Robert J. Lender

Multi-Watt Wideband MMICs in GaN and GaAs

A comparison is presented of 4 to 18 GHz MMIC power amplifiers implemented in AlGaN-GaN HEMT and GaAs PHEMT with common circuit design technology. Both GaN and GaAs MMICs were designed as non-uniform distributed power amplifiers and achieved approximately 4 Watts over the band. The circuit complexity of the GaAs circuit is much greater than for GaN, as shown by the relative transistor output peripheries of 14.4 mm and 2 mm. The authors believe that both the GaN and GaAs MMICs have higher power than any published result of comparable bandwidth.

Micro-coaxial lines for active hybrid-monolithic circuits

This paper discusses fundamental properties of rectangular micro-coaxial lines fabricated in the PolyStrata™ process for broadband applications from 2–20 GHz. The possible impedance ranges for coaxial lines implemented with both five and eleven Cu layers are discussed and compared with measured results for the lowest impedance (8Ω) line. Power handling and thermal properties of these miniature lines are analyzed and measured. A 50Ω line with outer conductor cross-section of 600µm by 400µm is experimentally shown to handle 53W at 2:5GHz with a 10% duty cycle. Integration with active components is investigated and a 1–10GHz measurement of a GaN 50 MMIC amplifier shows minimal performance degradation relative to on-wafer measurements.

Wideband 1 to 6 GHz Ten and Twenty Watt Balanced GaN HEMT Power Amplifier MMICs

Design and performance of power amplifiers that have established benchmarks for 1 to 6 GHz power are reported. The 6 mm periphery balanced amplifier achieved a P3dB of 14.5 Watts max, 11.1 Watts average, 8.2 Watts min with 46.1 % max, 31.8 % average, 18.1 % min PAE and 9.6 dB max, 8.5 dB average, 7.5 dB min power gain from 1 to 6 GHz. The 8 mm periphery balanced amplifier achieved a P5dB of 26.7 Watts max, 20.6 Watts average, 13.9 Watts min with 44.4 % max, 30.8 % average, 17.8 % min PAE and 10.6 dB max, 10 dB average, 8.4 dB min power gain from 1 to 7 GHz. This output power, bandwidth, and efficiency is superior to the best previously reported results for both GaN HEMT and PHEMT power amplifiers [1, 2, 3].