NJR4274
＊Above specifications are subject to change without notice.
Reference No.:
PDS-R4274
Rev.:
00-06E
Sheet:
2
Scope
NJR4274 K-band (24GHz) Doppler Module has been designed for motion sensing applications.
Main Structure
Integrated antenna structure, the patch antenna is integrated on the module PCB.
All of electric parts except interface connector are covered with metal cap.
Operation Overview
5 V input operation, LDO integrated.
Implemented an internal MCU for RF frequency tuning of RF-IC and intermittent-operation.
Internal MCU controls ON/OFF of Output voltage from LDO which connect to the input voltage
terminal of RF IC.
This module is 2-frequencies CW (FSK) type sensor that can simultaneously measure the distance
and velocity of the moving target. It operates duty cycle of intermittent-operation has 2-operation-
mode (Normal operation mode / Low power operation mode). 2-operation-mode are different duty
cycle. (refer Fig.2)
RF frequency is output during ON time.
Internal MCU supplies the tuning voltage to RFIC and the RF frequency is controlled by tuning voltage.
Since the RF frequency is switched every intermittent-operation cycle, the tuning voltage is switched
every cycle.
Switched RF frequency is 2-frequencies, and difference of those 2-frequencies is 15 MHz +/- 3 MHz.
Fig.1 Functional Block Diagram