User's Guide
Table Of Contents
FUJITSU COMPONENT LIMITED
8
Calculation example
IF band width: B
Converted speed
Noise level: V
if_noise
1Hz - 1kHz
0.022 - 22km/h
0.6 uVrms
1Hz - 10kHz
0.022 - 223km/h
1.8 uVrms
1Hz - 100kHz
0.022 - 2234km/h
5.6 uVrms
It is recommended to use the amplifier with the noise as low as possible since the noise of
the external amplifier connected to IF1/2(I/Q) terminals is added.
Relation between IF signal frequency and object speed
The faster Object moves, the bigger the frequency difference between Tx and Rx. Then,
higher the IF frequency. The relation between IF signal frequency and object speed is shown
by the formula (5) below.
[m/s] ……………………… (5)
IF frequency ：
RF(carrier) frequency ：
Speed of light ：
The table below is the calculation example of the formula (5).
Calculation example
IF frequency
Calculated speed
Remarks
45Hz
1km/h
Swimming speed
224Hz
5km/h
Walking speed
540Hz
12km/h
Bicycle speed
2240Hz
50km/h
Car speed
4480Hz
100km/h
Car speed on high way
Relation between IF signal phase and moving object
6-1. Output signal waveform of IF(I-signal) and IF(Q-signal)
This module outputs I-signal and Q-signal those phase different by 90 degrees as IF signal
by the orthogonal modulation/demodulation circuitry consisting of mixer, VCO, and phase
shifter.
The frequencies corresponding to the object speed. The wave forms between I-signal and q-signal are
almost same each other.
(Tx radio frequency) < (Rx radio frequency)
→ Q lead I by 90 degrees
Q
I