User's Manual

ManualsBrandsST Electronics ManualsElectronicsK-Band Miniature FMCW RF Transceiver Module

1 of 16

MSAN

008

K-Band FMCW Transceiver DF Modules

Application Note

V1.0

ST Electronic

s (Satcom & Sensor Systems) Pte Ltd

1 Ang Mo Kio Electronics Park Road, #06-02, ST Engineering Hub, Singapore 567710

Tel: (65) 6521 7888 Fax: (65) 6521 7801 Email: info@agilsense.com

Website: www.agilsense.com ( Regn. No.: 199103901W )

1. Introduction

2. User interface and mounting

6-way 2.54 mm pin header is used for user interface and the four mounting holes of M2.5 screw size are

as shown in Figure 2

Figure 1: Block Diagram

The DF9 series (Frequency Modulated Continuous Wave)

microwave motion sensor modules are K-Band Bi-static

FMCW transceiver front-end modules. These modules are

designed for distance measurement, speed detection

together with direction of motion recognition. It is suitable

for intrusion detection and various traffic applications.

The module consists of Voltage controlled Oscillator

(VCO), balanced mixers; patch antenna, built-in LNA for

high sensitivity and a pre-amplifier (see Figure 1).

This Application Note highlights some important points for

application with DF9 series.

Pin definition

1: EN (Oscillator Enable)

2: V

(Input Voltage)

3: GROUND (Ground)

4: I (IF Output)

5: Q (IF Output)

6: V

(Tuning Voltage)

Figure 2: Pin definition and mounting holes

Mounting

through holes

size M2.5.

Summary of content (16 pages)

PAGE 1
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 1. Introduction The DF9 series (Frequency Modulated Continuous Wave) microwave motion sensor modules are K-Band Bi-static FMCW transceiver front-end modules. These modules are designed for distance measurement, speed detection together with direction of motion recognition. It is suitable for intrusion detection and various traffic applications.
PAGE 2
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 3. Power Supply For supply voltage, there is a built-in voltage regulation in the DF series transceivers. As such, the performance of the DF9 seriesis not affected by variation of supply voltage as long as it is within the specification. For example, performance of DF9 series will not be affected for any supply voltage from 3.6V to 9V. In this case, DF9 series is capable of being powered by standard voltage of 5V. 4.
PAGE 3
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 Frequency Vs Tuning Voltage Frequency Unit 1 Unit 2 Unit 3 6 8 Unit 4 24.4 24.35 24.3 24.25 24.2 24.15 24.1 24.05 24 23.95 0 2 4 10 12 14 Tuning Voltage Figure 3: FMCW Tuning Slope Calibration is highly recommended for every unit. 5.
PAGE 4
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 Stationary Object For stationary object, simple sawtooth shape frequency sweeping is suggested as there is no requirements for measuring velocity. By varying tunning voltage , user will be able to obtain plot of frequency versus time. Transmitted signal Received signal Figure 4: Detection of Stationary Object The solid line indicates transmitting signal while the dashed line indicates received signal from object.
PAGE 5
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 Moving Object For detection of moving object, the triangle wave is suggested in order to obtain information on distance and velocity ( Figure 5). Transmitted signal fd fif- Received signal fif+ Transition Period Figure 5: Detection of Moving Object The solid line in figure 5(a) indicates transmitted signal while the dashed line indicates reflected signal.
PAGE 6
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 So, object’s distance R can be calculated based on this formula: c  fR 2k R Where fR  f if   f if  2 Object’s velocity v is given by: v fd  c 2  f0 Where f 0 is the frequency of transmitted signal and fd  f if   f if  2 Please refer to Annex 2 for more detailed FMCW moving object range and velocity calculation.
PAGE 7
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 6. Radiation Pattern The module to be mounted with the antenna patches facing to the desired detection zone. The user may vary the orientation of the module to get the best coverage. The radiation patterns of the antenna and their 3dB beam width are shown in below diagram.
PAGE 8
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 7. IF amplifier gain and frequency response The DF9 series transceiver module comes with a built-in two-stage IF amplifier. The amplifier is designed to provide low noise and hence, higher sensitivity. Besides, this amplifier acts as a buffer so that the performance of the DF module is not affected by the loading at the IF output. A loading of at least 1 k is recommended at the IF output.
PAGE 9
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 8. IF output signals This section shows a typical signal at output from DF990 when pointed to the wall at certain distance. This section means to serve as a guide. Tuning Voltage Frequency: 10 KHz Tuning Voltage Range; 1-6V Sweeping Type; Triangle Function. Figure 8 shows the signal at IF output when there is no target in the detection range of sensor.
PAGE 10
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 Figure 9: IF Output Signal and Input Tuning Voltage with target detected. Figure 10 to 13 show the signals from IF output when targets at different distance are detected. Figure 10: I and Q signal when no target detected ST Electronics (Satcom & Sensor Systems) Pte Ltd 1 Ang Mo Kio Electronics Park Road, #06-02, ST Engineering Hub, Singapore 567710 Tel: (65) 6521 7888 Fax: (65) 6521 7801 Email: info@agilsense.com Website: www.
PAGE 11
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 Figure 11: I and Q signal with target detected at 1m away Figure 12: I and Q signal with target detected at 3m away ST Electronics (Satcom & Sensor Systems) Pte Ltd 1 Ang Mo Kio Electronics Park Road, #06-02, ST Engineering Hub, Singapore 567710 Tel: (65) 6521 7888 Fax: (65) 6521 7801 Email: info@agilsense.com Website: www.agilsense.com ( Regn. No.
PAGE 12
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 Figure 13: I and Q signal with target detected at 5m away There are two output signals in DF9 series: I and Q signal. As the figures shown, amplitude of output signal becomes smaller when distance increases, while the frequency of output signal increases with distance. When the distance of detected object is small enough, frequency difference of transmitted and received signal will be equal or even less than sweeping frequency.
PAGE 13
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 It is recommended that the cover placed in front of the DF antenna is of flat panel, so that the beam width of the antenna is not significantly distorted. The thickness of the cover, h1 and the spacing between the antenna and the cover, h2 should be ideally half-wavelength of the microwave signal. In this case, for DF series module whose transmission frequency is ~24GHz, the recommended h1 and h2 are 3-4mm and 6mm.
PAGE 14
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 12. Radiation Safety Microwave radiation from the module is well below established safety standards for general public environment, like ANSI C95.1-1991 of USA and NRPB-G11 of United Kingdom. 13. Handling The module has been fully tested to specifications. Opening, tightening or loosening the chassis may result in performance deterioration. The module is an electrostatic sensitive device (ESD).
PAGE 15
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 Annex 1: Transmission of RF 1. Though same frequency is allocated in some countries, national regulations may specify different EIRP, spurious emission or other requirements. The DF990 model is designed to meet the FCC standard part 15.245 and is aimed for use in the America. The regulations are subjected to change from time to time, please contact appropriate authorities for full and up-to-dated information. Useful websites: 2. 3. 4.
PAGE 16
MSAN-008 K-Band FMCW Transceiver DF Modules Application Note V1.01 Moving Object Due to the existence of doppler frequnency in the f if  and f if  , the frequency associated to range is given by: fR  f if   f if  2 Hence, object’s distance is given by: Where R c  fR 2k k  B T T: frequency sweeping period of sensor B : frequency sweeping bandwidth.