Millimeter-wave Amplifier Research Articles

Custom chipset and compact module design for a 75–110 GHz laboratory signal source

We report on the development and characterization of a compact, full-waveguide bandwidth (WR-10) signal source for general-purpose testing of mm-wave components. The monolithic microwave integrated circuit (MMIC) based multichip module is designed for compactness and ease-of-use, especially in size-constrained test sets such as a wafer probe station. It takes as input a cm-wave continuous-wave (CW) reference and provides a factor of three frequency multiplication as well as amplification, output power adjustment, and in situ output power monitoring. It utilizes a number of custom MMIC chips such as a Schottky-diode limiter and a broadband mm-wave detector, both designed explicitly for this module, as well as custom millimeter-wave multipliers and amplifiers reported in previous papers.

Constant Loss Contours of Matching Networks for Millimeter-Wave LNA Design

This letter presents a new tool of constant loss contours for matching network loss evaluation. With a certain source impedance, the contours illustrate the matching loss while an arbitrary load impedance is matched to the source impedance. The contours are also applied to millimeter-wave circuit design to help designers consider the circuit topologies, transistor sizes, and layout effects. A millimeter-wave CMOS low-noise amplifier has been optimized by using the constant loss contours. The measured results show a low noise figure of 4.85 dB and a gain of 21.0 dB at 79.5 GHz while only consuming 8 mW from a 1.0 V supply.

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.

An 88.5–110 GHz CMOS Low-Noise Amplifier for Millimeter-Wave Imaging Applications

This letter presents a wideband millimeter-wave low-noise amplifier (LNA) in a 65 nm CMOS technology. The amplifier adopts five-stage cascode topology with L-type input matching and T-type output matching. By distributing the peak gains of first four stages at two frequency points, the LNA achieves a flat gain response over a wide bandwidth. The measurement results show that the amplifier features a peak gain of 16.7 dB at 104 GHz, a minimum NF of 7.2 dB, and a 3 dB bandwidth of 21.5 GHz. The LNA consumes 48.6 mW and occupies a compact core area of 0.05 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

Full Band Millimeter-Wave Power-Combining Amplifier Using a Lossy Power-Combining Network

This paper presents a millimeter-wave broadband power-combining amplifier using a novel lossy waveguide-based power combiner. The lossy combiner has a performance of broadband low-loss combining symmetrically and has properties of good match and high isolation at and between ports, because lossy planar lines are embedded in the lossy combiner and even-mode excitations are weakened. The measured results show that the lossy combiners has a loss of about 0.14 dB and achieves reflection and isolation of about—15 dB in 26.5–40 GHz. And then, using the lossy combiner, a compact lossy waveguide-based four-way-combining network is fabricated. The lossy network has a measured loss of about 0.25 dB and achieves good improvements of match and isolation in the full Ka-band. The improvements can enhance stability of amplifying units when the lossy combining network used in multi-way power-combining amplifier. Using the lossy combining network, a solid-state power-combining amplifier is developed, and corresponding experimental results show that output power is more than 30 dBm and combining efficiency is more than 80 % in the full Ka-band.

9.99 mW 4.8 dB NF 57-81 GHz CMOS low-noise amplifier for 60 GHz WPAN system and 77 GHz automobile radar system

A low-power and wideband two-stage millimeter-wave low-noise amplifier (LNA) for 60 GHz wireless personal area network system and 77 GHz automotive radar system using standard 90 nm CMOS technology is reported. T-match technique is used to achieve simultaneously wideband input and output impedance matching, wideband power gain (S21), and wideband noise figure (NF). The LNA consumes 9.99 mW, achieving S11 better than −−10 dB for frequencies of 57.6–81.8 GHz, and S12 better than −−29.1 dB for frequencies of 10–110 GHz. Additionally, high and flat S21 of 11.2 ± 1.5 dB is achieved for frequencies of 57.9–80.4 GHz, which means the corresponding 3-dB bandwidth is 22.5 GHz. Furthermore, the LNA achieves minimum NF of 4.8 dB at 76 GHz and NF of 6.2 ± 1.4 dB for frequencies of 76–84 GHz, one of the best NF results ever reported for a CMOS or SiGe BiCMOS LNA with operation frequency around 77 GHz. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:594–600, 2015

