DS0353-9 March ‘05

©2005 Reg. No. 227 4001, ENGLAND

Page 11

TRXQ1

RXQ1

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).

Contents

•

Two Eval Boards

•

Two RF600T Comms Controllers

•

Circuit diagrams

Two RS232 PC cables

Radio Modules and Antenna available

Separately.