Abstract
This paper presents the design, fabrication, and measurement of a 3 GHz single-stage discrete bipolar junction transistor (BJT) low-noise amplifier (LNA) for S-band wireless communication applications. To minimize parasitic effects, simplify fabrication, and enable post-production tuning, the proposed design employs via-free open-stub microstrip matching networks and transmission-line biasing in place of conventional lumped components. Source and load terminations are selected from constant-gain and stability circles, synthesized through a double-stub approach, and validated using circuit/electromagnetic (EM) co-simulation in AWR and Sonnet. A prototype was implemented on a 60 mil RO4003C substrate and biased at VCE = 3 V, IC ≈ 15 mA. Measured performance includes 9.2 dB gain, a 1.5 dB noise figure (NF) at 3 GHz, and input VSWR < 2 across 2.7–3.3 GHz (≈20% fractional bandwidth). Two-tone testing with Δf ≈ 2 MHz confirms an IIP3 of −11 ± 5 dBm. The proposed work makes three key contributions: (i) it minimizes vias and lumped parts while maintaining wide bandwidth, (ii) it provides a practical workflow for termination selection based on stability and gain circles, and (iii) it demonstrates a low-cost, fabrication-friendly design with measured validation. These results confirm the LNA’s suitability for compact, wideband receiver front-ends in satellite communication, wireless backhaul, radar, and IoT systems.
References
- Cadence. (2025). AWR design environment platform. Retrieved August 18, 2025, from https://www.cadence.com/awr
- Charchian, M., Zakeri, B., & Miar-Naimi, H. (2015). Wideband noise figure low noise amplifier design for 3.5–4.5 GHz. In 2015 2nd International Conference on Knowledge-Based Engineering and Innovation (KBEI) (pp. 589–594). Tehran, Iran. https://doi.org/10.1109/KBEI.2015.7436111
- Edwards, M. L., & Sinsky, J. H. (1992). A new criterion for linear 2-port stability using a single geometrically derived parameter. IEEE Transactions on Microwave Theory and Techniques, 40(12), 2303–2311. https://doi.org/10.1109/22.179894
- Gonzalez, G. (1996). Microwave transistor amplifiers: Analysis and design (2nd ed.). Upper Saddle River, NJ: Prentice Hall. ISBN:978-0-13-254335-4
- Honnaiah, P. J., & Reddy, S. (2019). Design of a linear LNA (BFP640) on RO4003C near 3.2 GHz. DOI:10.13140/RG.2.2.26776.60165
- Keim, R. (2023, April 21). Learn stub tuning with a Smith chart. All About Circuits. Retrieved August 18, 2025, from https://www.allaboutcircuits.com
- Keysight Technologies. (2001). Noise figure measurement accuracy: The Y-factor method (Application Note 5952-3706). Retrieved August 18, 2025.
- Maas, S. A. (2003). Nonlinear microwave and RF circuits (2nd ed.). Norwood, MA: Artech House. ISBN: 9781580534840
- Matthaei, G. L., Young, L., & Jones, E. M. T. (1964). Microwave filters, impedance-matching networks, and coupling structures. New York, NY: McGraw-Hill. ISBN: 0-89006-09901
- Munir, A., Taryana, Y., Yunus, M., Nusantara, H., & Effendi, M. R. (2019). Two-stage S-band LNA development using non-simultaneous conjugate match technique. Journal of ICT Research and Applications, 13(3), 213–227. https://doi.org/10.5614/ITBJ.ICT.RES.APPL.2019.13.3.3
- Novak, S. (1997). Practical aspects of the transmission line stub matching in microstrip. Radioengineering, 6(2), 14–17. https://www.radioeng.cz/fulltexts/1997/97_02_03.pdf
- NXP Semiconductors. (2025). BFG424F—NPN 25-GHz wideband transistor [Data sheet]. Retrieved August 18, 2025. https://www.nxp.com/docs/en/data-sheet/BFG424F.pdf
- Ottosson, E. (2006). Design and implementation of an ultra-wideband LNA (Master’s thesis). Linköping University, Linköping, Sweden. https://www.diva-portal.org/smash/get/diva2:650287/FULLTEXT01.pdf
- Pozar, D. M. (2012). Microwave engineering (4th ed.). Hoboken, NJ: Wiley. ISBN: 978-0-470-63155-3
- Rahimian, A., & Pakdehi, D. M. (2014). Design and realization of an S-band microwave low-noise amplifier for wireless RF subsystems. https://doi.org/10.48550/arXiv.1409.2141
- Rogers Corporation. (2025). RO4003C™ laminates (Dk ≈ 3.55) [Data sheet]. Retrieved August 18, 2025. https://www.rogerscorp.com/advanced-electronics-solutions/ro4000-series-laminates/ro4003c-laminates