A broad-band V-band power amplifier using a reduced access-resistance transistor layout in 65-nm CMOS

To improve millimeter-wave amplifier performance, we propose a transistor layout that reduces the gate access resistance. The proposed layout trades overlap capacitance for reduced gate access resistance, as shown by transistor parameter extraction. The proposed transistor layout improves the maximum available power gain by 1.5 dB at 67 GHz. The extrapolated maximum frequency of oscillation (f max) also increases by 23 % from 91.3 to 112.5 GHz. Using the improved transistor layout, we design a V-band power amplifier that has enhanced performance. The power amplifier fabricated using the proposed transistor achieves 15.1 dB of small-signal gain, 16.5 GHz of 3-dB bandwidth, and an output power of 7.8 dBm at 61.5 GHz. Compared to an amplifier using conventional layout, the small-signal gain is improved by 3.7 dB and the output power is increased by 3 dBm at 61.5 GHz.

Voltage lowering and gain control techniques for a single-supply-driven 0.7 V amplifier

A CMOS amplifier architecture is presented with a voltage lowering technique so that it can be driven from a single 0.7 V bias supply. The topology does not need scaled gate voltages (or additional bias circuits) and uses branching of its bias path to reduce power requirement. A three-stage cascaded structure is adopted for high gain with the output common-drain block realizing a gain control mechanism. The technique achieves 6 dB gain regulation (with a control voltage) at the expense of small additional power (1.27 mW). A K-band architecture is simulated with a 90-nm CMOS process to verify the proposed mechanisms. The low-power (7.37 mW) unregulated front-end achieves 27 dB gain with a noise figure range of 2.99–3.06 dB within the 20.5–22.2 GHz bandwidth. Port reflection loss figures ( and ) are analysed to be −8 dB and −11 dB. The circuit has an area requirement of 0.62 mm2 and performs better in terms of power supply requirement and potential packaging cost when compared with simulated results of published millimetre-wave amplifiers.

Design and Optimization of a Milli-Meter Wave Amplifier Using Nano-Scale CMOS Devices

Design and Optimization of a Milli-Meter Wave Amplifier Using Nano-Scale CMOS Devices

First Reliability Demonstration of Sub-200-nm AlN/GaN-on-Silicon Double-Heterostructure HEMTs for Ka-Band Applications

In this paper, an emerging double-heterostructure high-electron mobility transistor based on AlN/GaN/AlGaN grown on silicon substrate is presented, which enables a unique simultaneous achievement of high breakdown voltage and high frequency performance. This configuration system allowed state-of-the-art GaN-on-silicon dc, RF output power, and noise performances at 40 GHz, paving the way for high-performance millimeter-wave (mmW) cost-effective amplifiers. Preliminary reliability assessment has been performed on this new class of RF devices, showing promising mmW GaN-on-Si device stability for the first time.

Analysis and Design of a Voltage–Current Transformer Feedback Neutralization Network With an Arbitrarily Chosen Coupling-Factor

One of the transformer neutralization conditions derived theoretically in previous publications is to make the coupling factor, k, of the transformer as close to one as possible, which is not easy to realize over millimeter-wave frequency range. To seek a method for neutralizing the transistor gate-drain capacitance to cope with the imperfect reverse isolation with the transformer coupling factor not necessarily being close to one, a voltage-current transformer feedback network is adopted in this paper. A phase noninverting transformer is added between gate and drain nodes of a transistor to form a voltage-current feedback. The neutralization condition of this network is derived. The effect of this network on the gain is predicted theoretically. The noise behavior of this network is also analyzed and compared theoretically with other transformer feedback structures reported in the millimeter-wave amplifier design. A Q-band three-stage amplifier using this network is designed to demonstrate the feasibility of this network. This amplifier is implemented in 90-nm low-power bulk CMOS technology. Measurement results show that this amplifier has the peak gain of 18.3 dB at 46 GHz and the reverse isolation better than 40 dB over the operation frequency range while consuming 20 mW at a supply voltage of 1.2 V, which verifies the unilateralization effect by using this network.

