Can a multi band transmitter be implemented with a RF DAC?
Thus, a multiple band transmitter could be implemented with an RF DAC, an output filter between the DAC and power amplifier, a power amplifier, and output filters between the power amplifier and the antenna.
Is the main DAC clock a differential signal?
The main DAC clock is one of the most critical signals on the system card. The DAC clock is a differential signal and is isolated from other signals via fences. In addition, return paths are controlled to ensure no coupling or crosstalk. Any signals coupling onto the clock will directly appear at the output of the DAC.
What is the role of the DAC in a channel card?
Within a channel card, the DAC acts as the interface between the digital logic and the RF analog output driving network. The DAC plays an important role in the system as its performance, sample rate, and bandwidth all influence the system architecture and design.
How does the DAC affect the signal chain?
In traditional architectures, the overall noise figure of the transmit signal chain is typically dominated by the modulator noise since the noise contributed by the DAC at the modulator output is usually lower than the modulator’s output referred noise floor.
How does an IQ modulator convert RF signals?
An IQ modulator is a device that converts baseband information into RF signals. Internally, two double-balanced mixers are combined as shown below. By modulating with both in-phase (I) and quadrature (Q) inputs, any arbitrary output amplitude and phase can be selected.
How does digital interpolation affect DAC clock frequency?
Digital interpolation is used to increase the DAC clock frequency, and hence the DAC image frequencies. This lowers the filter order requirement of the LC reconstruct filter, which serves to attenuate DAC images to acceptable levels, while minimizing phase error and wideband noise.