Amplifier Design Research Articles

Dual-Band, Two-Layer Millimeter-Wave Transceiver for Hybrid MIMO Systems

This article presents a two-layer low-complexity fully connected (FC) RF/analog weighting multi-input–multi-output (MIMO) transceiver comprising an RF weight layer and an analog–baseband weight layer. The transceiver can serve as a small-scale MIMO system by itself and can serve as the building block in a larger hybrid MIMO system. The architecture mitigates the complexity versus spectral-efficiency tradeoffs of existing MIMO architectures and enables MIMO stream/user scalability, superior energy efficiency, and spatial-processing flexibility. A compact, reconfigurable bidirectional circuit architecture is introduced, including a new Cartesian-combining/splitting beamforming receiver/transmitter, dual-band bidirectional beamforming network, dual-band frequency translation chains, and baseband Cartesian beamforming with an improved programmable gain amplifier design. A 28-/37-GHz band, two-layer, eight-element, four-stream hybrid MIMO transceiver prototype is designed in 65-nm CMOS to demonstrate the above features. The prototype achieves accurate beam/null-steering capability, excellent area/power efficiency, and state-of-the-art TX/RX mode performance in two simultaneous bands while demonstrating multi-antenna (up to eight) multi-stream (up to four) over-the-air spatial multiplexing operation using the proposed energy-efficient two-layer hybrid beamforming scheme.

A 17–26.5 GHz 42.5 dBm broadband and highly efficient gallium nitride power amplifier design

A 17–26.5 GHz 42.5 dBm broadband and highly efficient gallium nitride power amplifier design

A novel dual‐band highly efficient power amplifier for 5G applications

This paper presents a novel dual-band highly efficient power amplifier (PA) design for 5G applications. The presented dual-band matching network consists of an impedance tuning network and a dual-band impedance transformer. This structure can not only achieve the precise fundamental and second harmonic control at two 5G bands, but also the excellent dual-band filtering response. Compared with other dual-band PAs, it shows better frequency selectivity and wider bandwidth. For demonstration, a dual-band PA is designed, fabricated, and measured. The measured results display the power added efficiencies of 60% and 47% at 2.5 GHz and 3.5 GHz (bandwidth >150 MHz) under the saturated output power of above 40 dBm, and excellent frequency selectivity with return loss (> 14.7 dB) and stopband rejection (> 25.2 dB).

Low-noise large-bandwidth transimpedance amplifier for measuring scanning tunneling shot noise spectra in cryogenic STM and its applications

Shot noise is a powerful tool to study quantum systems. In this work, a design of transimpedance amplifier (TIA) for a cryogenic scanning tunneling microscope (CryoSTM) is proposed to meet the requirements of the shot noise measurements for quantum systems. In the TIA, the preamplifier is made of the low-noise low-power cryogenic high electron mobility transistors. With the high transimpedance gain of 1 GΩ, the bandwidth of the proposed TIA is larger than 300 kHz. In the CryoSTM, the TIA with the tip-sample component is called as CryoSTM-TIA. The bandwidth of the proposed CryoSTM-TIA is still larger than 300 kHz. Its equivalent input noise current power spectral density is less than 30(fA)2/Hz at 100 kHz. It is detailed, for quantum systems, by using the CryoSTM-TIA, how to measure scanning tunneling current spectra, scanning tunneling differential conductance spectra, and scanning tunneling noise current power spectra, in atomic scale, and then extract their scanning tunneling shot noise spectra. Thus, it is possible to study novel quantum phenomena in various quantum systems by measuring shot noise with the CryoSTM-TIA, such as the Andreev reflection in atomic scale, the Kondo effect in a single molecular magnet, and the existence of Majorana bound states, etc.

