A Multiband Reconfigurable Power Amplifier for UMTS Handset Applications

Based on an analog-gain control bias circuit (AGBC), a dynamic and fixed bias-controlled InGaP/GaAs HBT MMIC power amplifier module (PAM) is designed for code-division multiple-access (CDMA) and advanced mobile-phone service (AMPS) handset applications. The proposed AGBC effectively improves the power-added efficiency (PAE) of a power amplifier (PA) over a wide range of output power while satisfying the CDMA/AMPS linearity requirements. The PA gain slope with respect to AGBC mode-control voltage is about 12 dB/V. The measured average current of this AGBC PA is reduced by 64% compared to a standard PA. The AGBC PA exhibits a 28 dB power gain, a 45% PAE, and a -49 dBc adjacent channel power ratio (ACPR) at 28 dBm output power with a fixed mode-control voltage.

A novel reconfigurable multi-band highly efficient power amplifier (PA) is presented that operates in several widely separated frequency bands such as 0.9 to 5 GHz. The newly proposed design scheme for band-switchable matching networks (MNs) makes the network compact, even if they cover various frequency bands. RF-MEMS switches aid in the implementation of the MNs in that they are nearly ideal because the switches have excellent insertion loss and isolation characteristics. According to the proposed scheme, a hexa-band PA was designed and a quad-band PA was fabricated that includes the highest and the lowest frequency bands. The fabricated 1W-class PA achieved high output power and high power added efficiency as expected in the 0.9, 1.5, 2, and 5-GHz bands. The results show that the reconfigurable PA can be extended to "band-free" operation for future mobile terminals

Envelope tracking (ET) prolongs the battery life by modulating the supply of a power amplifier (PA) according to the signal envelope. With this emerging technology, the PA efficiency is greatly improved, whereas the supply modulator (SM) itself needs to provide efficient and accurate envelope tracking for the overall performance of the SM-PA combined system (PA module). The ET technique, meanwhile, has seen limited use in high-power transmission due to the reduced SM efficiency for low output power originating from the linear stage in hybrid structures [1].

A new super-thin power amplifier (PA) module has been developed for W-CDMA mobile handsets. The PA module consists of an InGaP/GaAs HBT MMIC and a 50-Ω output matching circuit on polyimide film, which is the first application of such film as a PA module substrate. The key features of the PA substrate are thinness, low thermal resistance, and low cost. As a result, the PA module is only 6.0 x 6.0 x 0.8 mm3 (0.03cc) and meets the specifications of W-CDMA with a high power-added efficiency (PAE) of 43%, a gain of 27 dB, and an adjacent channel leakage power ratio (ACLR) of -36 dBc at an offset frequency of 5 MHz at a Pout of 26 dBm under a supply voltage of 3.5 V with 3.84 Mcps HPSK modulation.

This paper describes the development of wavegude modules for 120-GHz wireless applications. The MMIC in the modules were fabricated using 0.1-mum-gate InP-HEMTs and coplanar waveguides. The transmitter (Tx) module contains a Tx MMIC and a multiplier MMIC for carrier generation. The Tx MMIC contains a frequency doubler, ASK modulator, and an amplifier. Output power of the Tx module is 0 dBm. The receiver (Rx) module contains a Rx MMIC with a low-noise amplifier and ASK demodulator. For high-power operation of transmitter, we developed a power amplifier (PA) waveguide module that attaches to the Tx module. This PA module contains one-chip PA MMIC, and has 13-dBm output power with associated gain of 10.5 dB at 125 GHz. A back-to-back test of the Tx/Rx modules with and without the PA module have shown it to be fully functional at 10-Gbit/s data rate with BER = 1e-10 at -34.5-dBm and -36.1-dBm input powers for the receiver, respectively

