TY - GEN A1 - Kared, Trusha A1 - Silaghi, Helga A1 - Rudolph, Matthias A1 - Silaghi, Andrei A1 - Rohde, Ulrich L. T1 - Design of a fixed IF down-conversion double-balanced mixer for UHF band applications T2 - Sensors N2 - This paper presents a new SiGe HBT-based high dynamic range double-balanced down-conversion differential mixer. Operating within the 0.5 GHz to 1.8 GHz range, the suggested mixer is appropriate for a variety of applications, such as cellular base stations, satellite communication (SATCOM), and military radar. The down-conversion mixer is made up of a single-ended to a differential-balanced radiofrequency (RF) stage, a dual feedback linearization for the RF stage, a local oscillator (LO) balun, LO mixing cores, and a fixed intermediate frequency (IF)-tuned circuit connected between two outputs to serve as a load at 145 MHz. Compared to earlier research in the literature, the measured SSB noise figure is approximately 7 dB ± 0.4 dB, and the measured conversion gain is approximately 12 dB ± 1 dB for a full band of operation. The mixer achieves a good return loss of over 8 dB for an RF and LO port in the desired band and a measured return loss of over 18 dB at 145 MHz and IF frequency. Furthermore, the design achieved an RF-to-IF isolation of greater than 35 dB, LO feedthrough, and an LO leakage isolation of better than 50 dB. Lastly, the measured third-order intercept point was found to be +4.7 dBm, and the 1 dB compression point was approximately −8 dBm. These results demonstrate good linearity performance. KW - Military radar KW - Satellite communication (SATCOM) KW - Cellular base stations KW - Mixer KW - Lo balun KW - Impedance matching Y1 - 2025 U6 - https://doi.org/10.3390/s25030608 SN - 1424-8220 VL - 25 IS - 3 SP - 1 EP - 29 PB - MDPI CY - Basel ER - TY - GEN A1 - Beleniotis, Petros A1 - Andrei, Cristina A1 - Zervos, Christos A1 - Rohde, Ulrich L. A1 - Rudolph, Matthias T1 - GaN trap model extraction based on MHz load-line measurements T2 - 2025 IEEE/MTT-S International Microwave Symposium - IMS 2025 N2 - The extraction of model parameters for GaN HEMTs is a challenging task that typically requires a comprehensive series of pulsed measurements to ensure that the resulting model is both accurate and convergence-stable. This study introduces, for the first time, an extraction procedure that utilizes I-V curves generated by MHz load-line measurements, effectively replacing the complex and time-intensive pulsed measurements. A drain-lag model extraction was based on load-line I-V curves and validated along with a pulsed-IV-based model through RF large-signal simulations, demonstrating excellent performance. KW - GaN KW - Compact model KW - Load-line KW - Model parameter extraction Y1 - 2025 SN - 979-8-3315-1409-9 U6 - https://doi.org/10.1109/IMS40360.2025.11104000 SP - 1059 EP - 1062 PB - IEEE CY - Piscataway, NJ ER - TY - GEN A1 - Beleniotis, Petros A1 - Andrei, Cristina A1 - Rohde, Ulrich L. A1 - Rudolph, Matthias T1 - Determining GaN HEMT trap models from MHz load-line measurement — synthesis and evaluation T2 - 2025 16th German Microwave Conference (GeMiC) N2 - The modeling of GaN HEMTs is closely associated with pulsed measurements, which are essential for extracting model parameters related to trapping and thermal effects. However, these characterizations are often hindered by high costs and the time-intensive nature of the measurement process. In this paper, we present and evaluate a novel approach for trap model extraction that utilizes MHz load-line measurements. Our analysis includes a comparative study of the measurements and a demonstration of modeling based on the proposed methodology. KW - Compact modeling KW - Load-line KW - Model parameter extraction KW - GaN HEMT KW - ASM-HEMT Y1 - 2025 SN - 978-3-9820397-4-9 U6 - https://doi.org/10.23919/GeMiC64734.2025.10978988 SP - 451 EP - 454 PB - IEEE CY - Piscataway, NJ ER -