MC68HC908RF2 Datasheet, PDF (244/254 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Preliminary Electrical Specifications
17.9.2 UHF Module Output Power Measurement
The RF output levels given in the 17.9.1 UHF Module Electrical
Characteristics are measured whith a 50-Ω load directly connected to
the pin RFOUT as shown in figure Figure 17-4. This wideband coupling
method gives results independant of the application.
V_CC
RFOUT
IMPEDER: TDK MMZ1608Y102CTA00
RF OUTPUT
100 pF
50 Ω
Figure 17-4. Output Power Measurement Configurations
The configuration shown in Figure 17-5(a) provides a better efficiency
in terms of output power and harmonics rejection. Schematic in
Figure 17-5(b) gives the equivalent circuit of the pin RFOUT and
impeder as well as the matching network components for 434-MHz
frequency band.
NOTE: Note that the impeder is moved to the load side to decrease its influence
(similar to dc bias through the antenna).
Figure 17-6 gives the output power versus the R_EXT resistor value, in
both cases with 50-Ω load and with matching network.
Advance Information
244
Preliminary Electrical Specifications
MC68HC908RF2 — Rev. 1
MOTOROLA