MTT 2002Seattle June 5th

S. K. Leong

LDMOS and Vdmos

30 - 512 Mhz BroadBand Amps

30 - 512 Mhz Broadband AmpsA. 30 - 512 Multi-octave Military Amplifiers covering tactical ground, air, civil and those of allies.

B. Polyfet Technical Bulletins •Different Output Power and Gain•28V and 12.5V voltage supplies

C. 4:1 Broadband matching•Variable transformation ratio to match transistor Zin• Small physical size.

D. Computer Simulation results

Polyfet Technical Bulletins

Design Considerations• Load line required by device changes with frequency

• Load Pull techniques not practical for high power and low frequencies.

• Computer simulation using Spice model is preferred.

• 4:1 Most practical transformer for broadband

• Use effective inductance of coaxial transmission line as the inductive component in the PI matching network. Keep overall physical dimension small. (A lumped 4:1 replacing a 4:1 plus a low pass network)

Zin and Zout of Transistor

4:1 Transformer with Balun

4:1 TransformerFrequency ZIN[1] ZIN[1]

(GHz) Coax Transformer Coax Transformer (Real) (Imag)

0.03 11.10 4.920.08 12.94 1.910.13 13.07 0.940.18 12.99 0.450.23 12.87 0.170.28 12.73 0.020.33 12.60 -0.050.38 12.49 -0.060.43 12.41 -0.040.48 12.37 0.000.53 12.36 0.050.58 12.37 0.080.6 12.38 0.09

4:1 Transformer

0 1.0

1.0

-1.0

10.0

5.0

2.0

3.0

4.0

0.2

0.4

0.6

0.8

S11 4:1 TransformerSwp Max

0.6GHz

Swp Min

0.03GHz

0.2612 GHzr 0.255597x 0.00151298

S[1,1]Coax Transformer

4:1 with embedded lump matching

1 2

3 4

COAXI4

F=A=K=L=Z=

ID=

1 GHz0 2.3 3000 mil21 CX1

12

34

COAXI4

F=A=K=L=Z=

ID=

1 GHz0 2.3 3000 mil21 CX2

IND

L=ID=

500 nHL1

IND

L=ID=

500 nHL2

IND

L=ID=

500 nHL3

IND

L=ID=

500 nHL4

CAP

C=ID=

24 pFC1

CAP

C=ID=

3 pFC2

IND

L=ID=

2 nHL5

1

2

3

BALUN2

L=Mu=

F=A=

Er=Len=Zo=ID=

100 nH125 1 GHz0 dB2 2500 mil50 OhmBU1

CAP

C=ID=

1.1 pFC3

LOAD

Z=ID=

50 OhmZ1

PORT_PS1

PStep=PStop=PStart=

Z=P=

0 dB-30 dBm-30 dBm50 Ohm1

4:1 with embedded lump matchingFrequency ZIN[1] ZIN[1](GHz) Coax Transformer Coax Transformer

(Real) (Imag)0.03 11.91 4.130.08 12.17 -1.020.13 10.06 -2.170.18 8.35 -1.770.23 7.29 -0.790.28 6.75 0.340.33 6.64 1.420.38 6.83 2.330.43 7.21 2.950.48 7.62 3.220.53 7.86 3.200.58 7.80 3.050.6 7.69 2.99

