Digital-to-analog converter with localized frequency multiplication circuits
AssigneeApple Inc.
InventorAntonio Passamani
Life of this patent
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Abstract
The current disclosure is related to digital-to-analog converters (DACs) with localized frequency multiplication circuits. For example, an electronic device may include a local oscillator (LO) providing clock signals, a digital front-end providing digital signals, a DAC, (e.g., a radio frequency DAC (RFDAC)), and one or more antennas. The DAC may include a number of cells (e.g., unit power amplifiers). Moreover, each cell may provide a unit power analog signal upon activation with a higher frequency than the received digital signals and clock signals. The DAC may provide an output signal (e.g., an analog signal) based on combining (e.g., aggregating) the unit power analog signals of the activated cells for transmission by the one or more antennas.
Claims20
A radio frequency (RF) transmitter comprising:
- a local oscillator (LO) configured to output a LO signal with a first frequency;
- and
- a digital-to-analog converter (DAC) coupled to the LO, the DAC receiving the LO signal from the LO, the DAC comprising a plurality of cells, each cell of the plurality of cells comprising first frequency multiplication circuitry and a capacitor, and each cell of the plurality of cells configured to
- receive the LO signal having the first frequency,
- receive a bitstream having the first frequency, and
- output an analog signal corresponding to the bitstream with a second frequency based on combining a portion of a voltage of the bitstream, a portion of a voltage of an inverted bitstream that is based on the bitstream, and the LO signal, the second frequency being greater than the first frequency.
An electronic device comprising:
- a processor configured to generate a bitstream with a first frequency, the bitstream corresponding to a transmission signal;
- one or more antennas configured to transmit the transmission signal;
- and
- a transmitter comprising a digital-to-analog converter (DAC) coupled to the processor, the DAC configured to
- receive a local oscillator (LO) signal from an LO,
- receive the bitstream from the processor, and
- output an analog signal corresponding to the transmission signal based on combining a portion of a voltage of the bitstream, a portion of a voltage of an inverted bitstream that is based on the bitstream, and the LO signal, the analog signal having a second frequency greater than the first frequency.
A method comprising
- receiving, by a processor of an electronic device, an indication to transmit a transmission signal with a first frequency;
- providing, by the processor, one or more control signals to a digital-to-analog converter (DAC), the one or more control signals configured to select a frequency multiplication factor of the DAC for generating the transmission signal;
- and
- providing, by the processor, a bitstream with a second frequency to the DAC to cause the DAC to output an analog signal corresponding to the transmission signal based on combining a portion of a voltage of the bitstream, a portion of a voltage of an inverted bitstream that is based on the bitstream, and a local oscillator (LO) signal, the analog signal having the first frequency, and the second frequency being a fraction of the first frequency based on the frequency multiplication factor.
Dependencies are inferred from the claim text.