A 0.25-μm gate-length pseudomorphic HFET with 32-mW output powerat 94 GHz

The 94-GHz power performance of a 0.25×75-μm doped-channel pseudomorphic heterostructure FET (HFET) is reported. A maximum output power of 32 mW, corresponding to a power density of 0.43 W/mm, was obtained with 15% power-added efficiency and 3.0 dB gain     

Indium gallium arsenide microwave power transistors

Depletion-mode InGaAs microwave power MISFETs with 1-μm gate lengths and up to 1-mm gate widths have been fabricated using an ion-implanted process. The devices employed a plasma-deposited silicon/silicon dioxide gate insulator. The DC current-voltage (I -V) characteristics and RF power performance at 9.7 GHz are presented. The output power, power-added efficiency, and power gain as a function of input power are reported. An output power of 1.07 W at 9.7 GHz with a corresponding power gain and power-added efficiency of 4.3 dB and 38%, respectively, was obtained. The large-gate-width devices provided over twice the previously reported output power for InGaAs MISFETs at X-band. In addition, the first report of RF output stability of InGaAs MISFETs over 24 h period is also presented. An output power stability within 1.2% over 24 h of continuous operation was achieved. In addition, a drain current drift of 4% over 10⁴ s was obtained     

InGaAs field-effect transistors with submicron gates forK-band applications

Depletion mode InGaAs microwave power MISFETs with 0.7 μm gate lengths and 0.2 mm gate widths have been fabricated using an epitaxial process. The devices employed a plasma deposited silicon dioxide gate insulator. The RF power performance at 18 GHz, 20 GHz, and 23 GHz is presented. An output power density of 1.04 W/mm with a corresponding power gain and power-added efficiency of 3.7 dB and 40%, respectively, was obtained at 18 GHz. This is the highest output power density obtained for an InGaAs based transistor on InP at K-band. Record output power densities for an InGaAs MISFET were also demonstrated to the stable within 3% over 17 hours of continuous operation at 18 GHz     

High-power V-band AlInAs/GaInAs on InP HEMTs

The DC and RF performance of δ-doped channel AlInAs/GaInAs on InP power high-electron-mobility transistors (HEMTs) are reported. A 450-μm-wide device with a gate-length of 0.22 μm has achieved an output power of 150 mW (at the 1-dB gain compression point) with power-added efficiency of 20% at 57 GHz. The device has a saturated output power of 200 mW with power-added efficiency of 17%. This is the highest output power measured from a single InP-based HEMT at this frequency, and demonstrates the feasibility of these HEMTs for high-power applications in addition to low-noise applications at V -band     

A double-recessed Al0.24GaAs/In0.16GaAspseudomorphic HEMT for Ka- and 𝒬-band power applications

A double-recessed 0.2-μm-gate-length pseudomorphic HEMT (PHEMT) has been demonstrated with 500 mW of output power (833 mW/mm of gate periphery), 6-dB gain, and 35% power-added efficiency (PAE) at 32 GHz. At 44 GHz, the device exhibited 494 mW of output power (823 mW/mm), 4.3-dB gain, and 30% PAE. This level of performance is attributed to excellent MBE material, optimized epitaxial layer design, and the use of individual source vias and of double recess with tight channel dimensions. Excellent 3-in-wafer uniformity was also observed: DC yield was greater than 95% and the interquartile range for all DC parameters was less than 20% of the median value (most are significantly lower)     

An InP MISFET with a power density of 1.8 W/mm at 30 GHz

The millimeter-wave power performance of a 75-μm×0.3-μm InP MISFET with SiO₂ insulator is presented. The combination of high intrinsic transconductance (120 mS/mm), current density (1 A/mm), and gate-source and gate-drain breakdown voltages (35 V) led to a record power density of 1.8 W/mm and 20% power-added efficiency at 30 GHz. This power density is the highest ever reported for any three-terminal device at this frequency     

High power-added efficiency MMIC amplifier for 2.4 GHz wirelesscommunications

This work describes the design and the measured performance of a high-efficiency monolithic microwave integrated circuit (MMIC) amplifier for wireless communications in the 2.4 GHz band. The monolithic technology employed in the circuit integration is based on standard 0.5-μm-gate-length MESFET. The design procedure is based on load-cycle graphic optimization of the transistor performance. On-wafer experimental characterization shows output power up to 24 dBm and excellent results of power-added efficiency up to 79% with 19.5 dBm output power at low drain bias voltage. The amplifier performance achieved and the circuit size, which is 1 mm², are suitable for use in the transmitter chains of wireless communication systems in the 2.4 GHz band     

