DS620-3 Jan ‘07

©2007 Reg. No. 227 4001, ENGLAND

Page 7

RF620T

RF620R

SmartRadio Transmitter / Receiver

Mechanical Details

Component Side

13

63.5

14.5

2.54

713

15

Notes

Dims in mm

Pins on 0.1" pitch

Pin Dims :0.25 x 0.50 mm

3

1.27

20

25

11

RF620R

Component Side

25.5

11.5

2.54

9

3

5

RF620T

1

1.27

10

Antenna Design

The design and positioning of the antenna 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 (17.3cm

@ 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 Solutions Ltd.,

Unit 21, Cliffe Industrial Estate,

South Street, Lewes,

E Sussex, BN8 6JL, England

Tel +44 (0)1273 898 000

Fax +44 (0)1273 480 661

Email sales@rfsolutions.co.uk

http://www.rfsolutions.co.uk

All Trademarks acknowledged and remain the property of the respected owners

Information contained in this document is believed to be accurate, however no representation or warranty is given and R.F. Solutions Ltd. assumes no liability with respect to the accuracy of such

information. Use of R.F.Solutions as critical components in life support systems is not authorised except with express written approval from R.F.Solutions Ltd.