Larry C. Witkowski

Low-noise, low DC power linear amplifiers

Low-noise, low-DC-power linear amplifiers using high-dynamic-range GaAs/int FETs are discussed. Noise figures as low as dB have been achieved in a Ku-band amplifier simultaneously with over 36-dBm OIP3 and 18-dB gain with only 655 mW of DC power. A wideband distributed amplifier has shown average midband 7-dB gain and noise figure together with 37-dBm OIP3 with 800 mW of DC power. Greatly improved second-order intercept points (OIP2) have been observed in the distributed amplifier as compared to typical ion-implanted MESFET amplifiers. A dual-gate version, of the distributed amplifier demonstrated significant dynamic range advantages over its ion-implanted FET counterpart. Overall, state-of-the-art results in terms of simultaneous linearity, noise figure, gain-bandwidth, and DC power consumption have been achieved.<<ETX>>

Embedded transmission-Line (ETL) MMIC for low-cost high-density wireless communication applications

A new embedded transmission-line (ETL) monolithic-microwave integrated-circuit (MMIC) approach which allows flexibility in mixing different transmission-line types (i.e., coplanar and striplines) for maximum MMIC design flexibility and permits the feasibility of eliminating backside processing for low production cost is described. This ETL MMIC approach is an enabling technology allowing for low-cost batch fabrication, and high-density integration of microwave and RF components (including silicon mixed-signal products) for emerging wireless communication applications. Designs and performance results of a number of ETL MMICs are described in this paper.

Low-Noise, Low DC Power Linear FET

A two-tone third-order output intercept point (OIP3) of 45 dBm has been achieved at 10 GHz with a 280-¿m GaAs MBE FET using only 248 mW of DC bias giving an OIP3/Pdc ratio of 128. Noise figure at that bias and tuning was 3.23 dB. Minimum noise figure of the same device was 1.43 dB.

K/Ka-band low-noise embedded transmission line (ETL) MMIC amplifiers

The design, fabrication, and performance of producible, high-performance K-, and Ka-band pHEMT low-noise MMIC amplifiers using the embedded transmission line (ETL) circuit concept with top-side grounding are reported. A state-of-the-art noise figure of 1.2 dB with 25 dB gain is achieved at 31 GHz. These amplifiers can be implemented in low-cost, ultra compact receiver modules for emerging spaceborne phased-array communication applications.