ECE 445S Real-Time Digital Signal Processing Laboratory - Lecture 10 - Announcements

Prof. Brian L. Evans

Announcements: Power Consumption in 5G Data Converters

Here is the power consumption for subsystems in an analog/RF front end for a wireless communication system using 28 GHz RF communications with a transmission bandwidth of 850 MHz [1]. The following components in each analog/RF front end do not increase in power consumption vs. bandwidth [1]:

39mW Low Noise Amplifier
17mW Mixer
 5mW Local Oscillator
14mW Lowpass Filter
 5mW Baseband Amplifier

The remaining power consumption budget can be put into the data converters [2]. nalog-to-digital converter (ADC) power consumption increases linearly or quadratically with the sampling rate and exponentially in the number of bits [3].

Here are two example standalone IC chips:

6.6W dual-channel (IQ) ADC, 3 GHz sampling rate, 12 bits per channel [4] and can capture entire 850 MHz band
3.8W dual-channel (IQ) ADC, 1.25 GHz sampling rate, 14 bits per channel [5] but can only capture part of 850 MHz band

Knowing that the power consumption is proportional to 2^bits, a 1-bit version of each of the above converters would need

3.22mW dual-channel (IQ) ADC, 3 GHz sampling rate, 1 bit per channel and can capture entire 850 MHz band
0.46mW dual-channel (IQ) ADC, 1.25 GHz sampling rate, 1 bit per channel but can only capture part of 850 MHz band

The power consumption would double for every extra bit per channel added.

References

[1] W. B. Abbas, F. Gomez-Cuba, and M. Zorzi, "Millimeter Wave Receiver Efficiency: A Comprehensive Comparison of Beamforming Schemes With Low Resolution", IEEE Transactions on Wireless Communications, vol. 16, no. 12, Dec. 2017, pp. 8131-8146.
[2] O. Orhan, E. Erkip, and S. Rangan, "Low Power Analog-to-Digital Conversion in Millimeter Wave Systems: Impact of Resolution and Bandwidth on Performance", Proc. IEEE Information Theory and Applications Workshop, 2015.
[3] B. Murmann, A/D Converter Figures of Merit and Performance Trends, April 28, 2017.
[4] Texas Instruments, ADC32RF45 Data Sheet, Dec. 2016, p. 116.
[5] Analog Devices, AD9691 Data Sheet, 2015.

Last updated 06/07/22. Send comments to (Mailbox) bevans@ece.utexas.edu