DS0353-9 March ‘05 ©2005 Reg. No. 227 4001, ENGLAND Page 11
TRXQ1
RXQ1
FM N
ARROW BAND TRANSCEIVERS
Antenna Design
The design and positioning of the aerial is as crucial as the module performance itself in achieving a good
wireless system range. The following will assist the designer in maximising system performance.
The RF ground pin should be connected to a ground plane which should shield the aerial connection and the
PCB layout around the aerial track itself should be such as to give a 50 Ohm impedance. The aerial should be
kept as far away from sources of electrical interference as physically possible. The specified power supply
decoupling capacitors should be placed close to the module as possible and have direct connections to the
relevant pins.
The antenna ‘hot end’ should be kept clear of any objects, especially any metal as this can severely restrict the
efficiency of the antenna to receive power. Earth planes restricting the radiation path of the antenna will also
have the same effect.
The best range will be achieved with either a straight piece of wire, rod or PCB track @ ¼ wavelength (15.5cm
@ 433.92MHz). Increased range may be achieved if this ¼ wave antenna is placed perpendicular to and in
the middle of a solid earth plane measuring at least 16cm radius. In this case, the antenna should be
connected to the module using 50 Ohm coaxial cable and the PCB track layout tips given above should be
observed.
RF
RF
Helical Antenna Whip Antenna
34mm @ 433MHz
17 turns equally spaced
∅
= 5mm (inside)
15.5cm @ 433MHz
Smart Radio Evaluation Kit (Please see Datasheet DS605)
The Smart Radio Evaluation Kit provides a hardware platform to enable
fast development of Radio applications.
Supplied as a pair of boards, each can accept a variety of RF Modules
including transmitters, receivers and transceivers, an RS232 port is
incorporated for direct connection to a PC.
The boards may be used for a wide range of tasks from simple RS232
data transmission to integrated system development and is the ideal
platform for exploring the advantages of using the “Smart Comms” range
of ICs and radio modules.
This eliminates the need to construct hand-wired prototype boards, which
are rarely successful in creating a valid environment for the development
of radio systems. (prototyping board also contains large stray capacitance
values which has a detrimental effect on the RF connections).
•
Hardware Platform for Radio Comms Development
•
Accepts Various RF Modules
•
RS232 Interface to PC
• Supplied with RF600T Smart Comms Controller
•
Performs all Data Encryption for Reliable Data Comms.
•
Two Telemetry I/O Lines (addressed mode only)
•
Range Testing
•
Target Environment Testing
•
Antenna Evaluation
Contents
•
Two Eval Boards
•
Two RF600T Comms Controllers
•
Circuit diagrams
•
•
Two RS232 PC cables
Radio Modules and Antenna available
Separately.
