Browsing by Author "Gürdal, Armağan"

Now showing 1 - 4 of 4

Open Access
60W stacked-HEMT based asymmetric X-band GaN SPDT switch for single chip T/R modules
(IEEE - Institute of Electrical and Electronics Engineers, 2023-10-25) Ertürk, Volkan; Gürdal, Armağan; Çankaya Akoğlu, Büşra; Özbay, Ekmel
This paper presents a high-power, asymmetric single-pole double-throw (SPDT) monolithic microwave integrated circuit (MMIC) switch using high electron mobility transistors (HEMT) with AlGaN/GaN technology for single chip X-band T/R modules. The SPDT switch is designed in series-shunt topology for high-power handling and low-loss performance. For high-power handling, shunt-stacked HEMTs on the transmit (Tx) path and series-stacked HEMTs on the receive (Rx) path are used. In its Tx mode, the switch has achieved an insertion loss better than 0.75 dB throughout the 6-13 GHz bandwidth with a return loss of 14 dB and an isolation of 28 dB. It can handle more than 60 W RF input power at 0.1 dB compression. In its Rx mode, the switch can receive signals with an insertion loss lower than 1.15 dB with 14 dB return loss and 19 dB isolation. With its low insertion and high-power handling capacity from C-band to Ku-band, this switch shows state-of-the-art performance for communication systems.
Open Access
A high gain and high efficiency 15 W X-Band GaN power amplifier MMIC
(IEEE, 2019) Gürdal, Armağan; Özipek, Ulaş; Sütbaş, Batuhan; Özbay, Ekmel
An X-band microstrip power amplifier MMIC based on our 0.25 μm AlGaN/GaN on SiC process technology is presented in this work. Fabrication steps, HEMT structure and typical device performance are demonstrated. Design procedure of the three-stage power amplifier MMIC with a compact size of 4.7 mm × 2.7 mm is described. Small-signal measurements of the fabricated MMICs typically show 36 dB gain with 5 dB ripple and input/output return losses better than 16 dB and 7 dB from 8.5 GHz to 12 GHz band, respectively. Typical output power of 15 W at 6 dB compression with 37%-44% power added efficiency is achieved under pulsed operation. MMIC power measurements performed at different base plate temperatures and bias conditions are also provided. This design exhibits significantly higher gain and much better input return loss compared to MMICs in the literature with similar size, efficiency and output power parameters.
Open Access
X Band GaN Based MMIC power amplifier with 36.5dBm P1-dB for space applications
(IEEE, 2018) Gürdal, Armağan; Yilmaz, Burak Alptug; Cengiz, Ömer; Şen, Özlem; Özbay, Ekmel
An X-Band Monolithic Microwave Integrated Circuit (MMIC) High Power Amplifier (HPA) with coplanar waveguide (CPW) based on AIGaN/GaN on SiC technology is presented in this paper. Coplanar waveguide technology (CPW) is chosen for the simplicity and reduced cost of fabrication since CPW process has no via. High Electron Mobility Transistors (HEMTs) are matched for the 8 GHz-8.4GHz frequency band for maximum output power. The Amplifier has a small signal gain over 10 dB, output power of 36.5dBm at 1 dB gain compression point (P1dB) and 40% power added efficiency (P AE) at (PldB) in the desired frequency band (8 GHz-8.4 GHz) with Vds = 30V.
Open Access
X band GaN based MMIC power amplifier with 36.5dBm P1-dB for space applications
(IEEE, 2018) Gürdal, Armağan; Yılmaz, Burak Alptuğ; Cengiz, Ömer; Sen, Özlem; Özbay, Ekmel
An X-Band Monolithic Microwave Integrated Circuit (MMIC) High Power Amplifier (HPA) with coplanar waveguide (CPW) based on AlGaN/GaN on SiC technology is presented in this paper. Coplanar waveguide technology (CPW) is chosen for the simplicity and reduced cost of fabrication since CPW process has no via. High Electron Mobility Transistors (HEMTs) are matched for the 8 GHz-8.4GHz frequency band for maximum output power. The Amplifier has a small signal gain over 10 dB, output power of 36.5dBm at 1 dB gain compression point (P1dB) and 40% power added efficiency (PAE) at (PldB) in the desired frequency band (8 GHz-8.4 GHz) with Vds = 30V.