- Rollett, J. M. (1962). Stability and power-gain invariants of linear twoports. IRE Transactions on Circuit Theory, 9(1), 29–32. DOI: 10.1109/TCT.1962.1086854
- Sadeque, M. G., Yusoff, Z., Roslee, M., Hashim, S. J., & Mohd Marzuki, A. S. (2021). Analysis and design of the biasing network for a 1-GHz-bandwidth RF power amplifier. Indonesian Journal of Electrical Engineering and Computer Science, 24(1), 308–316. https://doi.org/10.11591/ijeecs.v24.i1.pp308-316
- Savci, H. S., Wang, Z., Sula, A., Dogan, N. S., & Arvas, E. (2006, May). A 1-V UHF low noise amplifier for ultralow-power applications. In 2006 IEEE International Symposium on Circuits and Systems (pp. 4-pp). IEEE. DOI: 10.1109/ISCAS.2006.1693628
- Shakibmehr, M., & Lotfizad, M. (2017). Design of an S-band ultra-low-noise amplifier with frequency-band switching capability. Journal of Electrical and Computer Engineering Innovations, 5(1), 13–18. https://doi.org/10.22061/JECEI.2017.624
- Sonnet Software. (2025). User’s guide: The analysis engine (em) (Version 18). Retrieved August 18, 2025. https://www.sonnetsoftware.com/support/help-18/users_guide
- Zhao, J., Wang, F., Yu, H., Zhang, S., Wang, K., Liu, C., Wan, J., Liang, X., & Yan, Y. (2022). Analysis and design of a wideband low-noise amplifier with bias and parasitic parameters derived wide bandpass matching networks. Electronics, 11(4), 633. https://doi.org/10.3390/electronics11040633
Abstract
Bu çalışma, S-band kablosuz haberleşme uygulamaları için 3 GHz’de çalışan tek kademeli ayrık bipolar jonksiyon transistör (BJT) düşük gürültü yükseltecinin (LNA) tasarımını, üretimini ve ölçümlerini sunmaktadır. Parazitik etkileri en aza indirmek, üretimi basitleştirmek ve üretim sonrası ayarlamaya olanak tanımak amacıyla önerilen tasarımda, geleneksel devre elemanları yerine via-free açık uçlu mikroşerit uyumlaştırma ağları ve iletim hattı tabanlı besleme yapısı kullanılmıştır. Kaynak ve yük uçları, sabit kazanç ve kararlılık çemberlerinden seçilmiş, çift-stub sentezi yöntemiyle tasarlanmış ve AWR ile Sonnet ortamlarında devre/ elektromanyetik (EM) ortak benzetim ile doğrulanmıştır. Tasarlanan prototip 60 mil RO4003C alt tabakası üzerinde gerçekleştirilmiş ve VCE = 3 V, IC ≈ 15 mA altında beslenmiştir. Ölçüm sonuçları; 3 GHz’de 9.2 dB kazanç, 1.5 dB gürültü faktörü (NF) ve 2.7–3.3 GHz aralığında (≈%20 FBW) giriş VSWR < 2 değerlerini göstermektedir. Δf ≈ 2 MHz iki tonlu testler sonucunda IIP3 ≈ −11 ± 5 dBm olarak elde edilmiştir. Bu çalışma üç temel katkı sunmaktadır: (i) via ve ayrık devre elemanlarını en aza indirerek geniş bant performansını korumak, (ii) kararlılık ve kazanç çemberlerine dayalı pratik bir uç seçimi yöntemi sağlamak, (iii) düşük maliyetli ve üretim uygun bir tasarımın ölçümle doğrulanmış başarımını ortaya koymak. Sonuçlar, önerilen LNA’nın uydu haberleşmesi, kablosuz backhaul, radar ve IoT sistemleri gibi kompakt ve geniş bant alıcı ön uçları için uygun olduğunu göstermektedir.
References
- Cadence. (2025). AWR design environment platform. Retrieved August 18, 2025, from https://www.cadence.com/awr
- Charchian, M., Zakeri, B., & Miar-Naimi, H. (2015). Wideband noise figure low noise amplifier design for 3.5–4.5 GHz. In 2015 2nd International Conference on Knowledge-Based Engineering and Innovation (KBEI) (pp. 589–594). Tehran, Iran. https://doi.org/10.1109/KBEI.2015.7436111
- Edwards, M. L., & Sinsky, J. H. (1992). A new criterion for linear 2-port stability using a single geometrically derived parameter. IEEE Transactions on Microwave Theory and Techniques, 40(12), 2303–2311. https://doi.org/10.1109/22.179894
- Gonzalez, G. (1996). Microwave transistor amplifiers: Analysis and design (2nd ed.). Upper Saddle River, NJ: Prentice Hall. ISBN:978-0-13-254335-4
- Honnaiah, P. J., & Reddy, S. (2019). Design of a linear LNA (BFP640) on RO4003C near 3.2 GHz. DOI:10.13140/RG.2.2.26776.60165
- Keim, R. (2023, April 21). Learn stub tuning with a Smith chart. All About Circuits. Retrieved August 18, 2025, from https://www.allaboutcircuits.com
- Keysight Technologies. (2001). Noise figure measurement accuracy: The Y-factor method (Application Note 5952-3706). Retrieved August 18, 2025.
