Millimeter-wave Monolithic Integrated Circuit Research Articles

An E band MMIC power amplifier design using 100 nm T‐Gate GaN HEMT on SiC

SummaryThe small signal modeling, design, fabrication, and measurement about monolithic millimeter‐wave integrated circuit (MMIC) using gallium nitride (GaN) power amplifier (PA) on silicon carbide (SiC) working at the E band are proposed in this paper. The two stage PA used customized 4 × 75 μm transistor with 100 nm T gate technology. The extraction and optimization of small signal model are based on single GaN high electron mobility transistor (HEMT)'s measurement. Balanced structure and new method are used by low impedance matching, which can simplify circuits prominently and benefit for die size reduction. Radial stub and LC stub are made the whole circuit in absolute stable status; the in‐series DC block metal–insulator–metal capacitor from the matching circuit ensure the process is within small tolerances. From the 61–66 GHz bandwidth, a peak 10.7 dB small signal gain is obtained from the designed MMIC GaN PA, and also, the maximum output power can reach 29.7 to 30.4 dBm from 61 to 66 GHz, with an associated the peak drain efficiency of 18.8%. The final die size without dicing slot is 3.0 × 1.74 mm2.

Equivalent small-signal model of InP-based HEMTs with accurate radiation effects characterization

In this paper, an effective equivalent modeling technique has been proposed to describe small-signal characteristics of InP-based high electron mobility transistors (HEMTs) after proton radiation, which is composed of an artificial neural network and equivalent-circuit models. Small-signal intrinsic parameters of InP-based HEMTs are extracted from S-parameters before and after 2 MeV proton radiation as modeling objects. The deep learning model of a generative adversarial network has been explored to expand the measured finite data samples. Four feedforward neural networks are incorporated to equivalent-circuit topology to form the equivalent model, which are trained to accurately predict the radiation-induced variations of Cgs, Cgd, Rds, and gm, respectively. The prediction accuracy of the developed equivalent model has been well verified in terms of the broad-band S-parameters under radiation fluence of 1 × 1014 and 5 × 1013 H+/cm2. This equivalent modeling method with characterization of radiation damage effects could provide significant guidance for the aerospace monolithic millimeter-wave integrated circuit design.

A Compact 281–319 GHz Low-Power Downconverter MMIC for Superheterodyne Communication Receivers

This article presents a fully integrated first downconversion stage for a superheterodyne receiver for high data rate communication at 300 GHz. It comprises a frequency multiplier-by-three, an active dual-gate downconverter, and an LNA. The chip was fabricated in a 35-nm InGaAs-based metamorphic high-electron-mobility transistor technology. The downconverter was designed to be used for different local oscillator (LO) frequencies between 70 and 80 GHz and intermediate frequency (IF) frequencies from 65 to 95 GHz, to create multiple channels for real-time full-duplex communication in the terahertz region. It achieves a conversion gain of 14 dB without IF amplification and 3-dB bandwidth of 25 GHz in the desired upper sideband from 288 to 313 GHz and an estimated NF of 6.6 dB. Without the LNA, the conversion gain of the circuit is $-$ 10 dB and it shows 3-dB bandwidth of 38 GHz in a frequency range from 281 to 319 GHz. Finally, the millimeter-wave monolithic integrated circuit (MMIC) will be compared in detail to a similar state-of-the-art downconverter using a resistive mixer and a necessary additional LO buffer stage in the same technology targeting the identical application. While exhibiting a better conversion gain and bandwidth and occupying only 40% of chip area, the presented downconverter consumes 70% less dc power than the MMIC with a resistive mixer.

