In this paper, a methodology for designing a distributed model for coplanar asymmetry transformer on gallium nitride (GaN) process is proposed, which can accurately characterize the transformer’s feature up to a millimeter-wave band. The paper analyses a transformer-based matching circuit and proposes a practical transformer design procedure. A two stage, transformer matching based X-band power amplifier (PA) is reported here. Using the proposed transformer model and correlated transformer design procedure can sharply reduce schematic design period and optimum process time. The PA chip is designed on a 0.25 µm GaN technology process and occupies a 1.515 mm2 area. At a 28 V supply, the gain and output power of the PA reaches 15 dB and 29 dBm respectively, and the wideband matching transformer reaches 47.6% bandwidth. To the best of our knowledge, the distributed model for coplanar asymmetry transformer and transformer-based X-band MMIC PA on GaN process in this work is the first case among the reported papers.
This paper presents a GaAs-based Ka-band low noise amplifier (LNA) with gain flatness enhancement. Active device optimization and inductive degeneration techniques were employed to obtain a low noise figure (NF) and good input/output return loss. In order to achieve a flat gain response over a wide bandwidth, the stagger tuning technique was utilized. The proposed LNA was implemented by 0.15 μm GaAs pHEMT process, and the chip area is only 1.5 × 0.9 mm2. Measurement results show that the presented LNA exhibits a small signal gain of 21.5 ± 0.3 dB, and the NF of the LNA is less than 2.2 dB from 32 to 40 GHz at room temperature.
This work presents a transformer matching X band MMIC power amplifier(PA) on gallium nitride(GaN) process. A port impedance modeling-based transformer design method is proposed and analyzed. The method simplifies the transformer matching network design process, improves matching impedance accuracy, and relieves designer's burden. A novel compact temperature compensation (TC) circuit is also used in this design. The PA design on the 0.25µm MMIC GaN technology process, and occupies 1.594mm 2 area. At a 28V supply, the gain and output power of PA reaches 15dB and 29dBm respectively. Additionally, the designed TC circuit stabilizes PA current consumption from temperature variation. From -55 to 85℃, the PA current consumption stability improves by more than 60% by using the proposed TC bias circuit.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.