Application Note

300 Watt Class E Amplifier Using MRF151A

Application Note

AN4001

Rev. 01262010

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is considering for development. Performance is based on target specifications, simulated results,

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Data Sheets contain information regarding a product M/A-COM Technology

Solutions has under development. Performance is based on engineering tests. Specifications are

typical. Mechanical outline has been fixed. Engineering samples and/or test data may be available.

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Table 1. Performance of Class E amplifier with MRF151A MOSFET

Figure 9. Performance of Class E amplifier with MRF151A MOSFET

Pout

(Watts)

Pout

(dBm)

Pin

(Watts)

Pin

(dBm)

Gain

(dB)

Id

(Amps)

Eff

(%)

Vd

(Volts)

H2

(dBc)

H3

(dBc)

300

54.8

24.3

43.9

10.92

7.61

82.1

48.0

-39

-57

250

54.0

9.5

39.8

14.19

6.67

78.1

-

-39

-56

200

53.0

6.1

37.9

15.15

5.75

72.5

-

-38

-57

150

51.8

4.3

36.3

15.43

4.74

65.9

-

-37

-59

100

50.0

3.1

34.9

15.07

3.75

55.6

-

-35

-57

50

47.0

1.9

32.7

14.29

2.47

42.2

-

-34

-56

5

37.0

0.6

27.8

9.21

0.71

14.6

-

-32

-46

PERFORMANCE OF CLASS E AMPLIFIER WITH MRF151A

0

50

100

150

200

250

300

350

0.0

5.0

10.0

15.0

20.0

25.0

30.0

Pin (watts)

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

Pout

Efficiency

At 300 watts, second and third harmonic levels are –39dBc and –57dBc respectively. If necessary the

harmonic levels can be improved further by including additional filter stages.

The drain voltage was also measured using an oscilloscope and it is shown in Figure 10. Although

the limited frequency response of the probe and EM interference are masking some of the higher

frequency components it can be seen that the simulated voltage waveform shown in Figure 4 is a

reasonable prediction of the measured waveform.