10 GHz high power amplifiers

EME Conference Orebro 2015

Goran Popovic AD6IW

Available technologies

• TWT

• GaN transistors

• GaAs transistors

• Very efficient, bulky,

high voltage, x-ray

• High power density,

gain, very expensive

• Low voltage and

efficiency devices,

surplus available

GaN Transistors

• Triquint TGA2312 9-

10GHz, 48dBm 13dB

38% eff.

• Cree CMPA601C025F

6-12GHz 46.2dBm 33dB

28V 33% eff.

Sumitomo elect. SGK1011-

2A, 10dB, 33% eff.

Toshiba TGI0910-50. 31%

9dB

GaAs FET’s

• Fujitsu, Eudyna,

Sumitomo Electric

FLM0910, FLM1011

series, 3-25W 10V

• Toshiba TIM0910,

TIM1011 series

Surplus

• Alcatel

• Three stages x band amplifier

• Fujitsu FLM1011

• 3W, 8W, 12W GaAs Fet’s. In some units 15W final device

• Can be used as driver for high power amp.

Amplifier line ups

RF IN 23-25 dBm

7.5 dB 3W 7.5dB 8W

6dB 12W

7.5dB 15W

Driver amplifier

RF OUT

RF IN

RF OUT

90 deg. 3dB splitter 90 deg. 3dB combiner

7.5dB 8W

6dB 12W

7.5dB 15W

7dB 25W

3dB higher Power and

Linearity

Balanced configuration

amplifier, two amp’s

RF IN

RF OUT

7.5dB 8W

6dB 12W

7.5dB 15W

7dB 25W

6dB higher Power and

Linearity

Driver amplifier design and

simulations

Final amplifiers

50W Balanced amplifier

• 2 x FLM0910_25F

• 8dB gain

• Idq 12.8A at 10V

GaAs fet’s bias circuits

DC

Rg

Rint.

I>0

No forward current

DC

Rg

Igs

I>0

Rp

Rp< =-Vpmax/2Igsmax

For FLM0910-25F

Rp=25Ohms

Rp power dissipation (2x)

Rp=Vpmin.sqr/Rp

Forward Gate current

64mA, Reverse Gate

current -11.2mA

Approx. Rp = 400 / Psat

Rp diss = -0.5V sqr / 25

10mW use 1/4W res.

DC

Rg

DC

Rail to Rail Op amp

Totem pole configuration,

Very low output

impedance, drive

capacitive loads, and

provide GaAs FET with

forward and reverse Gate

currents

DC

470 Ohms

330 Ohms500 Ohms

-5V from ICL7660

10mA with 0.5V output

drop !

TIM0910-8

Forward Gate current

32mA

Reverse Gate current

-4.1mA

Suggested Rg 100 Ohms

200 Ohms @ -2.94V

300 Ohms @ -1.8VTypically, Tc of Pot is 200-

300ppm Variation of gate

voltage is 100-150mV over

temperature changeCommon bias circuits

published in ham radio

magazines

Issue

Low drive level the gate

current Igs is negative and

constant, but with high

level drive Igs is possitive

and can be large up to

hundreds of mA !

Control board schematics

• Four bias voltages

• 50mS sequencing

• 3W DC/DC converter

• Isolated switch

• T/R control

Implemenation and results

• 23dB gain

• 23dBm in 46.5dBm

45W Out

• PAE > 20%

• 13.5V 18A

• Unconditional stable

• Switching high side

mosfet Rds_on issue

Testing

Future developments

• Balanced amplifier with pair of

CMPA601C025 Cree GaN MMIC

• 25W each, 28V > 30dB Gain

• Multi ports power splitter-combiner

Wave guide Combiner

Questions ?

• Thank You

• Goran@ad6iw.com