Amplifier MMIC Research Articles

On-Wafer Noise Measurement at 300 GHz Using UTC-PD as Noise Source

We demonstrate on-wafer noise measurement based on the Y-factor technique at 300 GHz utilizing a uni-traveling-carrier photodiode (UTC-PD) as a noise source. Since the UTC-PD can provide high and scalable noise power for the hot state and has a waveguide output port, easy and reliable measurement is available even at terahertz frequencies, where the loss from the experiment setup is not ignorable. We describe the experimental procedure with the UTC-PD as a noise source and a diode mixer as a noise receiver and present a noise figure measurement for a 300 GHz amplifier MMIC in an on-wafer environment. In addition, we discuss the uncertainty due to using the UTC-PD.

A W-band two-stage cascode amplifier with gain of 25.7 dB

A W-band two-stage amplifier MMIC has been developed using a fully passivated 2 × 20 μm gate-width and 0.15 μm gate-length InP-based high electron mobility transistor (HEMT) technology. The two-stage amplifier has been realized in combination with a coplanar waveguide technique and cascode topology, thus leading to a compact chip-size of 1.85 × 0.932 mm2 and an excellent small-signal gain of 25.7 dB at 106 GHz. Additionally, an inter-digital coupling capacitor blocks low-frequency signal, thereby enhancing the stability of the amplifier. The successful design of the two-stage amplifier MMIC indicates that InP HEMT technology has a great potential for W-band applications.

A Ka-Band 6-W High Power MMIC Amplifier with High Linearity for VSAT Applications

A Ka-band 6-W high power microwave monolithic integrated circuit amplifier for use in a very small aperture terminal system requiring high linearity is designed and fabricated using commercial 0.15-μm GaAs pHEMT technology. This three-stage amplifier, with a chip size of 22.1 mm2 can achieve a saturated output power of 6 W with a 21% power-added efficiency and 15-dB small signal gain over a frequency range of 28.5 GHz to 30.5 GHz. To obtain high linearity, the amplifier employs a class-A bias and demonstrates an output third-order intercept point of greater than 43.5 dBm over the above-mentioned frequency range.

A Ka-Band 6-W High Power MMIC Amplifier with High Linearity for VSAT Applications

A Ka-Band 6-W High Power MMIC Amplifier with High Linearity for VSAT Applications

Development of a Large-Signal-Network-Analyzer Round-Robin Artifact

This article presents the design and measurement results of the contest-winning LSNA round-robin artifact. The proposed two-port device was designed with respect to the objective of complementing an upcoming LSNA international round-robin between measurement facilities. The proposed device consists of three parts, a nonlinear circuit generating the required five harmonics based on a monolithic InGaP HBT MMIC amplifier, an output circuits based on a wideband amplifier and attenuator, which role is to amplify the signal generated by the nonlinear device and isolate the nonlinear device from the output load, and finally, a stabilized dc supply circuit based on voltage regulator chips typically used for instrumentation. To avoid noise interfering with the measurement, EMI considerations were taken into account. The overall device is shielded within a casing composed of three cavities to isolate each circuit. This casing also helps as a heat sink to stabilize the artifact in temperature. The proposed device is validated by measurements. Thanks to a high output signal level at the fundamental and harmonics, a high-value attenuator can be used to efficiently isolate the artifact from the load and still obtain a sufficiently high output signal for accurate measurement with an LSNA.

220-GHz Solid-State Power Amplifier Modules

This paper reports on several solid-state power amplifier (PA) modules operating at frequencies around the 220-GHz propagation window. Included is a single module demonstrating saturated output power ≥60 mW from 205 to 225 GHz and peak output power of 75 mW at 210 GHz using eight-way on-chip power combining. The output power is further increased by using waveguide power combining with WR-4 waveguide. Results include a single two-way combined module achieving >; 100 mW of power from 210 to 225 GHz and four-way combining using two two-way combiners to reach 185 mW of output power at 210 GHz. The amplifier MMICs uses sub-50-nm InP HEMT transistors, coplanar waveguide (CPW) technology, and on-chip electromagnetic transitions to waveguide. Finally, preliminary burn-in and initial room-temperature lifetest data is shown.