Low input-resistance low-power transimpedance amplifier design for biomedical applications

This paper introduces a Transimpedance Amplifier (TIA) design capable of producing an incremental input resistance in the ohmic range, for input signals in the microampere range, such as are encountered in the design of instrumentation for electrochemical ampero-metric sensors, optical-sensing and current-mode circuits. This low input-resistance is achieved using an input stage incorporating negative feedback. In a Cadence simulation of an exemplary design using a 180 nm CMOS process and operating with ± 1.8 V supply rails, the input resistance is 1.05 ohms and the power dissipation is 93.6 µW. The bandwidth, for a gain of 100 dBohm, exceeded 9 MHz. For a 1µA, 1 MHz sinusoidal input signal the Total Harmonic Distortion, with this gain, is less than 1%. The input referred noise current with zero photodiode capacitance is 2.09 pA/√Hz and with a photodiode capacitance of 2pF is 8.52 pA/√Hz. Graphical data is presented to show the effect of a photodiode capacitance varying from 0.5 to 2 pF, when the TIA is used in optical sensing. In summary, the required very low input resistance, at a low input current level (µA) is achieved and furthermore a Table is included comparing the characteristics and a widely used Figure of Merit (FOM) for the proposed TIA and similar published low-power TIAs. It is apparent from the Table that the FOM of the proposed TIA is better than the FOMs of the other TIAs mentioned.

Signal Amplification in Highly Ordered Networks Is Driven by Geometry.

Here, we hypothesize that, in biological systems such as cell surface receptors that relay external signals, clustering leads to substantial improvements in signaling efficiency. Representing cooperative signaling networks as planar graphs and applying Euler’s polyhedron formula, we can show that clustering may result in an up to a 200% boost in signaling amplitude dictated solely by the size and geometry of the network. This is a fundamental relationship that applies to all clustered systems regardless of its components. Nature has figured out a way to maximize the signaling amplitude in receptors that relay weak external signals. In addition, in cell-to-cell interactions, clustering both receptors and ligands may result in maximum efficiency and synchronization. The importance of clustering geometry in signaling efficiency goes beyond biological systems and can inform the design of amplifiers in nonbiological systems.

Effects of the adjacent channels on IP3 and IP5 of RF amplifier

This paper discusses the impact of the adjacent channels on the 1-dB compression point, the IP3 and the IP5 of Radio Frequency (RF) amplifier by n-tone test. By combining the theoretical derivation and software simulation, the model analysis for the third/five order polynomial nonlinear amplifier has been achieved. Moreover, the control variable method is adopted to draw the curves for the input/output signals. The research shows that the 1-dB compression point, the IP3 and the IP5 drop as n increases, and they all have symmetry for a given n. The fifth-order polynomial nonlinear amplifier model is proposed, the research shows that the adjacent channels have a great impact on the 1-dB compression point, the IP3 and the IP5 of the desired channel. This effect must be taken into account in actual RF amplifier designs and wireless communication architectures.

Design of operational transconductance amplifier with Gate-All-Around Nanosheet MOSFET using experimental data from room temperature to 200 °C

In this work, a Gate-All-Around Nanosheet transistor (GAA-NSH) is used to design an operational transconductance amplifier (OTA) operating from room temperature to 200 °C. A simulation model for the transistor was created using Verilog A language including a lookup table (LUT) with current response and capacitance data obtained from measurement of fabricated devices. Two OTA designs were made, for supply voltages (VDD) of 2.1 V and 1.5 V. The first design was analyzed at room temperature (25 °C) with different bias points that defined the transistors efficiency (gm/ID) of the first stage input differential pair and current mirror load. A comparison with other OTA projects using FinFET and Tunnel FET (TFET) devices was performed considering similar gm/ID for all designs. The GAA-NSH design presents a larger voltage gain than the FinFET design (71.8 dB vs. 67.6 dB), while consuming less power (544.5uW vs. 1.41mW) and utilizing smaller devices and an overall smaller area footprint. Improvements are a consequence of the superior gate electrostatic coupling of the GAA-NSH transistors that can be seen through the improved transconductance and output conductance values. Compared with the TFET device, the GAA-NSH presents a tradeoff between Bandwidth and power consumption. Finally, the second OTA designed is analyzed from room temperature to 200 °C, and a decrease of the voltage gain and GBW was observed due to the mobility degradation at high temperature.

