Highly Linear Power Amplifiers for Broadband Wireless Applications

Highly Linear Power Amplifiers for Broadband Wireless Applications • Power Amplifiers for Wireless Communications Workshop • September 9, 2002 • M. Siddiqui, M. Quijije, A. Lawrence, B. Pitman, R. Katz, P. Tran, S. Din, L. Callejo, N. Yamamoto, K. Johnson, R Lai, R. Tsai and D. Streit

Applications Landscape ØHigher data rates dictate highly linear transmit chains ØMajor contributor to linearity and cost is the driver / power amplifier combination. 2

TRW Pseudomorphic HEMT Process • 0. 15 um T-gate process Source Drain Gate n+-Ga. As undoped Al. Ga. As • Breakdown > 8 Volts • f. T > 85 GHz at Vds > 4 volts • Gm > 500 m. S/mm • Imax > 500 m. A/mm Si plane doping undoped In. Ga. As undoped Al. Ga. As • 4 mil substrate thickness • Flight qualified, commercially proven process Ga. As substrate 3

TRW 0. 15 mm PHEMT Process Reliability • Ea » 1. 6 e. V, Sigma = 0. 6 • MTF » 6 X 1010 hours at Tj=125 o. C Ta=210 C Ta=235 C Ta=265 C Ta=250 C Typical benchmark, 1 X 106 hrs at 125 BC 4

Summary of Circuit Performance Part Name APH 478 30 GHz APH 496 APH 497 APH 502 APH 473 APH 474 Cell Freq 17 -20 29 -32 28 -31 32 -35 34 -36 37 -40 40 -44 Gain (d. B) 16 8 16 16 15 15 15 P 1 d. B (d. Bm) 30. 3 30. 2 26. 8 26. 5 30. 5 29. 5 Density @ 446 436 443 414 519 400 P 3 d. B (d. Bm) 31. 5 28 28 31. 5 31 31 Density @ 588 584 588 582 900 600 540 810 1080 5. 02 1. 86 2. 61 3. 55 4. 50 4. 25 (GHz) P 1 d. B (Mw/mm) P 3 d. B (Mw/mm) IDC @ 5 V (m. A) Die Size (mm 2) State of the art output power density enables smaller die size and less DC power dissipation 5

37 to 40 GHz Power Amplifier APH 473 Die Size = 4. 5 mm 2 Power Density @ P 1 d. B = 400 m. W/mm Power Density @ P 3 d. B = 582 m. W/mm 6

37 to 40 GHz Power Amplifier Performance vs. DC Bias 7

37 to 40 GHz Power Amplifier Performance vs. Temperature Gain Yield at 38. 5 GHz 8

40 to 44 GHz Power Amplifier APH 474 Die Size = 4. 25 mm 2 Power Density @ P 1 d. B = 400 m. W/mm Power Density @ P 3 d. B = 582 m. W/mm 9

17 to 20 GHz Power Amplifier APH 478 Die Size = 5. 02 mm 2 Power Density @ P 1 d. B = 446 m. W/mm Power Density @ P 3 d. B = 588 m. W/mm 10

28 to 31 GHz Driver Amplifier APH 496 Die Size = 2. 61 mm 2 Power Density @ P 1 d. B = 443 m. W/mm Power Density @ P 3 d. B = 584 m. W/mm 11

29 to 32 GHz Power Cell Die Size = 1. 86 mm 2 Power Density @ P 1 d. B = 436 m. W/mm Power Density @ P 3 d. B = 588 m. W/mm 12

32 to 35 GHz Driver Amplifier APH 497 Die Size = 2. 61 mm 2 Power Density @ P 1 d. B = 414 m. W/mm Power Density @ P 3 d. B = 584 m. W/mm 13

34 to 36 GHz Power Amplifier APH 502 Die Size = 3. 55 mm 2 Power Density @ P 1 d. B = 519 m. W/mm Power Density @ P 3 d. B = 588 m. W/mm 14

Conclusion • Higher data rates dictate a need for highly linear transmit chains. • A major contributor to linearity and cost is the driver / power amplifier combination. • Maximizing the output power density in the driver / power amplifier chain enables reduced die size and DC power consumption. • Velocium’s PA MMICs have shown state of the art linearity and power density in a production process. 15