Data Sheet

K-MC4 MONOPULSE RADAR TRANSCEIVER Datasheet
Rapid Sleep Wakeup (RSW)
RFbeam's unique rapid sleep wakeup feature allows power savings of more than 90% during 'silent'
periods. The module may be used in a relaxed sampling mode as long as no movements are
detected. RSW also helps saving power, if the full IF bandwidth is not needed.
In battery operated equipment such as traffic control, RSW may significantly lower battery and
equipment volume and cost.
RSW Principle
K-MC4 contains a high speed variant of RSW without internal S&H device. RSW combines switching
of the RF oscillator and an isolation of the following IF amplifier (please refer to Fig. 1: K-MC4
Blockdiagram). During sleep mode (pin /ENABLE = high), only the amplifiers stay supplied to hold the
output center voltage.
IF output signals are active, as soon as /Enable is low, otherwise IF outputs fall back to their DC level
which is Vcc/2.
Fig. 8: Sampled Doppler signal (1.3kHz) at IF I or Q outputs
T
s
= t
on
+ t
off
t
on
min = 5µs
t
OFF
max = 2ms
duty cycle d = 100* t
on
/ T
s
> 0.25%
Example for calculationg power saving:
Max object speed to detect = 200km/h
-> f
doppler
= 200km/h * 44Hz = 8.8kHz
-> f
s
= 20kHz to meet Nyquist criteria
-> T
s
= 1/f
s
= 50us
-> d = 100% * 5µs/50us = 10%
Note: With undersampling during silent periods,
much more power saving is possible
Fig. 9: Detailed RSW sampling behaviour
© RFbeam Microwave GmbH, Schuppisstrasse 7, CH-9016 St. Gallen Page 8/14
200us/div
IF Output (DC-level = 2.5V)
/Enable
50us/div
/
Enable
IF Output
Zoomed
IF
50us/div
/Enable
IF Output
Zoomed IF
t
on
t
off
Ts