Data Sheet

ManualsBrandsRFbeam Microwave ManualsElectronics24GHz digital radar transceiver

– Small and low cost digital 24 GHz radar motion detector

– Detection distance up to 15m (human) 30m (cars)

– High immunity against interferences

– Integrated FFT signal processing with digital outputs

– Sensitivity and hold time can be set using analogue inputs

– Advanced detection data read-out over serial interface

– Wide power supply range from 3.2 to 5.5V

– 2 × 4 patch antenna with 80° / 34° beam aperture

– General movement detection applications

– Door opener

– Illumination of advertising boards

– Touch free switches

– Security systems

– Indoor and outdoor lighting control applications

– Object speed measurement systems

– Industrial sensors

The K-LD2 is a fully digital and low cost radar movement detector.

The digital structure makes it very easy to use in any stand-alone

or MCU based application where a movement detection or speed

measurement is required.

The sensor includes a 2 × 4 patch radar front-end with an asymme

trical beam and a powerful signal processing unit with two digital

outputs for signal detection information. The sensitivity andthe hold

time are adjustable using analogue inputs with potentiometers. The

serial interface features a powerful command set to read-out advan

ced detection data or to fully customize thedetection algorithm.

There is no need to write own signal processing algorithms or

handle small and noisy signals. This module contains every thing

that isnecessary to build a simple, yet reliable movement detector.

A very small footprint of 25 × 25 × 6.5 mm gives maximum ﬂexibility

in the product development process.

A powerful evaluation kit (K-LD2-EVAL) with signal visualization

onaPC is available.

Features

Applications

Description

DATA SHEET

K-LD 2

radar transceiver

Figure 1: K-LD2 block diagram

signal processing unit

voltage regulator

detect

miscellaneous

serial interface

sensitivity hold time

24.125 GHz

K-LD2

Block Diagram

PRODUCT INFORMATION

Summary of content (25 pages)

