rus
Issue #9/2018
Abolduev Igor M., Valamin Evgeniy A., Dorofeyev Alexei A., Zubkov A.M., Minnebaev Stanislav V., Tsarev Alexander V., Kuliev M.V.
GaN HEMT-based Voltage Controlled Oscillators
GaN HEMT-based Voltage Controlled Oscillators
Solid-state microwave oscillators are part of many microwave systems. In this paper we propose design solutions for three types of voltage controlled oscillators for different tuning ranges and consider the effect of HEMT design on the phase noise level.
Microwave sinusoidal signal oscillators are part of many microwave systems, such as radars, radio communication lines, navigation equipment, etc.
Main performance parameters of voltage controlled oscillators (VCO) are:
1. Output power.
2. Tuning range.
3. Tuning linearity.
4. Phase noise level.
Depending on its functions, oscillator could have high output power, low phase noise and wide tuning range.
In the current work, the following voltage controlled oscillators have been designed:
1. Standard design 50–1000MHz VCO (Fig. 1,2).
2. Hybrid VCO with 2–4GHz tuning range (Fig. 3,4).
3. Monolithic VCO with 8–12.5 tuning range (Fig. 5, 6).
Designed oscillators feature GaN HEMT with 250-µm gate width as an active device.
The use of a GaN HEMT as an active device in oscillators is one of the emerging trends in the semiconductor electronics. Parameter comparison of various stabilized oscillators is shown in Table 1. GaN HEMT-, GaAs pHEMT- and HBT-based VCOs comparison is shown in Table 2. It could be observed that AlGaN/GaN VCOs surpasses its AlGaAs/GaAs counterparts by output power performance and phase noise spectral density (PNSD).
Phase noise is one of the most important parameters of VCO. It is well known that phase noise level is dependent on Q-factor of the resonator and passive elements used, as well as on VCO active element [14]. We investigated the impact of transistor structure on the phase noise of the device. For this purpose we measured the dependence of VCOs` PNSD on frequency tuning in the range from 100Hz to 100kHz. Below are the dependencies of PNSD parameter of VCOs, based on three different transistor types:
1. Transistor with a field plate and source through-vias near the gate (Fig. 9).
2. Transistor with a field plate and source through-vias made on transistor periphery (Fig. 10).
3. Transistor without a field plate and with source through-vias made on transistor periphery (Fig. 11).
Presented curves show that transistor design has a strong influence on the phase noise of the device, which requires further study.
Apart from transistor design, phase noise levels are dependent on the quality of used semiconductors and dielectrics, as well as manufacturing technology.
Within the framework of our research, we designed and produced VCO evaluation sample with frequency range 70.80MHz based on GaN transistor (Fig. 12). Measured performance was in a good agreement with simulated performance (within 10 % error). Phase noise level values of this VCO are shown in Fig. 13. Noise level values at tuning range 100kHz correspond to the results of foreign analogues.
REFERENCES
1. Maree J., J. B. de Swardt, and P. W. van der Walt. “Low Phase Noise Cylindrical Cavity Oscillator”, in IEEE AFRICON, 2013, pp. 1–5.
2. P. Rice, et al. “A 10GHz Dielectric Resonator Oscillator Using GaN Technology”, in IEEE MTT-S Int. Microw. Symp. Dig., Fort Worth, TX, USA, 2004, pp. 1497–1500.
3. Florian C., Traverso P. A., Vannini G., and Filicori F. “Design of Low Phase Noise Dielectric Resonator Oscillators with GaInP HBT Devices Exploiting a Non-Linear Noise Model”, in IEEE MTT-S Int. Microw. Symp. Dig., Honolulu, HI, USA, 2007, pp. 1525–1528.
4. Mikael Hörberg, Thomas Emanuelsson, Szhau Lai, Thi Ngoc Do Thanh, Herbert Zirath and Dan Kuylenstierna. “Phase-Noise Analysis of an X-Band Ultra-Low Phase-Noise GaN HEMT Based Cavity Oscillator” IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, Vol. 63, № 8, AUGUST 2015.
5. Zirath H., Kozhuharov R., Ferndahl M. “Balanced Colpits-Oscillator MMICs Designed for Ultra-Low Phase Noise”, IEEE J. Solid-State Circuits, 2005, 40 (10), pp. 2077–2086.
