MMIC design activities at ASIAA Chau-Ching Chiong, Ping-Chen Huang, Yuh-Jing Huang, Ming-Tang Chen (ASIAA), Ho-Yeh Chang (NCUEE), Ping-Cheng Huang, Che-Chung Kuo, Che-Chiang Kuo, Chau-Chieh Li, Huei Wang (NTUEE), and Eric Bryerton (NRAO) InGaAs mHEMTInGaP/GaAs HBT VCO Freq. (GHz) (Design) BW Power (dBm) Phase noise (dBc/Hz) Freq. (GHz) (Measured) BW Power (dBm) Phase noise (dBc/Hz) A25.5 to %-3 ~ to 28.49%-10 ~ ~ -100 B17.0 to %0 ~ to %-10 ~ ~ -90 C13.7 to %7 ~ to %1 ~ ~ -80 D12.3 to %2 ~ to 15.07%-8 ~ ~ -85 E12.8 to % to %-5 ~ ~ -95 TechnologyFreq. (GHz) Tuning range P out (dBm) Dissipation (mW) Phase 1 MHz (dBc/Hz) FOM*Reference GaAs/InGaP HBT 289% VCO A 2025% VCO B 1723% VCO C 147% VCO D 1321% VCO E InP HBT18.644% [1] InAlAs/InGaAs HBT 186% [2] GaAs/InGaP HBT252% [3] SiGe HBT21.55% [4] CMOS186% [5] Reference [1] Diahanshahi, H., Saniei, N., Voinigescu, S. P., Maliepaard, M. C., and Salama, C. A. T., IEEE Radio Freq. Integrated Circuits Symposium, [2] Kobayashi K. W., Tran, L. T., Oki, A. K., Block, T., Streit, D. C., IEEE Microwave and Guided Wave Letters, vol. 5, no. 9, Sept New mHEMT technology is employed for its low cost and long life- time, with compatible noise performance with InP HEMT. Wideband LNA covering 30 to 45 GHz, IF amplifier covering 4 to 12 GHz, and mixer for Q-band are fabricated using mHEMT. We initiate a project to find an alternative solution to commonly used Gunn/YIG oscillator in microwave/millimeterwave local oscillator (LO) system. InGaP/GaAs HBT process is adapted due to its low 1/f noise. Five VCOs are designed in “double-tuned” concept, in which two varactors are employed to have wide tuning bandwidth and good linearity in Vtune./Freq. curve. Overview Amplifiers, mixers and oscillators are key components in modern radio, millimeter and submillimeter wave re- ceiving system. They are also our focus in MMIC design activities at ASIAA. The work is summarized in two categories: (1) Low noise amplifier (LNA), mixer and IF amplifier (4-12 GHz) using 0.15 um InGaAs mHEMT, and (2) Voltage-controlled oscillator (VCO) and PLL components using 2um InGaP/GaAs HBT. Fig. 1. Chip photo of the 2-stage mHEMT Q-band LNA. Fig. 2. S-parameters of measured (thick line) and simulated (thin line) results of LNA chip under Vds1 = Vds2 = 2 V, Vgs1 = Vgs2 = -0.2 V. Fig. 3. Noise figure from measurement and simulation at room temperature. Fig. 4. 3D view of LNA housing. Only half of the housing is shown in the figure. Power (dBm) [3] Bao, M., Li, Y., Jacobsson, H., IEEE Microwave and Wireless Components Letters, Vol. 15, Nov. 2005, pp [4] Bao, M., Li, Y., Jacobsson, H., IEEE Journal of solid-state circuits, Vol. 39, pp , Aug [5] Le Grand de Mercey, G., Proc. Eur. Solid-State Circuits, pp , The measured results of the 2-stage LNA design are shown in Fig. 2 and 3. From Fig. 2 it shows fairly good gain response (S 21 ) above 30 GHz, while bad return loss (S 11 /S 22 ) limits its operation bandwidth. Noise figure is measured at room temperature (Fig. 3). To evaluate LNA performance at low temperature, LNA housing is in fabrication (Fig. 4). Fig. 5 shows the results of Q-band mixer. The design goal of this mixer is to operate at 30 to 45 GHz (RF signal) and 27 to 33 GHz (LO signal), with 4-12 GHz IF bandwidth and -10 dB conversion gain. Measured results shows lower conversion gain by ~ 3 dB. Isolation between RF/LO ports is better than 20 dB. Gain and return loss of the 2-stage IF 4-12 GHz amplifier are shown in Fig. 6. Fig. 6. S-parameters of measured (thick lines) and simulated (thin lines) results of IF amp. chip under Vds1/Ids1= 1 V / 64 mA and Vds2/Ids2= 2 V / 34 mA. Fig. 5. Measured and simulated conversion gain of Q-band mixer. LO input power is 15 dBm. Layout of VCO B and its measurement results are shown in Fig. 7. Fig. 7b shows good prediction on oscillating frequency and output power from harmonic balance simulator using Gummel-Poon model. Fig. 7c shows the phase noise performance, measurement shows fluctuation within tuning range. As a comparison, the specification of ALMA is also shown in the figure. The table below gives a common way to evaluate VCO performance in term of figure-of-merit (FOM), our VCOs are compatible to the others. (a) (b) (c) Fig. 7. (a) layout of VCO B, chip size is 2mm x 1.5mm; (b) and (c): measured and simulated results of oscillating frequency, power and phase noise as function of tuning voltage (Vtune).