Cryogenic 36–45 GHz InP Low-Noise Amplifier MMIC's with Improved Noise Temperature by Eliminating Parasitic Parallel-Plate Modes

This paper describes cryogenic 36–45 GHz InP low-noise amplifier monolithic microwave integrated circuits (MMIC's) with an improved noise temperature by eliminating parasitic parallel-plate resonance modes. These MMIC's are used for a Radio Astronomical receiver, which needs the ultimate super low-noise and wide-band frequency characteristics, such as those in ALMA Band 1. The MMIC chips were designed in the coplanar waveguide (CPW), and mounted to the AlN substrate with a flip-chip assembly, which was promising compared to wire bonding. The flip-chip assemblies, however, are prone to cause the parasitic parallel plate resonance mode (PPM). The relationship between the $S$-parameters and the PPM was investigated by using a 3D-electromagnetic simulation of the simple transmission-line test-chip with the same chip size as that of the actual MMIC. In order to eliminate the PPM, additional bumps were mounted on the simple transmission-line test-chip, and the effect of these bumps was confirmed by the simulation. These results obtained from the simple transmission-line test-chip were applied to an actual MMIC chip assembly. The MMIC assembled with the additional bumps had no abnormality in the measured $S$-parameters, and the PPM had been eliminated up to 65 GHz. Moreover, the stability factor, $K$, became more than 2.4 over 36–45 GHz. This InP low-noise amplifier MMIC exhibited a gain of 15 dB and a noise temperature of 180–240 K at room temperature in the frequency range of 36–45 GHz. When cooled to 28 K, a gain of 17 dB and a noise temperature of 22–35 K were obtained at a power consumption of 4.7 mW over 36–45 GHz. A high-gain amplifier module consisting of two cascaded chips, exhibited a gain of 27–30 dB and a noise temperature of 25–30 K at the ambient temperature of 22 K in the frequency range of 41–45 GHz.

A high-gain high-power amplifier MMIC for V-band applications using 100 nm AlGaN/GaN dual-gate HEMTs

In this paper we present the design and realization of a high-power amplifier in grounded coplanar transmission line technology using AlGaN/GaN dual-gate High electron mobility transistors (HEMTs) with a gate-length of 100 nm to achieve a high gain per stage and high output power. A large-signal model was extracted for the dual-gate HEMT based on the state-space approach. For the fabricated dual-stage amplifier a continuous-wave saturatedoutput power of up to 24.8 dBm (0.84 W/mm) was measured at 63 GHz for 20 V drain bias. A small-signal gain of more than 20 dB was achieved between 56 and 65 GHz.

Efficiency Enhancement of Pico-cell Base Station Power Amplifier MMIC in GaN HFET Technology Using the Doherty Technique

1 Abstract With the growth of smart-phones, the demand for more broadband, data-centric technologies are being driven higher. As mobile operators worldwide plan and deploy 4 generation (4G) networks such as LTE to support the relentless growth in mobile data demand, the need for strategically positioned pico-sized cellular base stations known as ‘pico-cells’ are gaining traction. In addition to having to design a transceiver in a much compact footprint, pico-cells must still face the technical challenges presented by the new 4G systems, such as reduced power consumptions and linear amplification of the signals. The RF power amplifier (PA) that amplifies the output signals of 4G pico-cell systems face challenges to minimize size, achieve high average efficiencies and broader bandwidths while maintaining linearity and operating at higher frequencies. 4G standards as LTE use nonconstant envelope modulation techniques with high peak to average ratios. Power amplifiers implemented in such applications are forced to operate at a backed off region from saturation. Therefore, in order to reduce power consumption, a design of a high efficiency PA that can maintain the efficiency for a wider range of radio frequency signals is required. The primary focus of this thesis is to enhance the efficiency of a compact RF amplifier suitable for a 4G pico-cell base station. For this aim, an integrated two way Doherty amplifier design in a compact 10x11.5mm monolithic microwave integrated circuit using GaN device technology is presented. Using non-linear GaN HFETs models, the design achieves high efficiencies of over 50% at both back-off and peak power regions without compromising on the stringent linearity requirements of 4G LTE standards. This demonstrates a 17% increase in power added efficiency at 6 dB back off from peak power compared to conventional Class AB amplifier performance. Performance optimization techniques to select between high efficiency and high linearity operation are also presented. Overall, this thesis demonstrates the feasibility of an integrated HFET Doherty amplifier for LTE band 7 which entails the frequencies from 2.62-2.69GHz. The realization of the layout and various issues related to the PA design is discussed and attempted to be solved.

