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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.

This paper presents a passive planar balanced mixer for 94 GHz applications, based on a commercial 0.1 um GaAs pHEMT technology from WIN Semi. Corp. This mixer shows a single-ended output comversion loss between 9 dB and 11 dB pumped with a 10 dBm LO signal at 94 GHz and a RF input 1dB compression point around 0 dBm. In this design, a Lange plus a 90 degrees electrical length microstrip line is adopted in RF signal path to generate a pair of out of phase RF signals. Meanwhile, this balanced structure provides a LO port to RF port isolation above 20 dB in all W-band. Before final measurements, all bare chips have been thinned to 100 um.

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.

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.

A five-stage W-band low-noise amplifier (LNA) based on the authors' InP/InGaAs double heterojunction bipolar transistors (DHBTs) process is reported. The LNA achieves a peak gain of 33.1 dB and 7.8 dB noise figure at 81GHz. Its output-related 1 dB compression point (P1dB) lies at 5.8 dBm. The high gain and linearity of the LNA is mainly attributed to the performance of the DHBTs exhibiting a high breakdown voltage (BVceo>8.7V), a current gain cutoff frequency (fT) of 167GHz, and a maximum oscillation frequency (fmax) of 265GHz.

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.

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.

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.

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 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 W-band frequency doubler MMIC is designed and fabricated using 1-μm InP DHBT technology. Active balun is employed to transform the single-ended signal into differential output. Push—push configuration loaded with harmonic resonant network is utilized to acquire the second harmonic frequency. A multi-stage differential structure improves the conversion gain and suppresses the fundamental frequency. The MMIC occupies an area of 0.55 × 0.5 mm2 with 18 DHBTs integrated. Measurements show that the output power is above 5.8 dBm with the suppression of fundamental frequency below −16 dBc and the conversion gain above 4.7 dB over 75–80 GHz.

A two-stage MMIC power amplifier has been realized by use of a 1-μm InP double heterojunction bipolar transistor (DHBT). The cascode structure, low-loss matching networks, and low-parasite cell units enhance the power gain. The optimum load impedance is determined from load-pull simulation. A coplanar waveguide transmission line is adopted for its ease of fabrication. The chip size is 1.5 × 1.7 mm2 with the emitter area of 16 × 1 μm × 15 μm in the output stage. Measurements show that small signal gain is more than 20 dB over 75.5–84.5 GHz and the saturated power is 16.9 dBm @ 79 GHz with gain of 15.2 dB. The high power gain makes it very suitable for medium power amplification.