AN1229

SD2932 typical performances and conclusion

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SD2932 typical performances and conclusion

Figure 3, Figure 4 and Figure 5 show power gain, efficiency and input return loss over the

frequency range 88 - 108 MHz at a constant output power of 300 W and a drain supply

voltage of 50 V and a quiescent current of 200 mA. Typical performances are as follows:

Finally, in this report we have demonstrated ST’s SD2932 MOSFET transistor excellent

performance as a wideband 300 W - 50 V push-pull amplifier for FM applications.

Figure 6.

88-108 MHz circuit schematic

Table 2.

Typical performances

Parameters

Min

Max

Gp

19.3 dB

19.6 dB

-18 dB

-11 dB

Eff

71%

73%

Table 3.

88-108 MHz circuit components list

Symbol

Description

PCB

1/32” Woven fiberglass 0.0030 Cu, 2 side, er

T1

50

Ω Flexible coax cable OD 0.006”, 5” long

T2/ T3

9:1 Transformer, 25

Ω flexible coax cable OD 0.1” 3.9”. ferrite core NEOSIDE

T4 / T5

4:1 Transformer, 25

Ω flexible coax cable OD 0.1” 5.0” long.

T6

50

Ω flexible coax cable OD 0.1” 5.0” long.

FB1

VK200

C1

10 pf Ceramic capacitor

C2/C3/C4/C7/C8

1 nF Chip capacitor

C5/C6

1 nF ATC chip capacitor