Design and robustness improvement of high‐performance LNA using 0.15 μm GaN technology for X‐band applications

Abstract

In this paper, we present a highly robust GaN-based X-band low-noise amplifier (LNA) showing promising small-signal and noise performance as well as good linearity. The LNA is fabricated using in-house 0.15 μm AlGaN/GaN on a SiC HEMT process. Owing to the optimum choice of HEMT topologies and simultaneous matching technique, LNA achieves a noise figure better than 2 dB, output power at 1 dB gain compression higher than 19 dB, input and output reflection coefficients better than À9 and À11 dB, respectively. The small-signal gain of LNA is more than 19 dB for the whole band, and NF has a minimum of 1.74 dB at 10.2 GHz. LNA obtains an OIP3 up to 34.2 dBm and survives input power as high as 42 dBm. Survivability is investigated in terms of gain compression and forward gate current. Reverse recovery time (RRT), a crucial parameter for radar front-ends, is explored with respect to the RC time constant and trap phenomenon. The analysis shows that the significant contribution in RRT is due to traps while the RC time constant is in the nanoseconds range. Moreover, this study also addresses the requirement and choice of a DC gate feed resistor for the subsequent stages in a multi-stage design. The size of the designed LNA chip is 3 mm  1.2 mm only.

Unveiling Tmax Inside GaN HEMT Based X-Band Low-Noise Amplifier by Correlating Thermal Simulations and IR Thermographic Measurements

“…1 with a 4x50 µm transistor (HEMT1) at the first stage and a 4x75 µm transistor (HEMT2) at the second stage. The design and performance of this LNA have already been reported in one of our previous works [41]. This study focuses on the thermal profiling of the HEMTs integrated into the MMIC using 3D FEA thermal analysis and IR thermography.…”

Design ofGaN‐basedX‐band LNAsto achieve sub‐1.2 dBnoise figure

“…The device and MMIC's fabrication process is discussed in detail in the authors' earlier works. 34,35,36 Small-signal and noise characterization for HEMTs and MMICs are performed using PNA-X from Keysight Technologies, Inc. (Santa Rosa, CA 95403, USA), ZVA40 from Rohde & Schwarz (München, Germany), and RF and DC probes from GGB industries Inc. (Naples, FL 34104, USA). AMCAD Engineering's (Limoges 87 068, France) IVCAD software, Maury's (Maury Microwave Technologies, Ontario, CA 91764, USA) tuners, and FormFactor's (FormFactor Inc., Livermore, CA 94551, USA) probe station are additionally used for large-signal characterization.…”

“…37 The significance of the R GB in terms of survivability is discussed in one of the authors' earlier works. 34 Figure 8A shows the stability parameters of CS HEMT without any stabilization network. Referring to Figure 5B, CS HEMT at the second stage is stabilized using a resistive network, Rs 1 , and Rs 2 , toward the gate side, along with bias capacitors and part of the matching networks containing Logb, Cobg, Lbd, Cobd, and Lo1.…”

“…Active and passive devices are fabricated using NANOTAM's 0.15 μm GaN‐on‐SiC technology. The device and MMIC's fabrication process is discussed in detail in the authors' earlier works 34,35,36 . Small‐signal and noise characterization for HEMTs and MMICs are performed using PNA‐X from Keysight Technologies, Inc. (Santa Rosa, CA 95403, USA), ZVA40 from Rohde & Schwarz (München, Germany), and RF and DC probes from GGB industries Inc. (Naples, FL 34104, USA).…”

“…R GB is a high value (1 kΩ in this design) first‐stage gate bias resistor used to enhance the survivability and does not affect the RF performance 37 . The significance of the R GB in terms of survivability is discussed in one of the authors' earlier works 34 …”