• At low freq., matched to load line rather than impedance

4:1 with embedded lump matching

0 1.0

1.0

-1.0

10.0

5.0

2.0

3.0

4.0

0.2

0.4

0.6

0.8

S11 4:1 Matched to Transistor ZinSwp Max

0.6GHz

Swp Min

0.03GHz

0.261222869 GHzr 0.137995x -0.00171285

S[1,1]Coax Transformer

Picture of TB-160

Link to Application Note TB160

TB-160 Topview

TB-160 Sim. Schematic

CAP

C=ID=

1.1 pFC4

DCVS

V=ID=

2. 72 VVg

CAP

C=ID=

750 pFC2

1

2

3

CIRC

ISOL=LOSS=

R=ID=

100 dB0.001 dB50 OhmU3

DCVS

V=ID=

28 VVdd

I_METERID=Idrain

V_METERID=Drain Voltage

CAP

C=ID=

470 pFC1

CAP

C=ID=

470 pFC5

RES

R=ID=

9 OhmR2

RES

R=ID=

9 OhmR3

1 2

3 4

COAXI 4

F=A=K=L=Z=

ID=

1 GHz0 2 2500 mil17 CX4

12

34

COAXI 4

F=A=K=L=Z=

ID=

1 GHz0 2 2500 mil17 CX5

IND

L=ID=

1.012 nHL1

IND

L=ID=

1.012 nHL4

IND

L=ID=

1.5 nHL5

IND

L=ID=

1.5 nHL6

1

2

3

BALUN2

L=Mu=

F=A=Er=

Len=Zo=ID=

20 nH200 1 GHz0 dB2.1 2500 mil50 OhmBU1

1 2

3 4

COAXI 4

F=A=K=L=Z=

ID=

1 GHz0 2 3000 mil21 CX2

12

34

COAXI 4

F=A=K=L=Z=

ID=

1 GHz0 2 3000 mil21 CX6

CAP

C=ID=

1000 pFC3

CAP

C=ID=

1000 pFC6

CAP

C=ID=

3 pFC7

1

2

3

BALUN2

L=Mu=

F=A=Er=

Len=Zo=ID=

20 nH125 1 GHz0 dB1 2500 mil50 OhmBU2

IND

L=ID=

1000 nHL2 IND

L=ID=

1000 nHL7

IND

L=ID=

1000 nHL8

CAP

C=ID=

1000 pFC8

IND

L=ID=

1000 nHL3

RES

R=ID=

15 OhmR1

IND

L=ID=

15 nHL9

CAP

C=ID=

1e4 pFC9

CAP

C=ID=

1e4 pFC 10

IND

L=ID=

15 nHL10

RES

R=ID=

15 OhmR4

CAP

C=ID=

1e4 pFC 11

IND

L=ID=

15 nHL11 RES

R=ID=

100 OhmR5

CAP

C=ID=

1e4 pFC 12

IND

L=ID=

15 nHL12

RES

R=ID=

100 OhmR6

CAP

C=ID=

24.4 pFC 13

PRL

L=R=ID=

1000 nH22 OhmR L2

IND

L=ID=

1000 nHL13

IND

L=ID=

1000 nHL14

IND

L=ID=

1000 nHL15

IND

L=ID=

1000 nHL16

IND

L=ID=

500 nHL17

IND

L=ID=

500 nHL18

1 2

3

SUBCKT

N ET=ID=

"LX401MOD" S1

1 2

3

SUBCKT

N ET=ID=

"LX401MOD" S2

PORT1

P wr=Z=P=

38 dBm50 Ohm1

PORT

Z=P=

50 Ohm2

PORT

Z=P=

50 Ohm3

TB-160 30-512 Mhz Broad Band Amplifier

Link to AWR simulation file

MWO Simulation with layout

MWO Simulation. Pin =30dbm

Actual Measurement Pin=30dbmTB-160A LR401 Freq vs Gain/Efficiency; Vds=28Vdc Idq=1A

-15

-10

-5

0

5

10

15

0 50 100 150 200 250 300 350 400 450 500 550 600

Freq in MHz

-15

-10

-5

0

5

10

15

Return Loss

Gain

Pin fixed at 1W; 30 dBm

MWO Simulation. High Pin

Actual Measurement Pin=38dbmTB-160A LR401 Freq vs Gain/Efficiency; Vds=28Vdc Idq=1A

-15

-10

-5

0

5

10

15

0 50 100 150 200 250 300 350 400 450 500 550 600

Freq in MHz

10

20

30

40

50

60

70

80

90

100

Efficiency

Gain

Pin fixed at 6.3W; 38 dBm

Simulated Pin Pout at 250 Mhz

Measured Pin Pout at 250 MhzTB-160A Pin vs Pout Freq=250MHz Vds=28Vdc Idq=1A

30

35

40

45

50

55

20.00 22.00 24.00 26.00 28.00 30.00 32.00 34.00 36.00 38.00

Pin in dBm

10.5

11.0

11.5

12.0

12.5

13.0

13.5

14.0

14.5

15.0

15.5

16.0

Efficiency @60W= 40%

Pout

Gain

S11

TB160 ADS Small Signal Simulated

TB-160 ADS Pwr Simulated

Simulators

This circuit has been successfully simulated using•AWR Microwave Office 2002 Ver 5.5•Agilent ADS

Results are comparable between simulators

Conclusion

• Achieved multi octave broad banding with both Ldmos and Vdmos at high RF Output Levels

• Good correlation between Actual Measurements to Simulation using Polyfet Spice Models

•Small physical size matching network made possible by using inherent inductance of coaxial transmission lines along with shunt capacitance.

•Transistor impedance changes with frequency.