L‐band high power solid‐state power amplifier for aerospace usage

This work presents the design, implementation, and experimental results of an L-band solid-state power amplifier (SSPA) developed for the next generation high-power transmitter for the space usage. The microwave frequency nircuit (MFC) is realized by cascading a channel amplifier, a drive power amplifier (PA) and a high PA section. By utilizing the gallium nitride (GaN) HEMTs, the efficiency of the drive PA and high PA are improved to more than 70% over the frequency range from 1.45 to 1.55 GHz, which ensures an overall efficiency of the MFC higher than 66%. Then a high efficiency power-supply based on the phase-array bridge topology is proposed for voltage conversion and output sequence control, which delivers a high efficiency of about 94% at the rated power range. In the 100-MHz operating bandwidth, the SSPA delivers more than 200 W of output power with an associated 3rd order intermodulation product (IM3) and power added efficiency (PAE) better than −18 dBc and 60%, respectively. The gain can be varied from 25 to 56 dB with a minimal step of 0.5 dB through telecommand, whereas the phase can be adjusted within 360° range with a minimal step of 5.6°.

A W-Band Amplifier With a New Wide-Band Interstage Matching Technique Using Self-Resonance of a Microstrip-Coupled Line

A new interstage matching technique is presented for design of a wide-band multi-stage amplifier using commercial 60- <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> m GaN-on-silicon technology in the W-band. The proposed interstage matching network is designed as a two-pole conjugated impedance matching approach for wideband characteristics using low-characteristic impedance transmission lines and an optimized microstrip-coupled line. In particular, the microstrip-coupled line provides strong resonance at the desired frequency, enabling optimal conjugate impedance matching of both edge and intermediate frequencies simultaneously. The implemented W-band three-stage amplifier using the proposed interstage matching technique exhibited a small-signal gain above 14.1 dB from 75 to 103 GHz. Also, the output power between 92-100 GHz was greater than 25 dBm, and the maximum output power at 96 GHz was 25.8 dBm. The W-band amplifier was designed with an area of 2 mm × 1.2 mm.

Design of photonic crystal fiber amplifier based on stimulated Brillouin amplification for orbital angular momentum

A probe made of amino acids is arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues. The sequence of amino acids in a protein is determined by a gene and encoded in the genetic code. This can happen either before the protein is used in the cell, or as part of control mechanisms. In order to transmit and amplify high-purity orbital angular momentum mode, a photonic crystal fiber amplifier based on stimulated Brillouin amplification is proposed and designed in this paper. The transmission properties of the photonic crystal fiber amplifier are systematically analyzed by using the finite element method in the C-band. The results show that this photonic crystal fiber amplifier can support the transmission and amplification of 66 orbital angular momentum modes, and all values of the purity of the orbital angular momentum modes supported by this amplifier are higher than 99.4%. By systematically analyzing the Brillouin gain spectra of orbital angular momentum modes with different topological charges, it is found that they have all high Brillouin gain coefficients (&gt; 7 × 10&lt;sup&gt;–9&lt;/sup&gt; m/W) which are 4–5 orders of magnitude higher than the existing OAM amplifiers with the best performance, thus higher signal gain can be obtained. The comprehensive performance of the proposed photonic crystal fiber amplifier is superior to that of the existing optical fiber amplifiers based on stimulated Brillouin amplification and the optical fiber amplifiers doped with rare-earth ions. This makes the amplification and long-distance transmission of OAM mode stable and accurate and provides a possibility for designing the orbital angular momentum mode laser system.

