4-2019

RF & Wireless
Record-Breaking Ringamp ADCs
Imec presents a compact, highly linear 3.2 gigasample-per-second
(GSps) RF-sampling ADC that
uses ring amplification (ringamp). The ADC has a
record low power consumption of 61.3 mW and
supports multiband operation and massive MIMO
implementation – two key features of future 5G
base stations. A second power-efficient ringampbased
ADC – reconfigurable between 6 and 600
Msps – was developed for mobile handsets.
Key performance merits of the 3.2 GSps RFsampling
ADC are its excellent spectral purity in
combination with a record low power consumption
of 61.3 mW – a factor 10 improvement compared
with state-of-the-art-technology. The high
sensitivity and linearity are demonstrated by the
ADC’s Nyquist signal-to-noise-and-distortion
ratio (SNDR) of 61.7 dB and by its spurious free
dynamic range (SFDR) of 73.3 dB. The device is
fabricated in 16 nm CMOS technology and occupies
an active area of only 0.194 mm 2 (360 x 540
µm). With these record-breaking specifications,
two main challenges for future 5G base station
ADCs are addressed.
With current base station radios – typically implemented
with a zero-IF architecture – multiband
operation can only be achieved by implementing
an increasing number of transceivers. This significantly
contributes to the area and power consumption
of the base station. With sampling speeds in
the GHz realm, imec’s new ADC allows the development
of compact radios that combine multiple
bands for cellular infrastructure applications, at
much lower power consumption.
Moreover, the large-scale antenna arrays required
for MIMO operation are implemented by using a
large number of power-hungry discrete transceivers.
Our RF-sampling ADC fabricated in scaled
process technologies, enables massive-MIMO
implementation as a System-on-Chip at much
lower power consumption and significantly reduced
Bill-of-Materials.
At the heart of imec’s RF-sampling ADC is a
ringamp-based pipelined architecture. This new
amplifier topology offers excellent speed and
power efficiency in scaled FinFET technology,
allowing fast and accurate settling of large capacitive
loads over near-maximum voltage swings in
a low supply voltage. It has been combined with
a new event-driven approach to timing control in
the pipelined ADC architectures that allows for
fully dynamic operation of the ADC, where the
active blocks only consume power proportional
to clock speed.
■ Imec, www.imec.be
Sub-mW Radar for Presence
Detection
Imec announced an exceptional radar transceiver
designed as an efficient, low-cost solution for presence
detection in smart building solutions. The
power consumption of the radar is below 1 mW,
which is 100 times lower than other solutions, and
is capable of detecting even micro-movements
from human respiration, up to a distance of 15 m.
This performance makes it a breakthrough solution
for low-cost battery-powered presence-detection
and people counting applications.
Similar as camera, radar can build a picture of
its environment. While cameras are especially
good at 2D images, radar is superior in detecting
movement and distance. Consequently, it is a perfect
fit with human motion and activity detection.
In many circumstances, radar sensors are better
suited than cameras for presence detection, people
tracking or activity classification. That is for
example the case when privacy considerations
are key, such as in office spaces, hotel rooms, or
hospitals. Another advantage is their robustness
to suboptimal light conditions. Different from
camera, radar can robustly detect micro-movements
due to respiration or heartbeat. However,
current commercial radars use too much power,
and often require more expensive semiconductor
technologies. This makes them unsuited for lowcost
and battery-powered operation. Imec’s new
transceiver has been specifically designed with
these requirements in mind.
The new transceiver is compliant with FCC and
ETSI spectral regulations for the UWB frequency
range, limiting the radiation to -41 dBm/MHz.
This energy density is well below the noise floor
of mainstream commercial systems, and therefore,
this radar can safely be used for 24/7 people
presence detection without health concerns.
The power consumption of the transciever IC is
less than 1 mW, at least 100 times less than comparable
state-of-the-art solutions. With that, it is
able to discern movements and vital signs – breathing
and heartbeats – up to 15 m, which is a
record for UWB radars.
■ Imec, www.imec.be
hf-Praxis
ISSN 1614-743X
Fachzeitschrift
für HF- und
Mikrowellentechnik
• Herausgeber und Verlag:
beam-Verlag
Krummbogen 14
35039 Marburg
Tel.: 06421/9614-0
Fax: 06421/9614-23
info@beam-verlag.de
www.beam-verlag.de
• Redaktion:
Dipl.-Ing. Reinhard Birchel
Ing. Frank Sichla (FS)
redaktion@beam-verlag.de
• Anzeigen:
Myrjam Weide
Tel.: +49-6421/9614-16
m.weide@beam-verlag.de
• Erscheinungsweise:
monatlich
• Satz und Reproduktionen:
beam-Verlag
• Druck & Auslieferung:
Brühlsche
Universitätsdruckerei
Der beam-Verlag übernimmt
trotz sorgsamer Prüfung der
Texte durch die Redaktion
keine Haftung für deren
inhaltliche Richtigkeit. Alle
Angaben im Einkaufsführer
beruhen auf Kundenangaben!
Handels- und Gebrauchsnamen,
sowie
Warenbezeichnungen
und dergleichen werden
in der Zeitschrift ohne
Kennzeichnungen verwendet.
Dies berechtigt nicht
zu der Annahme, dass
diese Namen im Sinne
der Warenzeichen- und
Markenschutzgesetzgebung
als frei zu betrachten sind
und von jedermann ohne
Kennzeichnung verwendet
werden dürfen.
78 hf-praxis 4/2019