User's Guide
Table Of Contents
FUJITSU COMPONENT LIMITED
4
Tx antenna, power feed point
Rx antenna, power feed point
Signal gain
3-1. Gain between power feed point of Tx and Rx (Propagation Loss)
This Doppler Radar Sensor receive the radio wave, which the Doppler Radar Sensor
transmitted, reflected from object.
The attenuation at the reflection depends on the cross section and material of the object.
Fig.2 Reflection and propagation conditions
In case the object consists of metal, the signal level between Tx antenna power feed point
and Rx antenna power feed point is generally calculated by the formula (1) below.
………………………… (1)
Physical Constants
Light speed ：
RF(carrier) ：
Wave length ：
FWM7RAZ01 eigenvalues
PA Tx power ：
[W]
Tx antenna gain ：
Note) Gain is max value.
Application dependent parameters
Distance to object ：
Rainfall attenuation ：
Radar Cross Section (RCS) ：
(Caution) This RCS is not equal to a cutting cross section
The measure of a target's ability to reflect radar signals in the
direction of the radar receiver.
Samples of RCS (σ) 0.01m
2
= Crow
0.5m
2
= Adult man, Coke can
1～5m
2
= Car
A few hundred m
2
= 1m
2
Metal plate
（Please note that it varies depending on the shape and material of the object.）
PA
LNA
Tx-Power
Pt
Rx-Power
Pr
Antenna Gain
Gtx
Grx
Antenna Gain
Wave length
Rainfall attenuation
Ls
Distance
R
Moving Object
Radar
Cross
Section
σ