A highly integrated multi-mode multi-band (MMMB) power amplifier module (PAM) using hybrid bulk complementary metal oxide semiconductor (CMOS), gallium arsenide (GaAs) heterojunction bipolar transistor (HBT), and silicon-on-insulator (SOI) technologies for low band (LB, 824–915 MHz) and high band (HB, 1710–1980 MHz) is proposed. The hybrid MMMB PAM integrates a bulk CMOS controller die, a GaAs HBT power amplifier (PA) die and a SOI switch die on a six-layer laminate. To simultaneously obtain both highly efficient and highly linear characteristics over a wide range of input power levels, a parallel dual-chain PA strategy has been adopted to provide vary bias current and gain for low-power mode (LPM) and high-power mode (HPM) operation. Additionally, a broadband two-section low-pass output matching network design based on the suppression of high-order harmonics is proposed for enhanced efficiency and linearity. In order to achieve further miniaturization, a three-dimensional (3D) die stack multi-chip module (MCM) packaging structure, where the presented CMOS controller die is stacked vertically on the GaAs HBT PA die, is implemented. The measurement results show that the fabricated MMMB PAM achieves 26.1–27 dB of power gains and 38–38.4% of PAEs at an output power (Pout) of 28 dBm in the HPM, and 20.4–20.9 dB of power gains and 12.4–13.8% of PAEs at Pout of 17 dBm in the LPM over LB. For HB, power gains of 24.3–26.7 dB while maintaining PAEs of 38.2–39.9% at Pout of 28 dBm, and power gains of 15.9–17.5 dB while maintaining PAEs of 12.3–12.8% at Pout of 17 dBm are realized in the HPM and LPM, respectively. The fabricated PAM covering five frequency bands and operating at two power modes only occupies a 5 × 3.5 mm2 area. To the best of the authors’ knowledge, this work is the first demonstration of a MMMB PAM adopting an ultra-compact 3D vertical stack MCM package with favorable RF performance.

Purpose This paper aims to implement a new high output power fully integrated 23.1 to 27.2 GHz gallium arsenide heterojunction bipolar transistor power amplifier (PA) to meet the stringent linearity requirements of LTE systems. Design/methodology/approach The direct input power dividing technique is used on the chip. Broadband input and output matching techniques are used for broadband Doherty operation. Findings The PA achieves a small-signal gain of 22.8 dB at 25.1 GHz and a saturated output power of 24.3 dBm at 25.1 GHz with a maximum power added efficiency of 31.7%. The PA occupies 1.56 mm2 (including pads) and consumes a maximum current of 79.91 mA from a 9 V supply. Originality/value In this paper, the author proposed a novel direct input dividing technique with broadband matching circuits using a low Q output matching technique, and demonstrated a fully-integrated Doherty PA across frequencies of 23.1∼27.2 GHz for long term evolution-license auxiliary access (LTE-LAA) handset applications.

Effect of voids on thermomechanical cracking in lead-free Sn3Ag0.5Cu interconnections of power modules

A hybrid power amplifier building block and a power amplifier module from 2 GHz to 6 GHz were designed, fabricated and measured. These power amplifiers are all based on AlGaN/GaN HEMT technology. The future applications for these types of power amplifiers are mainly electronic warefare (EW) applications. Novel communication jammers and especially active electronically scanned array EW systems have a high demand for broadband high power amplifiers. Output power levels with a peak value of 90 W at lower frequencies and more than 40 W up to 6 GHz are measured. With these power amplifiers novel EW system approaches can be investigated.

This paper presents a dual power-mode and multi-band power amplifier (PA) for handset applications that improves the efficiency in low-power regions. This PA operates in two modes through path control by a shunt switched capacitor. The proposed control method provides efficient mode control without any efficiency degrading and bandwidth (BW) limiting. The proposed PA, in conjunction with a boosted supply modulator for envelope tracking (ET) operation not only in the high-power mode, but also in the low-power mode, delivers good performance at all average output power levels. The linearity is improved by ET through a proper envelope-shaping method. For demonstrative purposes, the PA and supply modulator are implemented using an InGaP/GaAs heterojunction bipolar transistor and AIGaAs/InGaAs enhancement/depletion-mode pseudomorphic high electron-mobility transistor process and a 0.18- $\mu$ m CMOS process, respectively. The ET PA is tested across the range of 1.7–2.0 GHz using a long-term evolution signal with 16 quadrature amplitude modulation, a 7.5-dB peak-to-average power ratio, and 10-MHz BW. The proposed dual power-mode multi-band ET PA delivers good performance for high- and low-power modes, indicating that the architecture is promising for handset PA applications.

