Antennas for Wireless M2M Applications

6

Product Specification AE020157-O

Rufa 2.4 GHz SMD Antenna

Part No. A5839 / A5887

10 Electrical interface

10-1 Transmission lines

•

All transmission lines should be designed to have a characteristic impedance of 50 Ω

•

The length of the transmission lines should be kept to a minimum

•

Any other parts of the RF system like transceivers, power amplifiers, etc, should also be

designed to have an impedance of 50 Ω

Once the material for the PCB has been chosen (PCB thickness and dielectric constant), a

coplanar transmission line can easily be designed using any of the commercial software

packages for transmission line design. For the chosen PCB thickness, copper thickness and

substrate dielectric constant, the program will calculate the appropriate transmission line width

and gaps on either side of the track so the characteristic impedance of the coplanar

transmission line is 50 Ω .

10-2 Matching circuit

The antenna requires a matching circuit that must be optimized for each customer

’s product.

The matching circuit will require up to three components and the following pad layout should be

designed into the device so the correct circuit can be installed:

The antenna feed pad and the antenna ground pad are indicated in the drawing above.

Additional pads are for mechanical attachment only and should not be grounded.