A superheterodyne 300 GHz wireless link for ultra-fast terahertz communication systems

A superheterodyne transmission scheme is adopted and analyzed in a 300 GHz wireless point-to-point link. This was realized using two different intermediate frequency (IF) systems. The first uses fast digital synthesis which provides an IF signal centered around a carrier frequency of 10 GHz. The second involves the usage of commercially available mixers, which work as direct up- and down-converters, to generate the IF input and output. The radio frequency components are based on millimeterwave monolithic integrated circuits at a center frequency of 300 GHz. Transmission experiments over distances up to 10 m are carried out. Data rates of up to 60 Gbps using the first IF option and up to 24 Gbps using the second IF option are achieved. Modulation formats up to 32QAM are successfully transmitted. The linearity of this link and of its components is analyzed in detail. Two local oscillators (LOs), a photonics-based source and a commercially available electronic source are employed and compared. This work validates the concept of superheterodyne architecture for integration in a beyond-5G network, supplying important guidelines that have to be taken into account in the design steps of a future wireless system.

An mm-Wave CMOS I–Q Subharmonic Resistive Mixer for Wideband Zero-IF Receivers

In this letter, we propose a novel wideband subharmonically pumped fully differential I–Q resistive mixer architecture, which eliminates the necessity for on-chip dc-blocking capacitors to integrate IF amplifiers. The proposed differential subharmonic mixer topology is verified by presenting a CMOS millimeter-wave monolithic integrated circuit (MMIC), which includes the mixer and two on-chip differential IF amplifiers at the mixer’s I- and Q-channels. The 3-dB IF frequency bandwidth is measured from 0.01 to 5 GHz with a peak conversion gain (CG) of −2 dB and an image rejection ratio (IRR) of more than 25 dB over the IF frequency range. The proposed mixer covers the input signal (RF) frequency from 170 to 185 GHz. The mixer has also been tested with an on-chip voltage-controlled oscillator (VCO) and shows −4.7-dB CG with a 3-dB IF bandwidth from 0.01 to 4.5 GHz.

Broadband 300-GHz Power Amplifier MMICs in InGaAs mHEMT Technology

In this article, we report on compact solid-state power amplifier (SSPA) millimeter-wave monolithic integrated circuits (MMICs) covering the 280–330-GHz frequency range. The technology used is a 35-nm gate-length InGaAs metamorphic high-electron-mobility transistor (mHEMT) technology. Two power amplifier MMICs are reported, based on a compact unit amplifier cell, which is parallelized two times using two different Wilkinson power combiners. The Wilkinson combiners are designed using elevated coplanar waveguide and air-bridge thin-film transmission lines in order to implement low-loss 70-Ω lines in the back-end-of-line of this InGaAs mHEMT technology. The five-stage SSPA MMICs achieve a measured small-signal gain around 20 dB over the 280–335-GHz frequency band. State-of-the-art output power performance is reported, achieving at least 13 dBm over the 286–310-GHz frequency band, with a peak output power of 13.7 dBm (23.4 mW) at 300 GHz. The PA MMICs are designed for a reduced chip width while maximizing the total gate width of 512 μm in the output stage, using a compact topology based on cascode and common-source devices, improving the output power per required chip width significantly.

20-nm In0.8Ga0.2As MOSHEMT MMIC Technology on Silicon

High-gain millimeter-wave monolithic integrated circuit (MMIC) amplifiers have been developed, based on a planar metamorphic 20-nm gate length InGaAs metal–oxide–semiconductor high-electron-mobility transistor (MOSHEMT) technology on Si. Therefore, an Al2 O 3/Hf O 2 layer stack was deposited as a gate dielectric directly on top of an In0.8Ga0.2As channel by atomic layer deposition. The III–V heterostructure was epitaxial grown on a GaAs wafer and subsequently direct wafer bonded to a Si substrate, leading to a high-quality III–V channel formation on Si. The gate layout was optimized for millimeter-wave and submillimeter-wave integrated circuit applications using T-gates and wet chemical recess etching to minimize the parasitic gate capacitances. For a $2 \times 10 \,\,\mu \text{m}$ gate width transistor, a transit frequency $\text{f}_{\textrm {T}}$ of 200 GHz and a record maximum oscillation frequency $\text{f}_{\textrm {max}}$ of 640 GHz were extrapolated. A realized three-stage cascode amplifier circuit demonstrated a maximum gain of 21 dB at 278 GHz and a small-signal gain of more than 17 dB between 222 and 284 GHz. The total chip size of the millimeter-wave amplifier MMIC was only $0.5\,\,\times \,\,1.2$ mm2. To verify the RF performance of the III–V MOSHEMT on Si technology, all devices and circuits have been reproduced using an InGaAs MOSHEMT on GaAs technology, which has been processed simultaneously within the same wafer batch and achieved almost identical results.

