Abstract:
An apparatus and method for eliminating unwanted signal power dissipation in balanced amplifier circuits and for prohibiting unwanted signal power from appearing at the balanced amplifier load is presented. Load impedances to the amplifier power output transistors are maintained very low at unwanted frequencies, and are at an operational impedance level at the fundamental frequency. An impedance network control concept is presented, which may be either manually or automatically implemented.
Abstract:
A signal generator consistent with certain embodiments of the invention has a reference clock (34) producing a periodic sequence of reference clock output pulses. A window generator (38) generates a plurality of time windows through which a selected plurality of the reference clock output pulses are selectively passed as windowed pulses so that the windowed pulses form a selected pattern of pulses. A programmable delay (46) has resolution of delay that has finer time granularity in delay than the period of the clock output pulses. The programmable delay (46) delays each of the windowed pulses by a programmed delay time to thereby provide a timing correction to the windowed pulses to produce an output pattern of pulses.
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 DPC (300) includes: a frequency source (310) for generating a clock signal; a delay line (320) for receiving the clock signal and generating phase-shifted clock signals at output taps; a digital control device (330) for generating a control signal; and a windowing and selection circuit for generating the output signal, that includes sequential logic devices (500, 510, 520) and a combining network. A method for use in a DPC includes: receiving (400) a control signal based on a desired output signal that identifies a first output tap on the delay line; based on the control signal, selecting (410) at least two output taps on the delay line for receiving at least two different phase-shifted clock signals; and generating (420) an output signal based on the control signal and the received phase-shifted clock signals that is substantially the desired output signal.
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 frequency extension circuit, consistent with certain embodiments of the present invention has a first delay line (108) having a plurality of taps. The delay line receives a reference clock at an input with a clock rate of FREF. A second delay line (104, 150) also receives the reference clock at an input. A logic circuit (130, 134, …, 138, 140) combines signals from the delay line taps of the first delay line (108) with signals from the delay line taps of the second and/or first delay line (104, 150, 108) to produce a collection of clock pulses having a combined clock rate of FREF*2N. At least one of the delay lines can be locked to the reference clock using a delay locked loop. The clock pulses can be logically combined with a seed register (204) contents to produce a recursive sequence or with data for convolutional encoding, or with pilot data for correlation in a CDMA transceiver.
Abstract:
A method and system for managing Digital to Time Conversion (DTC) is provided. The method comprises receiving a first Radio Frequency (RF) signal and a second RF signal. The second RF signal is a phase-shifted first RF signal. The method further comprises converting the first RF signal to a first Intermediate Frequency (IF) signal and the second RF signal to a second IF signal. Further, a time delay between the first IF signal and the second IF signal is estimated based on a time difference measurement technique. The second RF signal is processed based on the estimated time delay to compensate for a delay error associated with the second RF signal.
Abstract:
A delay-locked loop 300 that includes: an adjustable frequency source (320) for generating a clock signal (322) having an adjustable frequency; an adjustment and tap selection controller (310) for determining a first frequency as a function of a second frequency and for causing the frequency source to adjust the frequency of the clock signal to substantially the first frequency, the second frequency being the desired frequency of a first output signal; a delay line (330) configured to receive the clock signal for generating a plurality of phase-shifted clock signals; and a first selection circuit (370) for receiving the plurality of phase-shifted clock signals and for selecting, one at a time and under the control of the adjustment and tap selection controller, a first sequence of the phase-shifted clock signals for generating the first output signal having substantially the second frequency.
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.