Submicron-gate InP power MISFET's with improved output powerdensity at 18 and 20 GHz

The microwave characteristics at 18 and 20 GHz of submicron-gate indium phosphide (InP) metal-insulator-semiconductor field-effect transistors (MISFETs) for high output power density applications are presented. InP power MISFETs were fabricated with 0.7 μm gate lengths, 0.2 mm gate widths, and drain-source spacings of 2, 3 and 5 μm. The output power density was investigated as a function of drain-source spacing. The best output power density and gain were obtained for drain-source spacings of 3 μm. At 18 GHz output power densities of 1.59 W/mm with a gain of 3.47 dB and a power-added efficiency of 20.0% were obtained for a drain-source spacing of 3 μm. At 20 GHz output power densities of 1.20 W/mm with a gain of 3.17 dB and a power-added efficiency of 13.6% were obtained for a drain-source spacing of 3 μm     

InP depletion-mode microwave MISFET's

Depletion-mode aligned-gate InP MISFET's with gate lengths of 1.5-1 µm have given output power of 1.26-W/mm gate width and power-added efficiencies of up to 40 percent at 4 GHz. At 12 GHz, 0.75-W/mm gate width with 22-percent power-added efficiency was obtained. At 18 GHz, a power output of 331 mW (0.59 W/mm) with 3.1 dB of gain and 15.7-percent power-added efficiency was measured. An output power of 245 mW (0.44 W/mm) with 3-dB gain and 10.7-percent efficiency was obtained at 20 GHz.     

AlGaAs/InGaAs/GaAs quantum-well power MISFET at millimeter-wavefrequencies

An AlGaAs/InGaAs/GaAs quantum-well MISFET developed for power operation at millimeter-wave frequencies is described. The InGaAs channel is heavily doped to increase the sheet carrier density, resulting in a maximum current density of 700 mA/mm with a transconductance of 480 mS/mm. The 0.25-μm×50-μm device delivers a power density of 0.76 W/mm with 3.6-dB gain and 19% power-added efficiency at 60 GHz. At 5.2 dB gain, the power density is 0.55 W/mm. A similar device built on an undoped InGaAs channel had much poorer power performance and no speed advantage     

60-GHz power performance of ion-implantedInxGa(1-x/)AsGaAs MESFETs

State-of-the-art 60-GHz power performance is reported for ion-implanted InGaAs/GaAs MESFETs with 0.25×200-μm gate length. At output power of 100 mW, a power-added efficiency of 15% and associated gain of 4.2 dB were obtained and a saturated output power of 121 mW was achieved for the same device. These results are comparable to the best reported millimeter-wave power performance of InGaAs/GaAs pseudomorphic HEMTs     

Self-aligned-gate GaInAs microwave MISFET's

A self-aligned-gate GaInAs metal-insulator-semiconductor FET (MISFET) fabrication process that minimizes gate overlap capacitance and offers the potential of achieving submicrometer gate lengths is described. GaInAs MISFETs (1-µm gate length) fabricated with this process have given 0.49-W/mm gate width and corresponding power-added efficiencies of 48 and 39 percent at 4 and 8 GHz, respectively, at a drain voltage of 5.5. V. A small-signal gain of 3.2 dB was obtained at 15 GHz. The estimated carrier velocity was 1.7 × 10⁷cm/s. More recent devices have carrier velocities of 2.5 × 10⁷cm/s and are expected to have improved microwave performance.     

Very high power-added efficiency and low-noise 0.15-μmgate-length pseudomorphic HEMTs

0.15-μm-gate-length double-heterojunction pseudomorphic high electron mobility transistors (HEMTs) for which excellent millimeter-wave power and noise performance were achieved simultaneously are reported. The 50-μm-wide HEMTs yielded record maximum power-added efficiencies of 51, 41, and 23% at 35, 60, and 94 GHz, respectively. Maximum output powers of 139 mW at 60 GHz and 57 mW at 94 GHz were also measured for 150-μm-gate-width devices. Finally, minimum noise figures as low as 0.55 and 1.8 dB were measured at 18 and 60 GHz respectively. This is the best power and noise performance yet reported for passivated transistors at millimeter-wave frequencies     