6. Kuylenstierna D., Lai S., Bao M., Zirath H. “Design of Low Phase-Noise Oscillators and Wideband VCOs in InGaP HBT Technology”, IEEE Trans. Microw. Theory Tech., 2012, 60, (11), pp. 3420–3430.
7. Fard A., Andreani P. “An Analysis of 1/f2 Phase Noise in Bipolar Colpitts Oscillators (with a Digression on Bipolar Differential-Pair LC Oscillators)”, IEEE J. Solid-State Circuits, 2007, 42, (2), pp. 374–384.
8. Jacobsson H., Gevorgian S., Mokhtari M., et al.: “Low-Phase-Noise Low Power IC VCOs for 5–8-GHz Wireless Applications”, IEEE Trans. Microw. Theory Tech., 2000, 48, (12), pp. 2533–2539.
9. Shealy J. B., Smart J. A., Shealy J. R. “Low-Phase Noise AlGaN/GaN FET-based Voltage-Controlled Oscillators (VCOs)”, IEEE Microw. Wirel. Compon. Lett., 2001, 11, (6), pp. 244–245.
10. Kaper V. S., Tilak V., Kim H., et al.: “High-Power Monolithic AlGaN/GaN HEMT Oscillator”, IEEE J. Solid-State Circuits, 2003, 38, (9), pp. 1457–1461.
11. Xu H., Sanabria C., Pervez N. K., Keller S., Mishra U. K., York R. A. “Low Phase-Noise 5GHz AlGaN/GaN HEMT Oscillator Integrated with BaxSr1-xTiO3”.
12. Kong C., Li H., Chen X., Jiang S., Zhou J., Chen C. “A Monolithic AlGaN/GaN HEMT VCO Using BST Thin-Film Varactor”, IEEE Trans. Microw. Theory Tech., 2012, 60, (11), pp. 3413–3419.
13. Lai S., Kuylenstiema D., Horberg M., Rorsman N. “Accurate Phase-Noise Prediction for a Balanced Colpitts GaN HEMT MMIC Oscillator”, IEEE Trans. Microw. Theory Tech., 2013, 61, (11), pp. 3916–3926.
14. Guillermo Gonzales. “Foundation of Oscillator Circuit Design” ARTECH HOUSE INC., Norwood, MA 02063 2007.
Main performance parameters of voltage controlled oscillators (VCO) are:
1. Output power.
2. Tuning range.
3. Tuning linearity.
4. Phase noise level.
Depending on its functions, oscillator could have high output power, low phase noise and wide tuning range.
In the current work, the following voltage controlled oscillators have been designed:
1. Standard design 50–1000MHz VCO (Fig. 1,2).
2. Hybrid VCO with 2–4GHz tuning range (Fig. 3,4).
3. Monolithic VCO with 8–12.5 tuning range (Fig. 5, 6).
Designed oscillators feature GaN HEMT with 250-µm gate width as an active device.
The use of a GaN HEMT as an active device in oscillators is one of the emerging trends in the semiconductor electronics. Parameter comparison of various stabilized oscillators is shown in Table 1. GaN HEMT-, GaAs pHEMT- and HBT-based VCOs comparison is shown in Table 2. It could be observed that AlGaN/GaN VCOs surpasses its AlGaAs/GaAs counterparts by output power performance and phase noise spectral density (PNSD).
Phase noise is one of the most important parameters of VCO. It is well known that phase noise level is dependent on Q-factor of the resonator and passive elements used, as well as on VCO active element [14]. We investigated the impact of transistor structure on the phase noise of the device. For this purpose we measured the dependence of VCOs` PNSD on frequency tuning in the range from 100Hz to 100kHz. Below are the dependencies of PNSD parameter of VCOs, based on three different transistor types:
1. Transistor with a field plate and source through-vias near the gate (Fig. 9).
2. Transistor with a field plate and source through-vias made on transistor periphery (Fig. 10).
3. Transistor without a field plate and with source through-vias made on transistor periphery (Fig. 11).
Presented curves show that transistor design has a strong influence on the phase noise of the device, which requires further study.
