A Research Of Short-millimeter Wave InP DHBT Monolithic Amplifier

Short millimeter-wave/terahertz system is widely used in radar, electronic warfare, communication, and imaging technology application, and is the international research focus and the development leading edge in the field of microwave technique, whose prospect is very broad. As one of the key components, single chip amplifier is the key of the research. Indium phosphide based double heterojunction transistor has high working frequency, high power density, large breakdown voltage, good linearity, strong radiation-hardened ability advantages in ultra high frequency, which is very suitable for production of short millimeter wave monolithic amplifier. So a research of InP DHBT short milliter wave monolithic amplifier has important scientific value and practical significance.Main works are followed:Based on the small signal equivalent circuit model of InP DHBT, a 140~220 GHz MMIC amplifier is designed with ADS and HFSS co-simulation method. The research of matching networks, stability and bias network of the short millimeter wave monolithic amplifier are the key issues. Because the active gain is low and the insertion loss of the passive components is big, so the matching network, together with the bias network and the multi-stage structure is used in the circuit to get big gain. Bias circuit using λ/4 high impedance line, parallel grounding decoupling capacitor and stable resistance structure to ensure the normal work of the transistors and circuit stability. Simulated results show that the small signal gain is more than 10 d B in the range of 215 GHz~225 GHz, and reaches the maximum gain of 12 dB at 220 GHz. The power amplifier is on-wafer tested after fabrication, in the bias condition of Vce=1.5V and Ibb=500μA, the measurement results demonstrate that the small signal gain of the amplifier is greater than 8 d B in the range of 156.5GHz~179GHz, and reaches the maximum gain of 9.83 dB at 161 GHz, the input S11 is almost about-4 dB and the output S22 is better than-10 dB, which has reached the domestic leading level.Based on the large signal equivalent circuit model of InP DHBT, a 140 GHz MMIC power amplifier is designed. The matching network, together with the bias network and the multi-stage structure are used in the circuit to get big gain. Four-way Wilkinson power synthesis technology is used in the circuit to improve the power output. Simulated results show that the power amplifier has small signal gain up to 10 dB, and the output power is greater than 10 dBm in the range of 135~145 GHz. The saturated output power in 140 GHz is 10.49 dBm, and the associated power gain is 5.49 dB, of which achieves maximum output power 10.59 dBm at 135 GHz.