Development of Millimeter-wave High Power GaN Amplifier Technology

Development of Millimeter-wave High Power GaN Amplifier Technology

Millileter-Wave Power-Combining Amplifier Using A Broadband Waveguide Combiner

A Millimeter-wave power-combining amplifier based on the multi-way rectangular-waveguide power-dividing/combining circuit has been presented and investigated. The equivalent-circuit approach has been used to analyze the passive power-dividing/combining circuits. An eight-device amplifier is designed and measured to validate the power-dividing/combining mechanism using this technique. Both the measured 10-dB return loss bandwidth and the 2-dB insertion loss bandwidth of the passive system are more than 10 GHz. The measured maximum small-signal gain of the millimeter-wave eight-device power amplifier is 22.5 dB at 26.8 GHz with a 3-dB bandwidth of more than 6 GHz, while the input and output return loss of the proposed eight-device power amplifier is around −10 dB from 26 GHz to 36 GHz. The measured maximum output power at 1-dB compression from the power amplifier is 28 dBm at 29.5 GHz.

First Demonstration of High-Power GaN-on-Silicon Transistors at 40 GHz

In this letter, high-output-power-density GaN-based high-electron-mobility transistors grown on a 100-mm silicon substrate is demonstrated for the first time at 40 GHz. The use of an optimized double heterostructure based on ultrathin barrier AlN/GaN allows both high current density and low leakage current, resulting in high-frequency performance (fmax close to 200 GHz). Furthermore, the control of the trapping effects on these highly scaled devices enabled to set a first benchmark at 40 GHz with 2.5 W/mm at VDS = 15 V, mainly limited by RF losses and thermal issues. These results show that an AlN/GaN/AlGaN heterostructure grown on silicon substrate is a viable technology for cost-effective high-power millimeter-wave amplifiers fully compatible with standard Si-based devices.

Stable High-Power Second-Harmonic Coaxial-Waveguide Gyrotron Traveling-Wave-Tube Amplifier

The gyrotron traveling-wave-tube (gyro-TWT) amplifier is a high-power broad-band millimeter-wave amplifier. Its operation at a high harmonic number is of practical importance because the required magnetic field strength can be reduced by a factor of the harmonic number. Although hollow circular waveguides have typically been used as the interaction structure in harmonic gyro-TWTs, spurious oscillations limit their performance. This study investigates the possibility of using coaxial waveguides as the interaction structure in a second-harmonic gyro-TWT. Stability is achieved by applying distributed losses on the outer and inner walls. Simulation results indicate that the distributed losses on the inner wall can suppress specific oscillating modes without deteriorating the performance of the amplifying mode. Under stable operating conditions, simulations indicate that the second-harmonic coaxial gyro-TWT generates a peak power of 293 kW in the Ka-band with 21% efficiency, a saturated gain of 42 dB, and a bandwidth of 1.31 GHz (≈ 4.1%) for a 70-kV 20-A electron beam with an α = 1.0 and an axial velocity spread of 5%.

Analysis and Design of a 60 GHz Wideband Voltage-Voltage Transformer Feedback LNA

To cope with the problem of instability and imperfect reverse isolation, a millimeter-wave voltage-voltage transformer feedback low noise amplifier has been analyzed, designed, and measured in CMOS 65 nm technology. Analytical formulae are derived for describing the stability, gain, and noise in this circuit topology. An analogy with the classic concept of Masons's invariant is used to illustrate how the transformer feedback provides the required reverse isolation in the LNA. Based on the developed theoretical analysis, the circuit is implemented as a fully integrated 60 GHz two-stage differential low noise amplifier in 65 nm CMOS technology. A flat gain of 10 dB is achieved over the entire 6 GHz bandwidth. The measured noise figure is 3.8 dB.

