configured to process the delayed outputs and the secondary data (38) in a manner for which the invention is to be used. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.
Abstract:
A direct digital synthesizer (30) with noise shaping circuitry can comprise a ROM-less direct digital synthesizer having a quantizer (40) and a noise shaping loop incorporating the quantizer for shaping a quantization noise due to noise from the quantizer. The noise shaping loop can comprise a noise shaping filter (44) and the noise shaping loop can feed back to the noise shaping filter a difference between an input signal (49) to the quantizer and an output signal (43) from the quantizer. The ROM-less direct digital synthesizer can further include a dither (39) combined at an input of the quantizer.
Abstract:
A delay locked loop circuit (200) in which multiple outputs are produced. A single delay line (24) is shared among multiple tap selection circuits (256A, 265B, 265C). Fixed phase shifts (412) can be introduced between multiple outputs. A modulating signal can be used in the tap selection processing to produce digital amplitude, frequency and/or phase modulation.
Abstract:
A system and a method for providing an input to a distributed power amplifying system are provided. In an embodiment, a distributed power amplifying system includes a plurality of amplifying sections (102, 104, 106, and 108) and a plurality of drivers (110, 112, 114, and 116). Each of the plurality of drivers receives a common transmit signal (118) and an individual control signal (120, 122, 124, and 126). Each of the plurality of drivers independently preconditions the common transmit signal, to provide a transmit output signal (128, 130, 132, and 134) to each of the plurality of amplifying sections. The common transmit signal provided to each of the plurality of drivers is preconditioned, based on the individual control signal.
Abstract:
A delay locked loop frequency synthesizer in several embodiments uses a primary delay line element (24) and one or more secondary delay elements (162 164, 270, 310). In one embodiment, a main delay line (24) is used to coarsely select a frequency output while a secondary delay element (162 164, 270, 310), either passive or active, is used to increase the resolution of the primary delay line (24). In the passive embodiment, a coarse and fine frequency selection is possible by selecting components from the output taps of the main delay line (24) as a driving signal for the passive secondary delay element (310) to provide the coarse adjustment and selecting an output from the secondary delay element (310) to provide the fine selection.
Abstract:
A reconfigurable processor circuit (200) consistent with certain embodiments of the present invention has an array of configurable circuit blocks, wherein certain of the configurable circuit blocks comprise one of configurable arithmetic logic units and clocked digital logic circuits. A control processor (218) configures a function of a plurality of the configurable circuit blocks. A memory (224) stores program instructions used by the control processor (218). A multiple frequency generator (212) receives a reference clock and synthesizes the plurality of clock signals therefrom, each clock signal being configured in frequency by the control processor (218). A timing control circuit (236) receives the plurality of clock signals, allocates the plurality of clock signals of different frequency among the plurality of circuit blocks and routes the clock signals to the circuit blocks, wherein the timing control circuit (236) operates under control of the control processor (218).
Abstract:
A feedforward amplifier and notch filter (150) according to the present invention uses a direct coupling of an amplifier stage (158) with the amplifier's load (RL). The main amplifier (202) is coupled through a transmission line (210) to the load. This direct coupled amplifier stage (158) is driven by an signal that induces a very low impedance in parallel with the load at the receive frequency, but appears as an open circuit at the desired frequencies so that the desired signal from the main amplifier is virtually unaffected while output components at the receive frequency are cancelled.