MITSUBISHI RF POWER MODULE

RA 08H1317 M

RA08H1317M

MITSUBISHI ELECTRIC

23 Dec 2002

8/9

ELECTROSTATIC SENSITIVE DEVICE

OBSERVE HANDLING PRECAUTIONS

Output Power Control:

Depending on linearity, the following two methods are recommended to control the output power:

a) Non-linear FM modulation:

When the gate voltage is close to zero, the RF input signal is attenuated up to 60 dB and only a small leakage

current flows from the battery into the drain.

b) Linear AM modulation:

The gate voltage is used to set the drain’s quiescent current for the required linearity.

Oscillation:

To test RF characteristics, this module is put on a fixture with two bias decoupling capacitors each on gate and drain,

a 4.700 pF chip capacitor, located close to the module, and a 22 µF (or more) electrolytic capacitor.

When an amplifier circuit around this module shows oscillation, the following may be checked:

a) Do the bias decoupling capacitors have a low inductance pass to the case of the module?

Ω?

Ω?

Frequent on/off switching:

In base stations, frequent on/off switching can cause thermal expansion of the resin that coats the transistor chips and

can result in reduced or no output power. The bond wires in the resin will break after long-term thermally induced

mechanical stress.

Quality:

Mitsubishi Electric is not liable for failures resulting from base station operation time or operating conditions exceeding

those of mobile radios.

This module technology results from more than 20 years of experience, field proven in tens of millions of mobile radios.

Currently, most returned modules show failures such as ESD, substrate crack, and transistor burnout, which are

caused by improper handling or exceeding recommended operating conditions. Few degradation failures are found.

Mitsubishi Electric Corporation puts the maximum effort into making semiconductor products better and more reliable, but

there is always the pos sibility that trouble may occur. Trouble with semiconductors may lead to personal injury, fire or property

damage. Remember to give due consideration to safety when making your circuit designs, with appropriate measures such

as (i) placement of substitutive, auxiliary circuits, (ii) use of non-flammable material, or (iii) prevention against any

malfunction or mishap.

Keep safety first in your circuit designs!