Metamorphic HEMT MMICs and Modules Operating Between 300 and 500 GHz

In this paper, we present the development of submillimeter-wave monolithic integrated circuits (S-MMICs) and modules for use in next-generation sensors and high-data-rate wireless communication systems, operating in the 300-500-GHz frequency regime. A four-stage 460-GHz amplifier MMIC and a 440-GHz class-B frequency doubler circuit have been successfully realized using our 35-nm InAlAs/InGaAs-based metamorphic high-electron mobility transistor (mHEMT) technology in combination with grounded coplanar circuit topology (GCPW). Additionally, a 500-GHz amplifier MMIC was fabricated using a more advanced 20-nm mHEMT technology. To package the submillimeter-wave circuits, a set of waveguide-to-microstrip transitions has been fabricated on both 50-μm-thick quartz and GaAs substrates, covering the frequency range between 220 and 500 GHz. The E-plane probes were integrated in a four-stage 20-nm cascode amplifier circuit to realize a full <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</i> -band (220 to 325 GHz) S-MMIC amplifier module with monolithically integrated waveguide transitions.

InGaP/GaAs HBT를 이용한 900 MHz 대역 1 W급 고선형 전력 증폭기 MMIC 설계

본 논문에서는 InGaP/GaAs hetero-junction bipolar transistor(HBT)를 이용하여 900 MHz에서 동작하는 1 W급 선형 전력 증폭기를 설계 및 검증하였다. 온도 변화에 따른 증폭기의 특성 변화를 최소화하기 위해 능동 바이어스 회로를 구성하였다. 전류 붕괴(current collapse)와 열 폭주(thermal runaway)를 방지하기 위하여 ballast 저항을 삽입하여 전력 증폭기의 성능 및 신뢰성을 최적화하였다. 제작된 선형 전력 증폭기는 중심 주파수 900 MHz의 one-tone 신호를 사용하였을 때, 17.6 dB의 전력 이득과 30 dBm의 OP1dB를 가지며, 이때 44.9 %의 PAE를 갖는다. 또한, two-tone 신호를 인가하였을 때, 20 dBm의 평균 출력 전력에서 47.3 dBm의 매우 높은 OIP3를 갖는다. This paper presents a highly linear power amplifier MMIC, having an output power level of about 1 watt, based on InGaP/GaAs hetero-junction bipolar transistor(HBT) technology for the 900 MHz band. The active bias circuit is applied to minimize the effect of temperature variation. Ballast resistors are optimized to prevent a current collapse and a thermal runaway. The fabricated power amplifier exhibited a gain of 17.6 dB, an output P1dB of 30 dBm, and a PAE of 44.9 % at an output P1dB from the one-tone excitation. It also showed a very high OIP3 of 47.3 dBm at an average output power of 20 dBm from the two-tone excitation.

A Ka-band 22 dBm GaN amplifier MMIC

A Ka-band GaN amplifier MMIC has been designed in CPW technology, and fabricated with a domestic GaN epitaxial wafer and process. This is, to the best of our knowledge, the first demonstration of domestic Ka-band GaN amplifier MMICs. The single stage CPW MMIC utilizes an AlGaN/GaN HEMT with a gate-length of 0.25 μm and a gate-width of 2 × 75 μm. Under Vds = 10 V, continuous-wave operating conditions, the amplifier has a 1.5 GHz operating bandwidth. It exhibits a linear gain of 6.3 dB, a maximum output power of 22 dBm and a peak PAE of 9.5% at 26.5 GHz. The output power density of the AlGaN/GaN HEMT in the MMIC reaches 1 W/mm at Ka-band under the condition of Vds = 10 V.