Optimum Wideband High Gain Analog Beamforming Network for 5G Applications

A broadband high-gain millimeter-wave (mmWave) array beamforming network (BFN) design, analysis, and implementation based on the Rotman lens antenna array feeding are presented. The BFN is intended for operation in the (26-40) GHz frequency band for a wide range of potential applications in the fifth generation (5G). The system is made on Rogers substrate, RO6010, to provide compatibility with standard planar low-cost processing techniques for millimeter-wave monolithic integrated circuit (MMIC). The measured results show the system capability of 80° beam scanning for different angles at -39.7°, -26.5°, -13.3°, 0°, +13.3°, +26.5°, and +39.5° at 28 GHz. With these features in addition to being compact size, low profile, and lightweight, this BFN is suitable for various millimeter-wave and 5G applications such as the advanced multi-in multi-out (MIMO) systems, remote sensing, and automotive radar.

A Compact <italic>Ka</italic>-Band Integrated Doherty Amplifier With Reconfigurable Input Network

In this paper, we present the design of an ultracompact monolithic millimeter-wave integrated circuit Doherty power amplifier (DPA) using a novel reconfigurable input network at Ka -band. The proposed input network is formed by a compact broadside coupler and two additional field-effect transistors. By reconfiguring the relative phase offset between the main and auxiliary amplifiers, the DPA can be postoptimized to achieve high efficiency and maximal power gain flatness. More importantly, the DPA can be tuned for the highest performance at different frequencies. To verify the concept, a DPA is fabricated in a 0.15- $\mu \text{m}$ enhancement mode Gallium Arsenide (GaAs) process and exhibits a measured output power of 26.5 dBm and gain of 11.8 dB at 28 GHz. The peak power-added efficiency (PAE) is 42%, and the PAE at 6-dB output power backoff (PBO) is 31%, respectively. With reconfigurable capability, the DPA can maintain high performance over a 3-GHz frequency band from 26.5 to 29.5 GHz. To the best of the authors’ knowledge, the proposed DPA achieves among the highest backoff PAE over a wide bandwidth at Ka -band.

E-Band 4-Bit Phase Shifter using SP4T Flip Chip Switches

Abstract A 4-bit millimeter-wave switched delay line phase shifter is presented. The phase shifter is designed using commercially available SP4T flip-chip millimeter-wave monolithic integrated circuits (MMICs) attached to an alumina substrate. The module operates in the E-Band from 82 – 84 GHz and has an average insertion loss of 20 dB. The size of the module is 10 mm × 7.5 mm. This paper presents a cost effective 4-bit E-Band phase shifter.

Manufacturable Low-Cost Flip-Chip Mounting Technology for 300–500-GHz Assemblies

We developed a chip mounting technology suitable for low-cost assemblies in the 300–500-GHz frequency range, compatible with standard chip and submount fabrication techniques. The waveguide and transition designs are compatible with indium phosphide heterobipolar transistor millimeter-wave monolithic integrated circuit chip architecture. Increased conductor shielding in different multilayer thin-film waveguide topologies is applied to suppress radiative losses, enabling low-loss interconnects up to 500-GHz bandwidth. Standard flip-chip align-and-place equipment is used to assemble the chips onto submounts. Losses are evaluated by banded ${S}$ -parameter measurements between 10 MHz and 500 GHz. For an optimized stripline-to-stripline transition, an insertion loss of less than 1 dB was measured at 500 GHz.