Apart from transistor design, phase noise levels are dependent on the quality of used semiconductors and dielectrics, as well as manufacturing technology.
Within the framework of our research, we designed and produced VCO evaluation sample with frequency range 70.80MHz based on GaN transistor (Fig. 12). Measured performance was in a good agreement with simulated performance (within 10 % error). Phase noise level values of this VCO are shown in Fig. 13. Noise level values at tuning range 100kHz correspond to the results of foreign analogues.
REFERENCES
1. Maree J., J. B. de Swardt, and P. W. van der Walt. “Low Phase Noise Cylindrical Cavity Oscillator”, in IEEE AFRICON, 2013, pp. 1–5.
2. P. Rice, et al. “A 10GHz Dielectric Resonator Oscillator Using GaN Technology”, in IEEE MTT-S Int. Microw. Symp. Dig., Fort Worth, TX, USA, 2004, pp. 1497–1500.
3. Florian C., Traverso P. A., Vannini G., and Filicori F. “Design of Low Phase Noise Dielectric Resonator Oscillators with GaInP HBT Devices Exploiting a Non-Linear Noise Model”, in IEEE MTT-S Int. Microw. Symp. Dig., Honolulu, HI, USA, 2007, pp. 1525–1528.
4. Mikael Hörberg, Thomas Emanuelsson, Szhau Lai, Thi Ngoc Do Thanh, Herbert Zirath and Dan Kuylenstierna. “Phase-Noise Analysis of an X-Band Ultra-Low Phase-Noise GaN HEMT Based Cavity Oscillator” IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, Vol. 63, № 8, AUGUST 2015.
5. Zirath H., Kozhuharov R., Ferndahl M. “Balanced Colpits-Oscillator MMICs Designed for Ultra-Low Phase Noise”, IEEE J. Solid-State Circuits, 2005, 40 (10), pp. 2077–2086.
6. Kuylenstierna D., Lai S., Bao M., Zirath H. “Design of Low Phase-Noise Oscillators and Wideband VCOs in InGaP HBT Technology”, IEEE Trans. Microw. Theory Tech., 2012, 60, (11), pp. 3420–3430.
7. Fard A., Andreani P. “An Analysis of 1/f2 Phase Noise in Bipolar Colpitts Oscillators (with a Digression on Bipolar Differential-Pair LC Oscillators)”, IEEE J. Solid-State Circuits, 2007, 42, (2), pp. 374–384.
8. Jacobsson H., Gevorgian S., Mokhtari M., et al.: “Low-Phase-Noise Low Power IC VCOs for 5–8-GHz Wireless Applications”, IEEE Trans. Microw. Theory Tech., 2000, 48, (12), pp. 2533–2539.
9. Shealy J. B., Smart J. A., Shealy J. R. “Low-Phase Noise AlGaN/GaN FET-based Voltage-Controlled Oscillators (VCOs)”, IEEE Microw. Wirel. Compon. Lett., 2001, 11, (6), pp. 244–245.
10. Kaper V. S., Tilak V., Kim H., et al.: “High-Power Monolithic AlGaN/GaN HEMT Oscillator”, IEEE J. Solid-State Circuits, 2003, 38, (9), pp. 1457–1461.
11. Xu H., Sanabria C., Pervez N. K., Keller S., Mishra U. K., York R. A. “Low Phase-Noise 5GHz AlGaN/GaN HEMT Oscillator Integrated with BaxSr1-xTiO3”.
12. Kong C., Li H., Chen X., Jiang S., Zhou J., Chen C. “A Monolithic AlGaN/GaN HEMT VCO Using BST Thin-Film Varactor”, IEEE Trans. Microw. Theory Tech., 2012, 60, (11), pp. 3413–3419.
13. Lai S., Kuylenstiema D., Horberg M., Rorsman N. “Accurate Phase-Noise Prediction for a Balanced Colpitts GaN HEMT MMIC Oscillator”, IEEE Trans. Microw. Theory Tech., 2013, 61, (11), pp. 3916–3926.
14. Guillermo Gonzales. “Foundation of Oscillator Circuit Design” ARTECH HOUSE INC., Norwood, MA 02063 2007.
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