High‐power GaN‐HEMT with low current collapse for millimeter‐wave amplifier

AbstractThere are high expectations for GaN high electron mobility transistors (GaN‐HEMT) to serve as a key device in the production of a high power and high efficiency millimeter‐wave amplifier. Until now, an extremely low three‐terminal pinched‐off‐current of less than 10‐6 A/mm was achieved by applying band engineering. It improved the on‐state breakdown voltage to 50 V and the off‐state breakdown voltage to over 100 V (Makiyama et al., Phys. Status Solidi C 6(S2), S1012 (2009) [1]). However, the output power of a GaN‐HEMT decreases due to current collapse. In particular, the influence of current collapse increases in a GaN‐HEMT with a short gate‐length. In this work, technology was developed to reduce this amount of current collapse. By utilizing thin silicon nitride passivation film that contained many Si‐H bonds, the current collapse was remarkably improved. A 3‐stage common source amplifier MMIC was fabricated that used the current collapse reducing technology. The Pin vs. Pout characteristics were measured at the W‐band. Excellent power characteristics, such as Pout of 1.3 W at 75 GHz at 35 V operation, and a frequency bandwidth of 13 GHz were demonstrated. (© 2011 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

235 GHz Amplifier Using 150 nm InP HBT High Power Density Transistor

In this letter, a four-stage 235 GHz heterojunction bipolar transistor (HBT) amplifier is reported. Each stage uses a single-emitter 0.15 × 3 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> InP HBT with collector current density of 25 mA/μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , maximum frequency of oscillation ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> ) greater than 500 GHz, and a cutoff frequency ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">fT</i> ) of 320 GHz. The MMIC amplifier is realized in inverted microstrip topology. The amplifier demonstrates measured small signal gain of 12.7 dB and output power of 2.6 mW with a power gain of 9.4 dB. This corresponds to transistor output power density of 5.7 mW/μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at 235 GHz. This is the highest HBT transistor output power density published to date at frequencies above 170 GHz, which indicates high power InP HBT power amplifiers should be viable with on-chip power combining.

A 325 GHz InP HBT Differential-Mode Amplifier

An MMIC amplifier operating at the highest reported frequency up to date for indium-phosphide double-heterojunction bipolar (DHBT) transistor technology is presented. The amplifier chain consists of seven unit-cell stages that contain differential-pair common-base HBTs and compact inverted microstrip matching networks. Amplifier operation in differential mode generates a virtual RF ground at a convenient location inside the unit cell. The measurements at 325 GHz show a small signal gain of 25 dB and a maximum output power of -1.5 dBm. An amplifier gain of greater than 20 dB is observed over 60 GHz bandwidth extending from 285 to 345 GHz.

A Novel Wideband Spatial Power Combining Amplifier Based on Turnstile-Junction Waveguide Divider/Combiner

In this paper, we propose a wideband four-way turnstile-junction waveguide divider/combiner in the Ka-band. The proposed divider/combiner has an insertion loss of less than 0.8dB over the frequency range of 28-39.5GHz. A power combiner amplifier using this circuit and four MMIC amplifiers has been demonstrated with 83% combining efficiency at 34.9GHz. The measured results show that the turnstile-junction waveguide divider-combiner is a suitable element for developing a broadband millimeter-wave spatial power combiner amplifier.

A Novel Spatial Power Combining Amplifier Based on Quasi-Yagi Antenna

In this letter, a novel 4-way X-band spatial power divider/combiner has been developed using a modified quasi-Yagi antenna transition. The divider has an insertion loss of less than 0.5dB and a power balance of +/-0.8dB over a bandwidth of 3.5GHz in the X-band. A power combiner amplifier using this circuit and four MMIC amplifiers has been demonstrated with 84% combining efficiency. The obtained results show that the modified quasi-Yagi antenna is a suitable element to develop a broadband spatial power combiner.

A CPW-Based 77 GHz Power Amplifier with Cascode Structure Using a 130 nm In0.88GaP/In0.4AlAs/In0.4GaAs mHEMTs

In this paper, we present a CPW-based 77 GHz 3-stage power amplifier MMIC for automotive radar systems. The power amplifier MMIC has been realized using a 130 nm <TEX>$In_{0.88}$</TEX>GaP/<TEX>$In_{0.4}$</TEX>AlAs/<TEX>$In_{0.4}$</TEX>GaAs metamorphic high-electron mobility transistors(mHEMTs) technology and an output stage with a cascode configuration. This produced a good output power and gain performance at 77 GHz. The fabricated power amplifier MMIC exhibited a small-signal gain of 18 dB, an output power of 17 dBm and 9 % power added efficiency(PAE) at 77 GHz with a total gate width of 800 <TEX>${\mu}m$</TEX> in the output stage. These performances could be useful to low-cost and small-sized components for 77 GHz automotive radar systems.