Efficient EM Simulation of GCPW Structures Applied to a 200-GHz mHEMT Power Amplifier MMIC

The behaviour of grounded coplanar waveguide (GCPW) structures in the upper millimeter-wave range is analyzed by using full-wave electromagnetic (EM) simulations. A methodological approach to develop reliable and time-efficient simulations is proposed by investigating the impact of different simplifications in the EM modelling and simulation conditions. After experimental validation with measurements on test structures, this approach has been used to model the most critical passive structures involved in the layout of a state-of-the-art 200-GHz power amplifier based on metamorphic high electron mobility transistors (mHEMTs). This millimeter-wave monolithic integrated circuit (MMIC) has demonstrated a measured output power of 8.7 dBm for an input power of 0 dBm at 200 GHz. The measured output power density and power-added efficiency (PAE) are 46.3 mW/mm and 4.5 %, respectively. The peak measured small-signal gain is 12.7 dB (obtained at 196 GHz). A good agreement has been obtained between measurements and simulation results.

High‐gain wide‐bandwidth low noise amplifier multi‐chip waveguide module at V‐band

ABSTRACTA low‐noise, high‐gain, wide‐bandwidth multi‐chip module has been developed at V‐Band with WR‐15 waveguide interface using commercial‐off‐the‐shelf (COTS) Low Noise Amplifier (LNA) Monolithic Millimeter‐wave Integrated Circuits (MMICs). Waveguide module design ensures there is minimal impact on noise figure and gain of MMICs due to integration on the module and it is rugged to sustain impact of fabrication/assembly tolerances. The realized six‐stage LNA module has small‐signal gain of 32–35 dB and room temperature noise figure ranging from 2.2 to 4.4 dB in 50–60 GHz frequency band. The module design has been simulated using 3D electromagnetic solver ‐ High Frequency Structure Simulator (HFSS). © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:380–384, 2017

S-parameter characterization and lumped-element modelling of millimeter-wave single-drift impact-ionization avalanche transit-time diode

Five silicon (Si) p++–n−–n++ samples were grown at various doping concentrations (1.0 × 1017–2.2 × 1017 cm−3) in an n− layer by using the reduced-pressure CVD technique. By using these samples, 30 × 2 µm2 single-drift (SD) impact-ionization avalanche transit-time (IMPATT) diodes were processed with Si-based monolithic millimeter-wave integrated circuit (SIMMWIC) technology.,) The samples within a small process window exhibited a large negative differential resistance at approximately the avalanche frequency, as confirmed by small-signal S-parameter characterization. A model based on depletion width was given to explain the conditions for the appearance of the negative differential IMPATT resistance, which is the basis of millimeter-wave amplifier and oscillator applications. Furthermore, a measurement-based small-signal lumped-element model was established to describe the IMPATT functionality from the circuit component aspect. This lumped-element model shows a negative differential resistance within a well-defined range in the given element parameters, which can explain the experimental observations.

Multi-Gigabit Millimeter-Wave Wireless Communication in Realistic Transmission Environments

With the growing interest in millimeter-wave (mmW) communication links, especially for multi-gigabit backhaul applications, detailed studies on the performance limits in terms of achievable transmission distance and data rate, but also, and perhaps even more important, thorough investigations on the influence of different weather conditions gain in importance. In this paper we present a millimeter-wave monolithic integrated circuit (MMIC)-based transmit and receive front-end and ultra-broadband wireless data transmission experiments utilizing a 240 GHz carrier frequency in a long-range outdoor scenario as well as measurements inside a climatic wind tunnel. Data rates up to 64 Gb/s and various complex modulation formats are employed. While in the outdoor transmission, the link is tested in terms of maximum achievable transmission distance and data rate as well as alignment accuracy, in the climatic wind tunnel the influence of rain and fog in the transmission path is investigated in a defined and controlled environment.

A 50 to 146 GHz Power Amplifier Based on Magnetic Transformers and Distributed Gain Cells

A monolithic millimeter-wave integrated circuit power amplifier covering the entire V-, W- and F-band is presented. The amplifier applies magnetic distributed transformers in combination with traveling wave gain cells to achieve a $-3~{\rm dB}$ bandwidth that spans from 50 to 146 GHz, 12 dB gain and a maximum measured output power of 15 dBm. With a relative bandwidth of 98.3% the PA achieves the highest bandwidth reported for power amplifiers operating at around 100 GHz to date.