V-band high-efficiency high-power AlInAs/GaInAs/InP HEMT's

The authors report on the state-of-the-art power performance of InP-based HEMTs (high electron mobility transistors) at 59 GHz. Using a 448-μm-wide HEMT with a gate length of 0.15 μm, an output power of 155 mW with a 4.9-dB gain and a power-added efficiency of 30.1% were obtained. By power-combining two of these HEMTs, an output power of 288 mW with 3.6-dB gain and a power-added efficiency of 20.4% were achieved. This is the highest output power reported with such a high efficiency for InP-based HEMTs, and is comparable to the best results reported for AlGaAs/InGaAs on GaAs pseudomorphic HEMTs at this frequency     

W-band InP HEMT MMICs using finite-ground coplanar waveguide(FGCPW) design

In this paper, we report on the development of W-band monolithic microwave integrated circuit (MMIC) power amplifiers using 0.1-μm AlInAs/GaInAs/InP high electron mobility transistor (HEMT) technology and finite-ground coplanar waveguide (FGCPW) designs. In the device modeling, the Angelov nonlinear HEMT model was employed to predict the large signal performance of the device, and the results were validated by using state-of-the-art vector load-pull measurements. A two-stage single-ended W-band FGCPW MMIC using a 150-μm-wide HEMT as the driver and a 250-μm-wide HEMT for the output stage was designed, fabricated, and tested. The MMIC amplifier demonstrates a maximum output power of 18.6 dBm with 18.2% power-added efficiency and 10.6 dB associated gain at 94 GHz. This result is the best output power to date reported from an InP-based MMIC using FGCPW design at this frequency     

Millimeter-wave power operation of an AlGaAs/InGaAs/GaAs quantumwell MISFET

The authors have developed state-of-the-art millimeter-wave power transistors using quantum-well MISFETs. MISFETs with both undoped InGaAs wells and doped InGaAs wells have been built. The f_t of the MISFETs with doped well was higher than that of MISFETs with undoped wells, indicating that the device speed does not degrade when the charge transport layer is doped. The power performance of the MISFETs with doped wells was far superior. The best device delivered a power density of 1.0 W/mm with 3.2-dB gain and 27% power-added efficiency at 60 GHz     

GaAs/AlGaAs heterojunction MISFET's having 1-W/mm power density at 18.5 GHz

The previously reported GaAs/AlGaAs heterojunction MISFET with an undoped AlGaAs layer as an insulator has been further optimized for power operation at upper Ku band. A 300-µm gate-width device generated 320 mW of output power with 33-percent efficiency at 18.5 GHz. The corresponding power density exceeds 1 W/mm. When optimized for efficiency, the device has achieved a power added efficiency of 43 percent at 19 GHz.     

GaAs power MESFET with 41-percent power-added efficiency at 35 GHz

A GaAs power MESFET has been optimized for Ka-Band operation. The device has an n⁺ ledge channel structure with a 0.25-μm gate on MBE-grown material. An output power density of 0.71 W/mm was achieved with 5.2-dB gain and 34% power-added efficiency. When tuned for maximum efficiency, a power-added efficiency of 41% was obtained with a power density of 0.61 W/mm and a gain of 5.6 dB     

High-power-density GaAs MISFETs with a low-temperature-grownepitaxial layer as the insulator

A GaAs layer grown by molecular beam epitaxy at 200°C is used as the gate insulator for GaAs MISFETs. The gate reverse breakdown and forward turn-on voltages, are improved substantially by using the high-resistivity GaAs layer between the gate metal and the conducting channel. It is shown that a reverse bias of 42 V or forward bias of 9,3 V is needed to reach a gate current of 1 mA/mm of gate width. A MISFET having a gate of 1.5×600 μm delivers an output power of 940 mW (1.57-W/mm power density) with 4.4-dB gain and 27.3% power added efficiency at 1.1 GHz. This is the highest power density reported for GaAs-based FETs     

AlInAs/GaInAs on InP HEMTs for low power supply voltage operation of high power-added efficiency microwave amplifiers

High power-added efficiency microwave power amplifier results are reported for AlInAs/GaInAs on InP HEMTs operated at relatively low power supply voltages (2.5-3 V). C-band power amplifiers are reported with power-added efficiencies as high as 67%, and output powers between 200 and 300 mW. This excellent performance at low power supply voltages is attributed to the high gain and low access resistances of the devices, which leads to a high drain efficiency despite the low power supply voltage.<>