This paper presents a high-power heterojunction bipolar transistor (HBT) power amplifier (PA) module designed for GSM/EDGE applications. The proposed HBT PA employs a differential output stage that delivers high output power at a low supply voltage. A transformer-based output matching network is employed to combine the differential output signals. Through the selection of an appropriate capacitor value at the transformer's center tap, linearity is enhanced across a wide bandwidth without requiring additional second harmonic termination. When assembled with a low-pass filter and an antenna switch, the PA module achieves an output power of 36 dBm and a power-added efficiency (PAE) exceeding 40% in GSM mode. In EDGE mode, it delivers an output power of 28.5 dBm with a PAE exceeding 20%. Additionally, the designed PA module achieves an adjacent channel power ratio of -60 dBc at a 400 kHz offset with an output power of 28.5 dBm.

The design of a reconfigurable continuous Class-F power amplifier (PA) is presented in this paper. A varactor-based output matching network is used to design the reconfigurable continuous Class-F PA. By employing the CREE 10W GaN HEMT device CGH40010F, the design is verified by simulation. The layout simulation results show that more than 50% efficiency is obtained from 0.9GHz to 1.45GHz. In each reconfigurable band with a bandwidth of 200MHz, the power gain is within 10.6±1.0dB.

This paper presents a novel power combining architecture, referred to as distributed efficient power amplifier (DEPA) that mitigates the inherent bandwidth limiting factors in a Doherty power amplifier (DPA), namely, impedance inversion and load modulation, by distributing the conventional auxiliary amplifier of the DPA to multiple auxiliary subamplifiers along a broadband multisection impedance transformer. The proposed technique is demonstrated through the design, implementation, and measurement of a wideband DEPA having 8-dB output power back-off and 72% fractional bandwidth. The experimental results show a Doherty-like efficiency enhancement from 1.8 to 3.8 GHz. For the output power levels of 37.4±1.1 and 45.4±1.1 dBm, corresponding to 8-dB OBO and peak output power, the efficiency levels are between 41%-51% and 42%-62%, respectively. Furthermore, linearized modulated measurements show that the DEPA is linearizable and meets the spectral requirements for modern wireless communication systems.

This paper presents the operation principle of Class-J power amplifiers (PAs) with linear and nonlinear output capacitors (C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">out</sub> s). The efficiency of a Class-J amplifier is enhanced by the nonlinear capacitance because of the harmonic generation from the nonlinear C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">out</sub> , especially the second-harmonic voltage component. This harmonic voltage allows the reduction of the phase difference between the fundamental voltage and current components from 45° to less than 45° while maintaining a half-sinusoidal shape. Therefore, a Class-J amplifier with the nonlinear C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">out</sub> can deliver larger output power and higher efficiency than with a linear C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">out</sub> . As a further optimized structure of the Class-J amplifier, the saturated PA, a recently-reported amplifier in our group, is presented. The phase difference of the proposed PA is zero. Like the Class-J amplifier, the PA uses a nonlinear C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">out</sub> to shape the voltage waveform with a purely resistive fundamental load impedance at the current source, which enhances the output power and efficiency. The PA is favorably compared to the Class-J amplifier in terms of the waveform, load impedance, output power, and efficiency. These operations are described using both the ideal and real models of the transistor in Agilent Advanced Design System. A highly efficient amplifier based on the saturated PA is designed by using a Cree GaN HEMT CGH40010 device at 2.14 GHz. It provides a power-added efficiency of 77.3% at a saturated power of 40.6 dBm (11.5 W).

In this article, in order to enhance the linearity of power amplifier modules (PAM), we have suppressed the harmonics at the output port of a high‐power amplifier (HPA) and cancelled the third‐order intermodulation distortion (third IMD) by a predistortion scheme. The matching network to suppress the harmonics consists of metamaterial like the composite right/left‐handed structure. Both the second and third harmonics are suppressed over 27 dBc. A phase of generated third IMD at the output of the drive amplifier has changed in order to offset the third IMD of HPA. The harmonics of the proposed PAM suppresses over 6 dB more than a single HPA and over 20 dB more than a reference power amplifier. The PAM has 37 dBm of output power and 21.6 dB of power gain. The second harmonic and third IMD are −53 and −42.5 dBc about PAM, respectively. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1497–1500, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27625