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D ATA S H E E T K-LD 2 radar transceiver Features –– –– –– –– –– –– –– –– Small and low cost digital 24 GHz radar motion detector Detection distance up to 15m (human) 30m (cars) High immunity against interferences Integrated FFT signal processing with digital outputs Sensitivity and hold time can be set using analogue inputs Advanced detection data read-out over serial interface Wide power supply range from 3.2 to 5.
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CHARACTERISTICS Parameter Conditions / Notes Symbol Min Typ Max Unit Operating Conditions Supply voltage Vcc RMS current IRMS 55 Peak current Ipeak 65 Operating temperature Top -20 +85 °C Tst -20 +105 °C RH 10 90 % 24.050 24.250 GHz Storage temperature Relative humidity Non-condensing, given by design 3.2 5.5 V mA mA Transmitter Transmitter frequency Tamb = -20 ° C .. + 85 ° C fTX Frequency drift vs temperature Vcc = 3.3 V ∆ fTX 0.
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TA B L E O F Product Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Features. CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Applications. . Description. . 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Characteristics. . . . . . . .
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TA B L E O F Integrators Information. . . . . . . . . . . . . . . . . . . . . . . 21 Installation Instruction. . CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . United States (FCC) and Canada (ISED). Europe (CE-RED). 21 . . . . . . . . . . . 22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Outline Dimensions.. . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Order Information.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Revision History. .
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ANTENNA DIAGRAM CHARACTERISTICS This diagram shows module sensitivity (output voltage) in both azimuth and elevation directions. It incorporates the transmitter and receiver antenna characteristics. Figure 2: Antenna characteristics System diagram 350° 340° 330° 0° 0 10° 80° 20° 30° -10 320° 40° -20 310° 50° -30 300° 60° 34° -40 290° 70° -50 280° 80° -60 -70 270° 90° 260° 100° 250° 110° 240° 120° 230° ere ausdrückliche Genehmigung egeben werden.
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T H E O R Y O F O P E R AT I O N Overview The K-LD2 takes advantage of an internal I/Q doppler signal processing by using a complex FFT ( Fast Fourier Transform ).
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Sampling and FFT calculation The K-LD2 works with an internal I/Q doppler signal sampling and a computation of a 256 point wide complex FFT. I/Q doppler signals are phase s hifted by + 90° or - 90° depending on the direction of a movement in the front of the sensor. The signal processing unit samples the I/Q data with a configurable sampling rate (see parameter S04) and computes a complex FFT.
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Figure 6: Doppler signals in the frequency domain, approaching Figure 7: Doppler signals in the frequency domain, receding © RFbeam Microwave GmbH | Schuppisstrasse 7 | CH-9016 St. Gallen | www.rfbeam.
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Start up time During start up, the sensor calculates the mean over the number of FFT frames specified with the para meter start up learn. The start up time of the sensor depends on this parameter, the sampling frequency and the FFT size. tStartup = NFFT · NValue of S05 ƒSample = 256 ∙ NValue of S05 ƒSample Threshold generation The calculated mean during start up represents the noise floor of the sensor and is stored as spectrum average. During operation the spectrum average is adapted continuously.
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Detection algorithm Reaction Time The detection algorithm uses the following steps: The reaction time of the sensor depends on different settings and can be calculated with the equation below when the FFT average feature is disabled. 1. Scan the FFT spectrum for peaks with a magnitude higher than the set threshold level and with the direction to detect set with the parameter D03. 2. Check if the peak is a valid movement with the correct direction or if it is an interference. 3.
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A P P L I C AT I O N I N F O R M AT I O N Stand-alone Operation Host driven Operation With the factory settings the sensor starts up and scans the beam for potential movements with a sampling rate of 2560Hz (app. 0.3 to 29.1 km/h). It filters out interferences and looks for movements with a magnitude that is higher than the threshold level set with the sensitivity.
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Speed limitation and ranging The K-LD2 features the possibility to easily filter out slow and fast speeds by setting speed limits with the parameters D04 & D05 over the command set. The limits are independent of each other and can be used stand-alone. The whole FFT can also be divided into two speed ranges with the parameter D06.
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FFT filter The FFT filter feature can be used to filter out specific regions in the FFT spectrum. The FFT filter array (see parameters A20…A27) consists of up to 8 independent FFT filters. Further the ± width around these FFT filters can be specified with the parameter D08. For example: The commands $A20000A, $A210032 & $A220050 define 3 FFT filters at the bin positions 10, 50 & 80. The command $D0802 sets the ± width around the filters to 2.
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Adjust hold time and s ensitivity The K-LD2 uses arrays with a width of 10 elements to set the range of hold time and sensitivity (see parameters A00…A09 for hold time and parameters A10…A19 for sensitivity). The used index of the arrays is defined using the parameters D00 and D01 or by the analogue inputs, if these are enabled with the parameters S0B and S0C. In the factory settings these arrays are filled with default values that will work for the most applications.
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COMMAND SET DESCRIPTION Command Classes The command set is divided into different classes. Every class contains a set of parameters.
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Command List All values are in hexadecimal notation unless otherwise noted. Table 8: Class S 8-Bit system parameters Param. Default Min Max Name Description S04 02 01 0A Sampling rate Sampling rate = value*1280Hz S05 10 01 40 Start up learn Number of FFT blocks that are used to learn the noise threshold average at start up. Only valid after reset. 01: no average at start up, fastest start up time 40: best average at start up, slowest start up time Only valid after reset.
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Table 9: Class D 8-Bit detection parameters Param. Default D00 Min Max 00 09 01 Name Description Hold time Index value to select an element of the hold time array defined with the parameters A00 … A09. This value has no effect if the parameter use hold time potentiometer S0C is enabled. D01 07 00 09 Sensitivity Index value to select an element of the sensitivity array defined with the parameters A10…A19. This value has no effect if the parameter use sensitivity potentiometer S0D is enabled.
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Table 13: Class F 16-Bit flash read parameters Param. Default Min Max Name Description F00 – 0000 FFFF Get software version Returns the firmware version of the sensor as a 16-Bit hex value. F01 – 0000 FFFF Get type of device Returns the type of the device, that the firmware is running on. For example: @F000078 " 120 " Version 01.20 0001: K-LD2 Table 14: Class R 8-Bit real-time read parameters Param.
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Table 16: Class C variable length complex read parameters Param. Default Min Max Name Description C00 – – – Get detection string C01 – – – Get target string Length Returns the detection register, the detection speed and the detection magnitude as an ASCII string in decimal format. 14 bytes Example response: 001;076;067; Returns an ASCII target list string in decimal format. It returns the speed and magnitude of the dominant movement for the forward and backward plane of the spectrum.
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Table 17: Class T 8-Bit testing parameters Param. T00 Default 00 Min Max 00 01 Name Description Activate testing mode Activates the testing mode. 00: Testing mode disabled 01: Testing mode enabled This parameter is not stored. After a reset or restart it is reset to the value 00.
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I N T E G R AT O R S I N F O R M AT I O N Installation Instruction Mechanical enclosure It is possible to hide the sensor behind a so called radome (short for radar dome) to protect it from environmental influences or to simply integrate it in the case of the end product. A radar sensor can see trough different types of plastic and glass of any colour as long as it is not metallized. This allows for a very flexible design of the housing as long as the rules below are observed. –– Cover must not be metallic.
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United States (FCC) and Canada (ISED) This module has been granted modular approval for fixed and/or mobile applications. The modular approval allows the end user to integrate the module into a finished product without obtaining subsequent and separate FCC/ISED approvals for intentional radiation, provided no changes or modifications are made to the module circuitry. Changes or modifications could void the user’s authority to operate the equipment.
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Europe (CE-RED) This module is a Radio Equipment Directive assessed radio module that is CE complaint and have been manufactured and tested with the intention of being integrated into a final product. According to the RED every final product that includes a radio module is also a radio product which falls under the scope of the RED. This means that OEM and host manufacturers are ultimately responsible for the compliance of the host and the module.
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We reserve all rights in this document and its subject matter. The recipient herby acknowledges these rights and assures the use of document only for the purpose it was delivered. © RFbeam Microwa Dieses Dokument ist unser geistiges Eigentum. Es darf ohne unsere ausdrückliche Genehmigung weder kopiert, vervielfältigt oder verwertet, noch an Dritte weitergegeben werden. Zuwiderhandlung ist strafbar und wird strafrechtlich verfolgt.
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REVISION HISTORY 06/2017 – Revision A: Initial Version 09/2018 – Revision B: Changes to Figure 2: Antenna characteristic Changes to Figure 15: Ordering number structure Changes to Table 18: Available ordering numbers Added Table of Contents and changed the title format 02 / 2020 – Revision C: Changed Supply current to RMS and peak current Added relative humidity to the operating conditions Changed the frequency drift and typical output power Added ESD level information Added new chapter integrators informat