A Novel 1$\times$4 Coupler for Compact and High-Gain Power Amplifier MMICs Around 250 GHz

For application in radar and communication systems operating in the frequency range around 250 GHz, a power amplifier (PA) millimeter-wave monolithic integrated circuit (MMIC) has been developed. The amplifier makes use of a novel coupler approach allowing for in-phase and equal-magnitude distribution of an incoming signal to four parallel output ports. This is possible due to a subtle use of grounded coplanar waveguide and air-bridge microstrip transmission lines, providing different propagation constants. With a size of quarter-wavelength, the coupler is very compact and is the key to the presented PA topology. The amplifier exploits the virtual open occurring due to the identical signals for transistor biasing and matching. The amplifier topology is applied to develop an amplifier MMIC. When biased for maximum gain, it shows a 17-GHz 3-dB bandwidth around its center frequency at 248 GHz with a maximum gain of 32.8 dB. When biased for maximum output power, it provides an output power of 10 and 8.5 dBm at 250 and 270 GHz, respectively. At 250 GHz, it demonstrates a state-of-the-art power density of 125 mW/mm. Due to the amplifier topology, the MMIC is very compact $({\hbox{1.25}}\times {\hbox{0.75}}~{\hbox{mm}}^{2})$ .

Polymer Multichip Module Process Using 3-D Printing Technologies for D-Band Applications

A novel all-in-polymer multichip module (MCM-P) process is presented for applications at D-band (110–170 GHz). The unique manufacturing approach is an additive 3-D printing approach based on a gradual photo-induced polymerization in the $z$ -direction with metallized interconnection layers in between. The package design integrates a broadband waveguide transition nearly covering the entire D-band. Different transmission-line types for chip interconnections were characterized up to 170 GHz. In prior research, a millimeter-wave monolithic integrated circuit (MMIC) amplifier using a 50-nm metamorphic high electron-mobility transistor technology was designed. In this study, the co-design with the package is presented. The amplifier MMIC was bond-wire free embedded in an MCM-P test structure and contacted with coplanar measurement probes. A gain of more than 20 dB within 100–170 GHz was measured. Based on those results, an amplifier MCM-P with integrated waveguide transitions of size 6 mm $\times$ 4.5 mm was developed. The MCM-P was surface mounted on a printed circuit board and flipped into a waveguide test fixture. A gain of more than 20 dB remained from 125 to 155 GHz with an input and output matching better than 10 dB.

Millimeter-Wave Surface Mount Technology for 3-D Printed Polymer Multichip Modules

Board level integration of novel all-in-polymer 3-D printed multichip modules process (MCM-P) at millimeter-wave frequencies is presented. The modules were manufactured using additive 3-D printing technologies based on mask-defined gradual photopolymerization in the z -direction. A lead frame structure was introduced resulting in a quad-flat no-lead footprint of 0.5-mm pitch. The front-side of the modules integrated transmission lines of the centered stripline type for interconnecting embedded millimeter-wave monolithic integrated circuits up to D -band (110-170 GHz). Broadband surface mount transitions from the MCM-P front-side interconnection layers to a high-frequency printed circuit board (PCB) were investigated. Dual channel test modules were characterized in back-to-back configuration, representing the integration needs of millimeter-wave multiple-input-multiple-output systems. The de-embedded PCB transition exhibited an insertion loss of less than 2 dB up to 75 GHz and less than 1 dB up to 60 GHz with a return loss better than 10 dB.

A 200 GHz Medium Power Amplifier MMIC in Cascode Metamorphic HEMT Technology

A 200 GHz power amplifier is presented. The millimeter-wave monolithic integrated circuit (MMIC) has been realized in a 35 nm InAlAs/InGaAs cascode metamorphic high electron mobility transistor (MHEMT) process in grounded coplanar waveguide technology (GCPW). The amplifier demonstrates an output power of 14 mW with 11.4 dB compressed power gain at 200 GHz. This represents an increase in output power in comparison to previous reported MHEMT-based MMIC amplifiers. The small-signal gain demonstrates a peak value of 20 dB and is above 15.9 dB from 185 to 215 GHz.