Active control of interference is necessary with increased cell density, more complicated environmental reflections, and coexistence of multiple networks for next-generation wireless communications. The existing radio receiver architectures for spatial interference cancellation (SpICa) are limited by the spatial nulls created by a phased-antenna array (PAA) and cannot cover wide modulated bandwidths (BWs). We propose a discrete-time-delay-compensating technique for canceling spatial interferences with wide modulated BWs to reduce the dynamic range requirement for the data converter. Integral to the proposed circuit is a switched-capacitor-based multiply-and-accumulate processor that incorporates a reconfigurable phase interpolator and time interleaver for precise digitally tunable delays and multiplication of the input signal to an orthogonal matrix. The digital time interleaver enables 5-ps resolution with a reconfigurable range up to 15 ns. The measured results demonstrate greater than 35-dB SpICa over 80-MHz modulated BWs in the 65-nm CMOS with 52 mW of power consumption.
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A 345μW 1GHz Process and Temperature Invariant Constant Slope-and-Swing Ramp-based 7-bit Phase Interpolator for True-Time-Delay Spatial Signal Processors
In the baseband time delay (TD) elements used
for delay compensation in discrete-time beamformers, phase
interpolator (PI) plays a crucial role as the resolution of the PI
defines the delay resolution of the TD. In this paper, we present
a process and temperature invariant high-resolution and highly
linear low-power PI. The proposed PI uses current integration
which generates an adaptable constant slope-and-swing ramp
signal to achieve low power. By switched-capacitor bias
generation, the PI linearity is enhanced with 0.2 LSB DNL and
0.3 LSB INL, respectively. The 7-bit PI is realized in 65nm CMOS
technology can generate the full range delay with a resolution
of 8psec with the input of 1GHz. The PI consumes a power of
345μW and occupies an active area of 0.021mm2.
Keywords—Ramp-rate tracking, constant slope-and-swing,
phase interpolator, ramp-based, baseband time delay
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- Award ID(s):
- 2030159
- NSF-PAR ID:
- 10351767
- Date Published:
- Journal Name:
- IEEE Radio Frequency Integrated Circuits Symposium
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
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