scholarly journals Linearization of broadband microwave amplifier

2014 ◽  
Vol 11 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Aleksandra Djoric ◽  
Natasa Males-Ilic ◽  
Aleksandar Atanaskovic ◽  
Bratislav Milovanovic

The linearization of broadband power amplifier for application in the frequency range 0.9-1.3 GHz is considered in this paper. The amplifier is designed for LDMOSFET characterized by the maximum output power 4W designing the broadband lumped element matching circuits and matching circuits in topologies that combines LC elements and transmission lines. The linearization of the amplifier is carried out by the second harmonics of the fundamental signals injected at the input and output of the amplifier transistor. The effects of linearization are considered for the case of two sinusoidal signals separated in frequency by different intervals up to 80 MHz ranging input power levels to saturation.

Author(s):  
Ehsan Barmala

<span>In this paper, a Doherty power amplifier was designed and simulated at 2.4 GHz central frequency which has high efficiency. A Doherty power amplifier is a way to increase the efficiency in the power amplifiers. OMMIC ED02AH technology and PHEMT transistors, which is made of gallium arsenide, have been used in this simulation. The Doherty power amplifier unique feature is its simple structure which is consisting of two parallel power amplifiers and transmission lines. In order to integrate the circuit, the Doherty power transmission amplifier lines were implemented using an inductor and capacitive components. Also, the Wilkinson power divider is used on the chip input. To improve the efficiency, the auxiliary amplifier dimensions is selected enlarge and the further input power is allocated it by the power divider. A parallel R-C circuit has been used at the input of transistors to improve their stability. Simulation results show that the Doherty power amplifier has 17.2 dB output power gain, 23 dBm maximum output power, and its output power P<sub>1dB</sub> =22.6dBm at compression point -1 dB, also, its maximum efficiency is 55.5%.</span>


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Premmilaah Gunasegaran ◽  
Jagadheswaran Rajendran ◽  
Selvakumar Mariappan ◽  
Yusman Mohd Yusof ◽  
Zulfiqar Ali Abdul Aziz ◽  
...  

Purpose The purpose of this paper is to introduce a new linearization technique known as the passive linearizer technique which does not affect the power added efficiency (PAE) while maintaining a power gain of more than 20 dB for complementary metal oxide semiconductor (CMOS) power amplifier (PA). Design/methodology/approach The linearization mechanism is executed with an aid of a passive linearizer implemented at the gate of the main amplifier to minimize the effect of Cgs capacitance through the generation of opposite phase response at the main amplifier. The inductor-less output matching network presents an almost lossless output matching network which contributes to high gain, PAE and output power. The linearity performance is improved without the penalty of power consumption, power gain and stability. Findings With this topology, the PA delivers more than 20 dB gain for the Bluetooth Low Energy (BLE) Band from 2.4 GHz to 2.5 GHz with a supply headroom of 1.8 V. At the center frequency of 2.45 GHz, the PA exhibits a gain of 23.3 dB with corresponding peak PAE of 40.11% at a maximum output power of 14.3 dBm. At a maximum linear output power of 12.7 dBm, a PAE of 37.3% has been achieved with a peak third order intermodulation product of 28.04 dBm with a power consumption of 50.58 mW. This corresponds to ACLR of – 20 dBc, thus qualifying the PA to operate for BLE operation. Practical implications The proposed technique is able to boost up the efficiency and output power, as well as linearize the PA closer to 1 dB compression point. This reduces the trade-off between linear output power and PAE in CMOS PA design. Originality/value The proposed CMOS PA can be integrated comfortably to a BLE transmitter, allowing it to reduce the transceiver’s overall power consumption.


2014 ◽  
Vol 618 ◽  
pp. 543-547
Author(s):  
Zhou Yu ◽  
Xiang Ning Fan ◽  
Zai Jun Hua ◽  
Chen Xu

A power amplifier (PA) for multi-mode multi-standard transceiver which is implemented in a TSMC 0.18μm process is presented. The proposed PA uses matching compensation, lossy matching network and negative feedback technique to improve bandwidth. To achieve the linearity performance, the two-stage PA operates in Class-A regime. Simulation results show that the power amplifier achieves maximum output power of more than 24dBm in 0.7~2.6GHz. The output P1dBof the PA is larger than 22dBm. The simulated power gain is more than 27dB. The S11 is less than-10dB and the S22 is under-5dB.


