Browsing by Subject "LNA"
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Item Open Access Broadband GaN LNA MMIC development with the micro/nano process development by kink-effect in S22 consideration(Bilkent University, 2021-01) Osmanoğlu, SinanBroadband low noise amplifiers (LNA) are one of the key components of the nu-merous applications such as communication, electronic warfare, and radar. The requirements for higher bandwidth, higher speed, higher survivability, higher re-liability, etc. pushes the technological boundaries. The demand for high per-formance circuit components without a compromise stimulates the utilization of the high-end gallium nitride (GaN) technology to develop better monolithic microwave integrated circuits (MMIC) in a smaller footprint. To support the progress, the development of a proper GaN high electron mobility transistor (HEMT) technology and proper circuit models have become critical. To support the efforts and contribute to the progress, a 0.25 µm microstrip (MS) GaN HEMT technology is developed in Bilkent University Nanotechnology Research Center (NANOTAM). The technology development yields that the MS GaN HEMT tech-nology is capable of supporting ≥4.4 W/mm output power (POUT ), ≥50% power added efficiency (PAE), ≥15 dB gain, and ∼1 dB noise figure (NF ) at 10 GHz. Moreover, the gate structure of the technology is studied by evaluating the kink-effect (KE) in the output reflection coefficient (S22) of a HEMT to support the broadband operation. Besides the technology development, the small-signal (SS) and noise equivalent circuit models are studied, and the developed models present high convergence with the measurements. The accuracy of the models contributes to development of the cascode HEMT based LNAs even without fabricating the cascode HEMT. Furthermore, the developed models and the proper gate struc-ture are used to develop the broadband quad-flat no-leads (QFN) packaged GaN LNA MMIC for the mobile radio communications, the military radar, and the commercial radar applications. The results of the circuit models and the GaN LNA MMIC also yield that the developed MS GaN HEMT technology is capable for developing different solutions up to 18 GHz.Item Open Access From model to low noise amplifier monolithic microwave integrated circuit: 0.03–2.6 GHz plastic quad-flat no-leads packaged Gallium-Nitride low noise amplifier monolithic microwave integrated circuit(John Wiley & Sons Ltd., 2021-01-19) Osmanoğlu, Sinan; Özbay, EkmelThis paper describes an air cavity quad-flat no-leads (QFN) over-molded plastic packaged cascode broadband GaN LNA Monolithic Microwave Integrated Circuit (MMIC) with resistive feedback fabricated with 0.25 μm GaN HEMT technology. The single stage QFN packaged GaN LNA MMIC achieves a bandwidth of 0.03–2.6 GHz with a typical gain of 11.5 dB and less than 1.5 dB noise figure. The low noise amplifier (LNA) design is based on a model of a concept transistor, the cascode transistor used in the design, that has not been fabricated previously. The concept transistor is fabricated for the first time along with the GaN LNA MMIC. The fabricated GaN LNA MMIC is housed in a 12-lead 3 × 3 mm2 air cavity QFN over-molded plastic package and mounted on an application board. The measurements taken with the application board represent a good convergence with the design that is based on a concept transistor model. The measurement results and 50 Ω internal matching on both ports without the need for additional matching components make this LNA attractive for many applications.Item Open Access GaN based LNA MMICs for X-band applications(Institute of Electrical and Electronics Engineers, 2020) Zafar, Salahuddin; Osmanoğlu, Sinan; Öztürk, Mustafa; Çankaya, Büşra; Yılmaz, Doğan; Kashif, A. U.; Özbay, EkmelIn this paper, we report two low noise broadband amplifiers based on ABMN's AlGaN/GaN on SiC HEMT technology for X-band applications. Two design topologies, a single-stage (LNA-1) and a two-stage (LNA-2), have been investigated. LNA-1 and the first stage of LNA-2 is based on common source (CS) with inductive source degeneration topology. LNA-1 has a flat gain response of ±1.4 dB gain variation with a gain greater than 8 dB for 9 V drain voltage and 100 mA/mm drain current. Input return loss better than 9.8 dB and output return loss better than 12.8 dB have been achieved. The simulated value of noise figure for this design is less than 1.4 dB. In LNA-2 design, a two-stage topology is implemented to enhance amplifier's gain. The simulated values for LNA-2 show a gain greater than 16.8 dB with ±2.9 dB gain variation. Input and output return loss values are better than 8.8 dB and 10 dB, respectively. The value of noise figure for this design is less than 1.7 dB in the desired frequency range. Both designs, having state-of-the art small dimensions, are suitable for their potential applications for space communications, Radar, satellite communications etc.Item Open Access A Two stage x-band low noise amplifier optimized for minimum noise application(Bilkent University, 2015) Yılmaz, MerveLow Noise Amplifiers (LNA) are used as the first stage of any radio frequency receiver or any sensitive application requiring detection of very small signals with the minimum possible additional noise in order to get maximum signal-to-noise ratio at the output which also provide large enough gain to supersede the noise added by the following stages. An X-Band two stage low noise amplifier operating in the 8.2-8.4 GHz frequency band with active bias network by using microstrip technology is studied. The first stage of the LNA is designed to minimize the noise figure and the second stage of the amplifier is designed to obtain the necessary gain. The input match is optimized for better noise figure and to obtain reasonable input coupling. Total gain is kept above a certain value in order not to degrade the total noise figure of the whole cascaded system. Stability is obtained without sacrificing the in-band gain. Agilent’s ADS tool is used to simulate and Altium Designer tool is used for PCB design. The measurement results are compared with simulation results and the comparison shows good agreement.