# 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.
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bevans@ece.utexas.edu