Collector Series-Resistor to Stabilize a Broadband 400 GHz Common-Base Amplifier

The indium phosphide (InP) 130 nm double-heterojunction bipolar transistor (DHBT) offers milliwatts of output power and high signal amplification in the lower end of the terahertz frequency band when the transistor is used in a common-base configuration. Instrumentation can directly benefit from this technology by enabling the development of novel broadband sources or synthesizers that rely on our ability to amplify the signal over enormous bandwidths. However, the design of high gain and stable amplifiers presents many obstacles and limitations as we increase the bandwidth and the carrier frequency. Here, we show that adding a series resistor at the collector terminal of the common-base transistor prevents instabilities in the terahertz monolithic integrated circuit amplifier and increases its fractional bandwidth. Adopting this technique, we report a state-of-the-art broadband common-base amplifier that exhibits a minimum small-signal gain of 18.9 dB from 325 to 477 GHz. This amplifier presents the highest fractional bandwidth and gain above 300 GHz. Our work demonstrates the feasibility of high-performance amplifiers that address the need of future terahertz electronic systems.

Optimal design of CMOS current mode instrumentation amplifier using bio-inspired method for biomedical applications

Analog integrated circuits for biomedical applications require good performance. This paper presents an instrumentation amplifier (IA) design based on three complementary metal oxide semiconductor (CMOS) conveyors with an active resistor. This circuit offers the possibility to control the gain by voltage and current. We have designed the IA to minimize the parasitic resistance (Rx) with large bandwidth and high common mode rejection ratio (CMRR) using the artificial bee colony algorithm (ABC). The topology is simulated using 0.35µm CMOS technology parameters. The optimization problem is represented by an objective function that will be implemented using MATLAB script. The results were approved by the simulation using the advanced design system (ADS) tool. The simulation results were compared to the characteristics of some other instrumentation amplifiers exsisting in the literature. The circuit has a higher CMRR than other topologies.

A Time-Domain Multi-Tone Distortion Model for Effective Design of High Power Amplifiers

This paper proposes a new time-domain multi-tone distortion (TD-MTD) model suitable for accurately predicting the non-linear behavior of packaged high power radio frequency (RF) transistors over a range of discrete non-uniformly distributed frequencies. This proposed TD-MTD model uses a single expression rather than multiple distinct frequency specific behavioral models to describe the underlying behavior of the high power RF transistor at multiple fundamental frequencies. Furthermore its extraction is carried out using a time-domain representation of the travelling waves that can be acquired using a generic vector load-pull characterization system and without imposing additional requirements. The proposed model is extracted as an artificial neural network (ANN) and is implemented as a Netlist to serve in a harmonic balance simulator based power amplifier design process. The proposed model is validated in two phases. First, its ability to reproduce the large-signal behavior of a high power RF LDMOS transistor was demonstrated in simulation. Then, the TD-MTD model was used to validate the design of a high power two-way asymmetric Doherty power amplifier and the simulated output-power-dependent power efficiency, AM/AM, AM/PM and input return loss characteristics were compared to those obtained in measurement. The excellent agreement between the simulation and measurement results confirms the usefulness of the proposed model despite the simplicity of its extraction routine and measurement data.

Approach for Extreme Learning Machine-Based Microwave Power Device Modeling

The nonlinear representation of active devices plays an important role in microwave circuit design. Whereas, it takes a long time to extract a large amount of large signal data, and the problem of memory resource and CPU occupancy becomes significant. In order to address the problems in traditional large-signal modeling methods, in this paper an X-parameter modeling method for microwave power devices based on extreme learning machine (ELM) is proposed. To demonstrate the effectiveness of this method, a double layer back propagation (BP) neural network model is established. Then, harmonic balance simulations are used to verify the accuracy of these two models. After comparisons, it is proved that the three harmonic errors of double layer BP neural network model are 9.525dBm, 1.309dBm and 14.593dBm, respectively, and the three harmonic errors of ELM model are 0.673 dBm, 0.314 dBm, 3.09 dBm, respectively. Furthermore, the three harmonic modulus errors of double layer BP neural network model are 0.031, 0.002, 7.665e-4, respectively, and the errors of ELM model are 0.005, 0.001, 8.38e-5, respectively. Finally, in order to verify the accuracy of the predicted model in circuit design, the predicted X-parameter is used in the design of power amplifier. Moreover, the errors of the double layer BP neural network prediction model at 2.5 GHz, 5 GHz and 7.5 GHz are 1.142 dBm, 1.436 dBm and 2.294 dBm, respectively. The output power error of the ELM model at 2.5 GHz, 5 GHz and 7.5 GHz are 0.089 dBm, 0.311 dBm and 0.309 dBm, respectively. These experimental results demonstrate that the established ELM model is an efficient and valid approach for modeling GaN high electron mobility transistor types of nonlinear microwave devices.