2009 ◽  
Vol 1 (2) ◽  
pp. 117-126 ◽  
Author(s):  
Vittorio Camarchia ◽  
Rocco Giofrè ◽  
Iacopo Magrini ◽  
Luca Piazzon ◽  
Alessandro Cidronali ◽  
...  

This paper presents an investigation of a concurrent low-cost dual-band power amplifier (PA) fabricated in SiGe technology, able to simultaneously operate at two frequencies of 2.45 and 3.5-GHz, including an evaluation of its system level performance potentiality. Taking into account the technology novelty and the lack of device characterization and modeling, a hybrid (MIC) approach has been adopted both for a fast prototyping of the PA and for the evaluation of the device potentiality based on an extensive linear and nonlinear characterization. The comparison of PA performance in single-band or concurrent mode operation will be presented. In particular, the measured PA prototype shows an output power of 17.2 and 17-dBm at a 1-dB compression point, at 2.45 and 3.5-GHz, respectively, for CW single-mode operation, with a power added efficiency around 20%. System-level analysis predicts that, when the PA is operated under the 20-MHz Orthogonal Frequency-Division Multiplexing (OFDM) concurrent signals, the maximum output power levels to maintain the Error Vector Magnitude (EVM) within 5% are 11 and 3.5-dBm at 2.45 and 3.5-GHz, respectively. Moreover, new concepts and possible new system architectures for the development of the next generation of the multi-band transceiver front-end will be provided with an extensive system-level evaluation of the amplifier.


Author(s):  
Amine Rachakh ◽  
Larbi El Abdellaoui ◽  
Jamal Zbitou ◽  
Ahmed Errkik ◽  
Abdelali Tajmouati ◽  
...  

Power Amplifiers (PA) are very indispensable components in the design of numerous types of communication transmitters employed in microwave technology. The methodology is exemplified through the design of a 2.45GHz microwave power Amplifier (PA) for the industrial, scientific and medical (ISM) applications using microstrip technology. The main design target is to get a maximum power gain while simultaneously achieving a maximum output power through presenting the optimum impedance which is characteristically carried out per adding a matching circuit between the source and the input of the power amplifier and between the load and the output of the power amplifier. A "T" matching technique is used at the input and the output sides of transistor for assure in band desired that this circuit without reflections and to obtain a maximum power gain. The proposed power amplifier for microwave ISM applications is designed, simulated and optimized by employing Advanced Design System (ADS) software by Agilent. The PA shows good performances in terms of return loss, output power, power gain and stability; the circuit has an input return loss of -38dB and an output return loss of -33.5dB. The 1-dB compression point is 8.69dBm and power gain of the PA is 19.4dBm. The Rollet's Stability measure B1 and the stability factor K of the amplifier is greater than 0 and 1 respectively, which shows that the circuit is unconditionally stable. The total chip size of the PA is 73.5× 36 mm2.


Author(s):  
Seyedehmarzieh Rouhani ◽  
Kasra Rouhi ◽  
Adib Abrishamifar ◽  
Majid Tayarani

This paper presents an approach to power added efficiency (PAE) increase for Quasi-Doherty power amplifier (Q-DPA) design. For this aim, active feedback is utilized instead of a passive quarter wavelength transmission line (TL) usage, which is conventionally used in the DPA schematic. PAE increase can be done by applying an accurate load modulation to the main amplifier (PAmain), especially for technologies in which output impedance of the main power amplifier (Zout,main) considerably varies in both low and high power regions. Because such precise modulation is still based on a modified TL, this approach suffers from the inherent narrowband behavior of that TL. As a consequence, expecting a wideband DPA may not be satisfied in all cases. To deal with this issue, active feedback is used to play a role in reaching PAmain, which is not saturated before, to its maximum efficiency at the highest level of received input power (Pin) in the high power region. Following Zout,main trajectories in power and frequency sweeps simultaneously just by a passive TL are not needed anymore. Still, for the sake of preventing total PAE degradation due to the consummated power by the feedback path’s power amplifier (PAfeedback) should be limited, analytical confinement is provided in this work. A comparison is made between GaAs pHEMT 0.25um MMIC technology-based conventional DPA and the proposed revised approach based-DPA to verify the mentioned approach. The proposed PA shows maximum output power of 33.4 dBm, maximum PAE of 41.6, fractional bandwidth of 11%. The Q-DPA works with a maximum power gain of 24.16.


