Xiaoxi Ning

A 79 GHz sub-harmonic mixer design using a 1 um InP DHBT technology

This paper presents a 79 GHz sub-harmonic mixer (SHM) design based on a self-developed 1 um InP DHBT process. In this design, a low frequency local oscillator (LO) input signal at 39.5 GHz is doubled to W-band and a radio frequency (RF) signal ranging from 80 GHz to 86 GHz is down-converted to the intermediate frequency (IF) band with a best conversion gain around 1 dB at 83 GHz. As the knowledge of authors, it is the first attempt to implement an InP DHBT based SHM with a LO doubler in W-band. Due to lacking of available RF sources, the testing is realized with one port of an output power fixed Vector Network Analyzer enhanced by a frequency up-conversion module.

A 20-dB gain W-band InP DHBT power amplifier

A two-stage double heterojunction bipolar transistor (DHBT) power MMIC fabricated in InP technology is realized using coplanar waveguide structure. The output cell unit consists of four parallel cascode fingers. Sixteen fingers are at output stage from which the power is combined. Broad-band, low-loss matching networks lead to high gain and high combining efficiency. The chip area is 1.5×1.7 mm2. Measurements show that small signal gain is above 20 dB over 75.5 GHz ~ 84.5 GHz frequency band. Simulated saturated power is 19.7 dBm @ 89 GHz and the actual output power is to be measured once the W-band power source arrive.

X-band 11.7-W, 29-dB gain, 42% PAE three-stage pHEMT MMIC power amplifier

This paper presents an X-band high gain and high power three-stage PHEMT monolithic microwave integrated circuit (MMIC) power amplifier (PA). Based on 0.15-μm GaAs power PHEMT technology, this PA is fabricated on a 2-mil thick wafer. While operating under 7.2 V and 3300 mA dc bias condition, the characteristics of 29.2-dB small signal gain, 11.7-W output power, and 42.2% power added efficiency at 9.2 GHz can be achieved.

An 89 GHz single-balanced mixer design in 1 um InP DHBT technology

This paper demonstrates an active single-balanced mixer with InP double heterojunction bipolar transistor (DHBT) process for direct down-conversion system at 89 GHz. Authors use Coplanar Waveguide (CPW) as on-chip transmission line and tune an on-chip CPW balun to allocate LO signal to the switch cell. Benefiting from its balanced structure, this mixer shows a LO port to RF port isolation above 20 dB in all W-band. Its conversion gain is up to 3 dB with a 3 dB RF bandwidth more than 10 GHz. With a 10 dBm LO signal, the RF input 1 dB compression point is higher than -4 dBm around 89 GHz. This mixer consumes 340 mW power with a +4 V supply. All wafers have been thinned to 100 um before measurements.

Compact, broadband waveguide-to-CPWG transition operating around 300 GHz

This letter presents a broadband monolithically integrated waveguide transition module designed for operating around 300 GHz. This transition module employs waveguide WR2.8 and utilizes dipole-based transitions from waveguide to CPWG. The dipole-based transition is designed and fabricated using InP terahertz monolithic integrated circuit (TMIC) technology, so as to be directly integrated monolithically on the TMIC chip, e.g. amplifier, instead of using bond-wires. The measured results show that the insertion loss of this transition is less than 1.5 dB from 285 to 309 GHz, and return loss is better than -9 dB in the whole operation frequency band (270-330 GHz). Moreover, the dipole-based transition has a compact size that is suitable for minimal assembly.

A full W-band low noise amplifier module for millimeter-wave applications

A full W-band low noise amplifier (LNA) module is designed and fabricated. A broadband transition is introduced in this module. The proposed transition is designed,optimized based on the results from numerical simulations. The results show that 1 dB bandwidth of the transition ranges from 61 to 117 GHz. For the purpose of verification,two transitions in back-to-back connection are measured. The results show that transmission loss is only about 0.9-1.7 dB. This transition is used to interface integrated circuits to waveguide components. The characteristic of the LNA module is measured after assembly. It exhibits a broad bandwidth of 75 to 110 GHz,and has a small signal gain above 21 dB. The noise figure is lower than 5.2 dB throughout the entire W-band (below 3 dB from 89 to 95 GHz) at room temperature. The proposed LNA module exhibits potential for millimeter wave applications due to its high small signal gain,low noise,and low DC power consumption.

A method for loop-circuit stability analysis

A method for loop circuit stability analysis is introduced through investigating its closed-loop admittance and open-loop impedance. This method has wider adaptability and less limitation than the traditional approach which uses open-loop power-wave transfer function. A 6-GHz HBT oscillator is designed to verify this method. The measurement result shows the effeteness of the proposed method while the traditional method fails.

A W-Band single-ended downconversion/upconversion gate mixer in InP HEMT technology

This paper presents an initial design of a single-ended gate mixer in self-developed InP High Electron Mobility Transistor (HEMT) technology and its critical parameters measured from 75 GHz to 110 GHz. This mixer realizes a fair conversion loss between 8 dB to 14 dB in full W-Band both in up and down conversion mode, and a 1-dB input compression points more than 0 dBm with the LO pumped at 89 GHz or 94 GHz. All measurement results above are illustrated and analyzed briefly. In a conclusion, it demonstrates the potentials and possibilities to develop passive mixers in W-Band with this process in more complicated structures.