Ku-Band InP LNA design based on device model optimization

국문 초록 (Abstract)

이 논문에서는 정의되지 않은 파운드리의 공정 서비스를 설계자에게 정확하게 제공하기 위해서 공정 서비스를 PDK로 변환하는 절차 중 하나인 능동 소자 모델링을 소개한다. 특히, Angelov-GaN model를 사용하여 노이즈 특성에 중점을 두고 LNA용 InP HEMT를 모델링하는 방법을 제안하고 검증하였다. 모델링 연구는 양산 공정을 개발 중인 국내 InP 공정 업체와 연구를 시작하였다. 노이즈 모델에 대한 검증은 Focus의 노이즈 측정장비를 이용했고 모델이 갖는 NF_min과 Gamma_opt 가 측정값과 유사함을 확인하였다. 또한, 모델한 HEMT device로 Ku-band에서 LNA를 설계 후 측정하였다. 모델링된 InP HEMT는 0.8Gm_max (V_d=0.8V, V_g=0V)에서 동작을 목표로 하였으며, 이때 소자의 MAG는 12dB(at 12GHz), NF_min는 0.5dB(at 12GHz)이다. 상용화 된 제품보다 좋은 노이즈 특성을 갖도록 LNA를 설계하였다. 시뮬레이션 결과 이득은 25dB 이상, 잡음 지수는 1.2dB 이하로 나왔고 측정 결과 10GHz~14GHz 대역에서 이득은 25dB 이상, 잡음 지수는 1.2dB 이하를 실제로 얻을 수 있었다. 설계한 값과 유사한 결과를 얻어 Angelov-GaN을 이용한 노이즈 모델 검증을 하였다. 아직 연구 초기 단계라 완벽하지는 않으나 디바이스 모델에 대한 연구가 더욱 발전한다면 국내 화합물 MMIC 파운드리와 국내 5G·6G 산업 발전에 기여할 수 있을 것으로 생각된다.

다국어 초록 (Multilingual Abstract)

In this paper, active device modeling, one of the procedures for converting process services into PDK (Physical Design Kit), is introduced in order to accurately provide designers with undefined foundry process services. In particular, a method for modeling InP HEMT for LNA was proposed and verified with an emphasis on noise characteristics using the Angelov-GaN model. The reason for using the Angelov-GaN model is that a noise model is possible and it is the most used model in the idustry. The Angelov-GaN model has several methods in the process of matching measured values and model values. The method differs depending on which parameter is used and the value of the parameter at that time. Therefore, when doing a noise model, I would like to suggest the parameters(R_g, L_w, IJ, R_s) and tuning process that should be focused on. We started research with a domestic InP process company that is currently developing a mass production process. The device used for modeling was an InP device with W_g (gate width) = 50um, NF (Number of Fingers) = 2, and L_g (gate length) = 100nm. In addition, modeling was performed between 3 GHz and 30 GHz, which is the most used band for compound semiconductors. For the verification of the noise model, Focus's noise measurement equipment was used, and it was confirmed that the NF_min and Gamma_opt of the model were similar to the measured values. In addition, the noise and gain characteristics of the LNA were confirmed by designing and measuring the LNA in Ku-band with the modeled HEMT device. The modeled InP HEMT targets LNA operation at the 0.8Gm_max point (V_d = 0.8V, V_g = 0V), at which time the device's MAG is 12dB (at 12GHz) and NF_min is 0.5dB (at 12GHz). Compared to currently commercialized products, LNA was designed to have better noise characteristics. As a result of the simulation, the gain was more than 25dB and the noise figure was less than 1.2dB. As a result of the measurement, the gain was more than 25dB and the noise figure was less than 1.2dB in the 10GHz~14GHz band. Results similar to the designed values could be obtained, and the noise model using Angelov-GaN could be verified. It is still in the early stages of research, so it is not perfect, but if the research on the device model is further developed, it is thought that it can contribute to the development of the domestic compound MMIC foundry and the domestic 5G/6G industry.

목차 (Table of Contents)

• 1. Introduction 1
• 2. InP HEMT Modeling 9
• 2.1 Angelov-GaN model 9
• 2.1.1 Angelov-GaN as empirical compact model 9
• 2.1.2 Concept of Angelov-GaN model 10
• 2.1.3 Modeling sequence 13
• 2.1.4 Angelov-GaN DC fitting 15
• 2.1.5 Angelov-GaN RF fitting 21
• 3. Noise model verification 25
• 3.1 Noise model verification through measurement 25
• 3.1.1 Noise measurement set up 25
• 3.1.2 Parameters about noise model 26
• 3.1.3 Noise model with R_g 27
• 4. Design and measurement of passive element and LNA 30
• 4.1 Design passive element and PCM result. 30
• 4.1.1 Design capacitor and PCM result 30
• 4.1.2 Design inductor and PCM result. 34
• 4.2 Design and measure LNA 38
• 4.2.1 Design 1st stage LNA 38
• 4.2.2 Design 2-stage cascade LNA and simulation result 41
• 4.2.3 Comparison of measurement and simulation result 45
• 5. Conclusion 50
• References 51
• 국문초록 54