2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Chang-Hsi Wu ◽  
Hong-Cheng You ◽  
Shun-Zhao Huang

Abstract An architecture of 5.2/5.8-GHz dual-band on-off keying (DBOOK) modulated transmitter is designed in a 0.18-μm CMOS technology. The proposed DBOOK transmitter is used in the biosignal transmission system with high power efficiency and small area. To reduce power consumption and enhance output swing, two pairs of center-tapped transformers are used as both LC tank and source grounding choke for the designed voltage controlled oscillator (VCO). Switching capacitances are used to achieve dual band operations, and a complemented power combiner is used to merge the differential output power of VCO to a single-ended output. Besides, the linearizer circuits are used in the proposed power amplifier with wideband output matching to improve the linearity both at 5.2/5.8-GHz bands. The designed DBOOK transmitter is implemented by dividing it into two chips. One chip implements the dual-band switching VCO and power combiner, and the other chip implements a linear power amplifier including dual-band operation. The first chip drives an output power of 2.2mW with consuming power of 5.13 mW from 1.1 V supply voltage. With the chip size including pad of 0.61 × 0.91 m2, the measured data rate and transmission efficiency attained are 100 Mb/s and 51 pJ/bit, respectively. The second chip, for power enhanced mode, exhibits P1 dB of −9 dBm, IIP3 of 1 dBm, the output power 1 dB compression point of 12.42 dBm, OIP3 of about 21 dBm, maximum output power of 17.02/16.18 dBm, and power added efficiency of 17.13/16.95% for 5.2/ 5.8 GHz. The chip size including pads is 0:693 × 1:084mm2.


2014 ◽  
Vol 6 (5) ◽  
pp. 447-458 ◽  
Author(s):  
Sascha A. Figur ◽  
Friedbert van Raay ◽  
Rüdiger Quay ◽  
Larissa Vietzorreck ◽  
Volker Ziegler

This work presents radio-frequency-microelectromechanical-system (RF-MEMS)-based tunable input- and output-matching networks for a multi-band gallium nitride (GaN) power-amplifier applications. In the first part, circuit designs are shown and characterized for a fixed operation mode of the transistor, i.e. either a maximum-output-power- or a maximum-power-added-efficiency (PAE)-mode, which are finally combined into a multi-mode-matching network (M3N); the M3N allows to tune the operation mode of the transistor independently of its operational frequency. The matching networks are designed to provide optimum matching for the power amplifier at three to six different operating frequencies for maximum-output-power- and maximum-PAE-mode. In the frequency range from 3.5 to 8.5 GHz, return losses of 10 dB and higher were measured and insertion losses of 0.5–1.9 dB were demonstrated for the output-matching networks. Further characterizations were performed to test the dependency on the RF-input power, and no changes were observed up to power levels of 34 dBm when cold-switched.


Author(s):  
Seyedehmarzieh Rouhani ◽  
Kasra Rouhi ◽  
Adib Abrishamifar ◽  
Majid Tayarani

In this work, a premise is applied to the conventional load modulation equation of Doherty power amplifier (DPA) in 0.25 m GaAs pHEMT technology to compensate output impedance of main amplifier ( Z out,main ) variation, even in low power region. Using this modified modulation leads to the DPAs power added efficiency (PAE) increase in comparison by the case in which the load modulation revision is ignored, which is also designed in this paper. Second harmonic rejection networks are also added to both designs to play their roles as to efficiency increase. By doing so, the revised load modulation based DPA has the maximum PAE of 39.6%, maximum output power ( P out ) of 31.61dBm, at 8 GHz. Simulation results of this DPA in higher harmonics indicate the designed DPA has the minimum second and third harmonics power of -51.7 dBm and -80 dBm, respectively. For the sake of linearity evaluation, it is depicted that 1dB-power gain compression has not occurred in the input power (P in ) range in which the proposed DPA works.


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