광대역 위상 배열 안테나의 빔 편이(Beam-Squint) 현상 제거를 위한 4-Bit 시간 지연기 설계

본 논문에서는 전기적으로 크기가 큰 능동 위상 배열 안테나에서 발생하는 빔-편이(beam-squint)현상을 해결할 수 있는 시간 지연기를 설계 및 제작하고, 측정 결과를 고찰한다. 시간 지연기는 4-bit 스위치로 제어되는 마이크로스트립 라인으로 설계되었으며, 시간 지연 구조의 손실을 보상해 주기 위해 송수신 경로에 MMIC 증폭기 모듈을 추가하였다. 시간 지연기의 측정을 통해 지연 상태별 이득 및 위상, P1dB, 수신 잡음 지수 등의 전기적 성능 규격을 만족함을 확인하였다. 또한, 제작된 시간 지연기의 성능 검증을 위해 측정 결과를 광대역 능동위상 배열 안테나에 적용하여 빔 패턴 보정 효과를 확인하였다. X 밴드 대역에서 800 MHz 대역차를 갖는 675.8 mm 크기의 안테나에 대해 빔 편이 현상을 보정해 본 결과 <TEX>${\pm}0.1^{\circ}$</TEX>이던 주파수에 따른 조향각 오차가 <TEX>${\pm}0.1^{\circ}$</TEX> 이내로 줄어드는 효과를 확인하였으며, 향후 광대역 능동 위상 배열 안테나 시스템에 적용 가능성을 확인하였다. In this paper, we have designed TDL(True-time Delay Line) for eliminating beam-squint occurring in active phased array antenna with large electrical size operated in wide bandwidth, and have tested its electrical performance. The proposed TDL device is composed of 4-bit microstrip delay line structure and MMIC amplifier for compensation of the delay-line loss. The measured results of gain and phase versus delay state satisfy the electrical requirements, also P1dB output power and noise figure meet the requirement. To verify the performance of fabricated TDL, we have simulated the beam patterns of wide-band active phased array antenna using the measured results and have certified the beam pattern compensation performance. As a result of simulated beam pattern compensation with respect to the 675.8 mm size antenna which is operated in X-band, 800 MHz bandwidth, we have reduced the beam squint error of <TEX>${\pm}1^{\circ}$</TEX> with <TEX>${\pm}0.1^{\circ}$</TEX>. So this TDL module is able to be applied to active phase array antenna system.

A Cool, Sub-0.2 dB Noise Figure GaN HEMT Power Amplifier With 2-Watt Output Power

This paper reports on a S-, C-band low-noise power amplifier (LNPA) which achieves a sub-0.2 dB noise figure (NF) over a multi-octave band and a saturated output power (Psat) of 2 W at a cool temperature of -30degC . The GaN MMIC is based on a 0.2 mum AlGaN/GaN-SiC HEMT technology with an f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> ~ 75 GHz. At a cool temperature of -30degC and a power bias of 15 V-400 mA, the MMIC achieves 0.25-0.45 dB average NF over a 2-8 GHz band and a linear P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1dB</sub> of 32.8 dBm ( ~ 2 W) with 25% power-added efficiency (PAE). At a medium bias of 12 V-200 mA, the amplifier achieves 0.1-0.2 dB average NF across the same band and a P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1dB</sub> of 32.2 dBm (1.66 W) with 35% PAE. The corresponding saturated output power is greater than 2 W. At a low noise bias of 5 V-200 mA, a remarkable 0.05-0.15 dB average NF is achieved with a P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1dB</sub> > 24 dBm and PAE ~ 33%. These results are believed to be the lowest NF ever reported for a multi-octave fully matched MMIC amplifier capable of > 2 W of output power.