Dual-Band Power Amplifier Design at 28/38 GHz for 5G New Radio Applications

This paper presents the design of a dual-band power amplifier (PA) featuring similar performance at 28 GHz and 38 GHz. In the new radio (NR) of the fifth generation (5G) communication system, the inter-band carrier aggregation technique is commonly adopted for data rate enhancement. In such configuration, operation at both bands of the 5G frequency range 2 (FR2) spectrum is often necessary. The stacked-FET topology was adopted for mitigation of the gain roll-off with frequency to achieve similar performance at both frequency bands. Implemented in the commercial 0.15-&#x03BC;m gallium arsenide (GaAs) pseudomorphic high electron mobility transistor (pHEMT) technology, the PA delivered a small signal gain of 18.5/18 dB, an output power at saturation (P_sat) of 28.5/28.2 dBm, and a peak power-added efficiency (PAE) of 39%/36% at 28/38 GHz, respectively. The measurement results have demonstrated great potential of the proposed PA for 5G NR applications.

Design of a constant-bandwidth variable-gain amplifier for 5G receivers

Design of a constant-bandwidth variable-gain amplifier for 5G receivers

Analysis of a CS amplifier Based on CNTFET with parasitic elements of interconnection lines

In this paper we present a procedure to study the effects of parasitic elements (capacitances, inductances and resistances) of interconnection lines in integrated circuits where Carbon Nanotubes are embedded. In particular the Drain/Source pads dimensions of CNT are analysed, as well as the interconnection lines between a CNT and an appropriate load are sized. In order to estimate parasitic elements in CNTs embedded integrated circuits, we analyse 50 nm technology. Moreover it is also possible for predictions analysis on 10 nm and 3 nm technology. We apply the proposed procedure to the design of a Common-Source amplifier, using a CNTFET model already proposed by us. The frequency domain simulations, obtained using the ADS simulator, show how the parasitic elements limit the performances of CNTs. In particular we obtain that the -3 dB cutting frequency of the examined amplifier full of parasitic elements increases as technology decreases. Moreover we repeat the proposed simulations using SPICE, obtaining results practically coincident but with the Verilog-A implementation we have mainly a simulation run time much shorter and a software much more concise and clear than schemes using ABM blocks in SPICE.

Development of high data rate optical transmitter in c-band using external modulation technique

This paper presents the development and characterization of high-speed ON-OFF Keying (OOK) Optical Transmitter up to 12 Gbps using External Modulation Technique that comprises Continuous Wave (CW) laser, Mach-Zehnder Modulator (MZM), and ultra-high bandwidth driver amplifier for MZM. The CW laser driver and high bandwidth modulator driver amplifier has been designed and integrated with the modulator which is biased for OOK modulation scheme. This work includes Direct Current (DC), Optical and Radio Frequency (RF) characterization of MZM modulator; selection of suitable bias point for modulator to achieve OOK modulation format, design and development of wideband driver amplifier in microstrip configuration on 25-mil alumina using Hittite device. The biasing circuit for distributed feedback laser is designed as an unmodulated CW optical signal to feed optical modulator. In this work, the assembly and characterization of optical transmitter is also carried out and performance is analyzed in terms of different parameters such as Extinction ratio and Signal-to-Noise Ratio (SNR) etc.

Optimal Design of Low Noise Amplifier Using Novel Mcdm Based Grey Relation Analysis for Wireless Sensing Applications

Optimal Design of Low Noise Amplifier Using Novel Mcdm Based Grey Relation Analysis for Wireless Sensing Applications