New Performance Indicators of Metal–Oxide–Semiconductor Field-Effect Transistors for High-Frequency Power-Conscious Design

With the progress of complementary metal–oxide–semiconductor (CMOS) process technology, it is possible to apply CMOS devices to millimeter-wave amplifier design. However, the power consumption of the system becomes higher in proportion to its target frequency. Moreover, CMOS devices are biased at a point where the device achieves the highest gain and consumes much power. In order to reduce the power consumption without any compromise, we introduce two types of indicator. One works towards achieving the highest gain with the lowest power consumption. The other works towards achieving the highest linearity with consideration of the power consumption. In this work, we have shown the effectiveness of those indicators by applying measured data of the fabricated metal–oxide–semiconductor field-effect transistors (MOSFETs) to cascade common-source amplifiers.

Study of Nonlinear Oscillation Behavior of a Gyrotron Traveling-Wave Tube

The gyrotron traveling wave tube (gyro-TWT) is a high-power, broadband, millimeter-wave amplifier. This study employed a nonlinear self-consistent code to analyze nonlinear oscillation behavior of a gyro-TWT. There are three operating regimes in the gyro-TWT, including amplification, nonlinear oscillation and mode competition regimes. Based on theory of nonlinear oscillation, the amplification and nonlinear oscillation modes are the stable modes and compete with each other in the mode competition regime. An oscillator plane of the gyro-TWT is elucidated in the paper. This work shows that the amplification mode transits to the nonlinear oscillation mode where the input power exceeds the critical power and the beam current is above the start-oscillation current on the free-running operation. Moreover, the peak gain for the nonlinear oscillation mode is enhanced as the frequency of the input sign approaches the oscillation frequency on free-running operation.

Enhanced performance of a 60-GHz power amplifier by using slow-wave transmission lines in 40 nm CMOS technology

This paper shows the contribution of slow-wave coplanar waveguides on the performance of power amplifiers operating at millimeter-wave frequencies in CMOS-integrated technologies. These transmission lines present a quality factor Q two to three times higher than that of the conventional microstrip lines at the same characteristic impedance. To demonstrate the contribution of the slow-wave transmission lines on integrated millimeter-wave amplifiers performance, two Class-A single-stage power amplifiers (PA) operating at 60 GHz were designed in standard 40 nm CMOS technology. One of the power amplifiers incorporates only the microstrip lines, whereas slow-wave coplanar transmission lines are considered in the other one. Both amplifiers are biased in Class-A operation, drawing, respectively, 22 and 23 mA from 1.2 V supply. Compared to the power amplifier using conventional microstrip transmission lines, the one implemented with slow-wave transmission lines shows improved performances in terms of gain (5.6 dB against 3.3 dB), 1 dB output compression point (OCP1dB: 7 dBm against 5 dBm), saturated output power (Psat: &gt;10 and 8 dBm, respectively), power-added efficiency (PAE: 16% instead of 6%), and die area without pads (Sdie: 0.059 mm2 against 0.069 mm2).

Design and evaluation of a pulsed-jet chirped-pulse millimeter-wave spectrometer for the 70–102 GHz region

Chirped-pulse millimeter-wave (CPmmW) spectroscopy is the first broadband (multi-GHz in each shot) Fourier-transform technique for high-resolution survey spectroscopy in the millimeter-wave region. The design is based on chirped-pulse Fourier-transform microwave (CP-FTMW) spectroscopy [G. G. Brown, B. C. Dian, K. O. Douglass, S. M. Geyer, S. T. Shipman, and B. H. Pate, Rev. Sci. Instrum. 79, 053103 (2008)], which is described for frequencies up to 20 GHz. We have built an instrument that covers the 70-102 GHz frequency region and can acquire up to 12 GHz of spectrum in a single shot. Challenges to using chirped-pulse Fourier-transform spectroscopy in the millimeter-wave region include lower achievable sample polarization, shorter Doppler dephasing times, and problems with signal phase stability. However, these challenges have been partially overcome and preliminary tests indicate a significant advantage over existing millimeter-wave spectrometers in the time required to record survey spectra. Further improvement to the sensitivity is expected as more powerful broadband millimeter-wave amplifiers become affordable. The ability to acquire broadband Fourier-transform millimeter-wave spectra enables rapid measurement of survey spectra at sufficiently high resolution to measure diagnostically important electronic properties such as electric and magnetic dipole moments and hyperfine coupling constants. It should also yield accurate relative line strengths across a broadband region. Several example spectra are presented to demonstrate initial applications of the spectrometer.