- Maas, S. A. (2003). Nonlinear microwave and RF circuits (2nd ed.). Norwood, MA: Artech House. ISBN: 9781580534840
- Matthaei, G. L., Young, L., & Jones, E. M. T. (1964). Microwave filters, impedance-matching networks, and coupling structures. New York, NY: McGraw-Hill. ISBN: 0-89006-09901
- Munir, A., Taryana, Y., Yunus, M., Nusantara, H., & Effendi, M. R. (2019). Two-stage S-band LNA development using non-simultaneous conjugate match technique. Journal of ICT Research and Applications, 13(3), 213–227. https://doi.org/10.5614/ITBJ.ICT.RES.APPL.2019.13.3.3
- Novak, S. (1997). Practical aspects of the transmission line stub matching in microstrip. Radioengineering, 6(2), 14–17. https://www.radioeng.cz/fulltexts/1997/97_02_03.pdf
- NXP Semiconductors. (2025). BFG424F—NPN 25-GHz wideband transistor [Data sheet]. Retrieved August 18, 2025. https://www.nxp.com/docs/en/data-sheet/BFG424F.pdf
- Ottosson, E. (2006). Design and implementation of an ultra-wideband LNA (Master’s thesis). Linköping University, Linköping, Sweden. https://www.diva-portal.org/smash/get/diva2:650287/FULLTEXT01.pdf
- Pozar, D. M. (2012). Microwave engineering (4th ed.). Hoboken, NJ: Wiley. ISBN: 978-0-470-63155-3
- Rahimian, A., & Pakdehi, D. M. (2014). Design and realization of an S-band microwave low-noise amplifier for wireless RF subsystems. https://doi.org/10.48550/arXiv.1409.2141
- Rogers Corporation. (2025). RO4003C™ laminates (Dk ≈ 3.55) [Data sheet]. Retrieved August 18, 2025. https://www.rogerscorp.com/advanced-electronics-solutions/ro4000-series-laminates/ro4003c-laminates
- Rollett, J. M. (1962). Stability and power-gain invariants of linear twoports. IRE Transactions on Circuit Theory, 9(1), 29–32. DOI: 10.1109/TCT.1962.1086854
- Sadeque, M. G., Yusoff, Z., Roslee, M., Hashim, S. J., & Mohd Marzuki, A. S. (2021). Analysis and design of the biasing network for a 1-GHz-bandwidth RF power amplifier. Indonesian Journal of Electrical Engineering and Computer Science, 24(1), 308–316. https://doi.org/10.11591/ijeecs.v24.i1.pp308-316
- Savci, H. S., Wang, Z., Sula, A., Dogan, N. S., & Arvas, E. (2006, May). A 1-V UHF low noise amplifier for ultralow-power applications. In 2006 IEEE International Symposium on Circuits and Systems (pp. 4-pp). IEEE. DOI: 10.1109/ISCAS.2006.1693628
- Shakibmehr, M., & Lotfizad, M. (2017). Design of an S-band ultra-low-noise amplifier with frequency-band switching capability. Journal of Electrical and Computer Engineering Innovations, 5(1), 13–18. https://doi.org/10.22061/JECEI.2017.624
- Sonnet Software. (2025). User’s guide: The analysis engine (em) (Version 18). Retrieved August 18, 2025. https://www.sonnetsoftware.com/support/help-18/users_guide
- Zhao, J., Wang, F., Yu, H., Zhang, S., Wang, K., Liu, C., Wan, J., Liang, X., & Yan, Y. (2022). Analysis and design of a wideband low-noise amplifier with bias and parasitic parameters derived wide bandpass matching networks. Electronics, 11(4), 633. https://doi.org/10.3390/electronics11040633
Details
| Primary Language | English |
|---|---|
| Subjects | Engineering Electromagnetics |
| Journal Section | Research Article |
| Authors | |
| Publication Date | December 3, 2025 |
| Submission Date | August 27, 2025 |
| Acceptance Date | October 20, 2025 |
| Published in Issue | Year 2025 Volume: 28 Issue: 4 |
