Data Sheet

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RFbeam Microwave GmbH | Schuppisstrasse 7 | CH-9016 St. Gallen | www.rfbeam.ch | K-LD 2 | data sheet 02 / 2020 – Revision C | Page 6 / 25
Overview
The K-LD2 takes advantage of an internal I/Q doppler
signal processing by using a complex FFT ( Fast Fou-
rier Transform ). The main advantages of this proces-
sing compared to standard time domain processing
solutions are the following:
– Easy detection of the direction of a movement
– Increased detection range with better SNR
duetotheFFT processing
– Efficient interference suppression
– Vibration suppression
Sampling & FFT calculation
– I / Q channel
– Configurable sample rate
– 256 point complex FFT
Threshold generation
– Adaptive noise measurement
– Interference suppression
– Depending on sensitivity setting
Detection algorithm
– Search for valid detection
– Direction, speed&magnitude
calculation
– Latch detection for the length
of the hold time setting
Figure 4: Signal processing anddetection workflow
With a powerful command set (See chapter Command
Set Description) it is possible to configure thewhole
signal processing and detection workflow. This allows
customisation of the K-LD2 to get thebest results in
different environments and applications.
THEORY OF OPERATION
The signal processing unit samples the analogue
I/Qdoppler signals of the RF frontend and calculates
a complex FFT in real time. In a next step an adap-
tive noise measurement and interference suppression
isdone which generates a threshold limit that can be
adjusted with the sensitivity setting. Then the detection
algorithm looks for a valid detection and latches itto
the detection register and the digital outputs for the
length of the hold time setting.