ATSAM4S-WPIR-RD Atmel, ATSAM4S-WPIR-RD Datasheet - Page 27

• Manufacturer Part Number: ATSAM4S-WPIR-RD
• Description: Development Boards & Kits - ARM SAM4S16 W.PIR CAMERA REF. DESIGN
• Manufacturer: Atmel

Specifications of ATSAM4S-WPIR-RD

• Rohs: yes
• Product: Reference Designs
• Tool Is For Evaluation Of: ATSAM3S4BA
• Core: ARM Cortex M3
• Interface Type: JTAG, USB
• Operating Supply Voltage: 5 V
• Data Bus Width: 32 bit
• For Use With: RF231USB-RD

5.5
According to a calculation with the ‘Flat Earth Model’ in respect to the given values a maximum distance of about 213
meters should be reachable. The Flat Earth Model describes a flat, electrical conducting plane on which two radio
devices are placed, located in the height h and the distance d for which applies d >> h. The propagated wave will be
received directly and indirectly, respective mirrored on the flat plane. The path loss is higher (fourth power) than within a
theoretical free space environment (square power).
Parameters:
Flat Earth Model
Rearranged to
The measured range in the real environment is about 230 meters. That means that calculation and measurement is
nearly comparable. Differences may result of position and radiation patterns of the antenna and USB dongle plugged
into laptop.
Notes:
PCB detail 6 – coaxial connector
The PCB has a footprint for an U.FL coaxial connector X3 (U.FL-R-SMT-1 by Hirose). This connector was used only for
test measurements. The footprint is designed according to manufacturer’s datasheet [6]. The resistor R2 near the
feeding pad of X3 protects the RF transceiver against electrostatic discharges of coaxial plugged devices or human
contacts. The default assembled capacitor C40 enables the antenna feed. For a coaxial connection, capacitor C40 has
to be disassembled and C33 mounted. Both capacitors have a value of 22pF.
Figure 5-13. Board layout – coaxial connector.
Height transmitter
Height receiver
Transmit power
Receive power
Transmitter antenna gain
Receiver antenna gain
Sensitivity
Distance
Path loss
1.
2.
3.
10
213.24
According to [5].
Measured at 250kbit/sec.
According to [7].
(3)
and setting
(2)
20
Atmel AVR2030: ATRF231USB – Hardware User Manual [APPLICATION NOTE]
(1)
20
:
1.40
1.40
3.0
0.5
0.5
40
97.0
42018A−AVR−08/2012
27