A fully matched dual stage CMOS power amplifier with integrated passive linearizer attaining 23 db gain, 40% PAE and 28 DBM OIP3

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.

A planner Doherty power amplifier with harmonic suppression with open and short ended stubs

This paper presents a new Doherty power amplifier (DPA) with harmonics suppression. A Wilkinson power divider (WPD) with open-ended and short-ended stubs is designed to suppress unwanted signals. To design the power divider in the circuit of the DPA, even and odd mode analyses are utilized. The proposed design operates at range of 1.2–1.6 GHz. The linearity of the suggested DPA is increased about 6 dBm, in comparison with the main amplifier. The designed Doherty amplifier has a power added efficiency (PAE), drain efficiency (DE) and Gain about 60, 61% and 19 dB, respectively. The designed WPD suppresses 2nd up to 14th harmonics with more than 20 dB suppression level, which is useful for suppressing unwanted harmonics in DPA design. ATF-34143 transistors (pHEMT technology) are used for this DPA amplifier design. The main amplifier has class-F topology and class-F inverse topology is used for auxiliary amplifier.

A two-stage power amplifier design for ultra-wideband applications

In this paper, a two-stage 0.18 μm CMOS power amplifier (PA) for ultra-wideband (UWB) 3 to 5 GHz based on common source inductive degeneration with an auxiliary amplifier is proposed. In this proposal, an auxiliary amplifier is used to place the 2nd harmonic in the core amplified in order to make up for the gain progression phenomena at the main amplifier output node. Simulation results show a power gain of 16 dB with a gain flatness of 0.4 dB and an input 1 dB compression of about -5 dBm from 3 to 5 GHz using a 1.8 V power supply consuming 25 mW. Power added efficiency (PAE) of around 47% at 4 GHz with 50 Ω load impedance was also observed.

1178 J, 527 nm near diffraction limited laser based on a complete closed-loop adaptive optics controlled off-axis multi-pass amplification laser system

A 1178 J near diffraction limited 527 nm laser is realized in a complete closed-loop adaptive optics (AO) controlled off-axis multi-pass amplification laser system. Generated from a fiber laser and amplified by the pre-amplifier and the main amplifier, a 1053 nm laser beam with the energy of 1900 J is obtained and converted into a 527 nm laser beam by a KDP crystal with 62% conversion efficiency, 1178 J and beam quality of 7.93 times the diffraction limit (DL). By using a complete closed-loop AO configuration, the static and dynamic wavefront distortions of the laser system are measured and compensated. After correction, the diameter of the circle enclosing 80% energy is improved remarkably from 7.93DL to 1.29DL. The focal spot is highly concentrated and the 1178 J, 527 nm near diffraction limited laser is achieved.

A 5-nV/√Hz Chopper Negative-R Stabilization Preamplifier for Audio Applications

This paper presents a low-noise and low-power audio preamplifier. The proposed low-noise preamplifier employs a delay-time chopper stabilization (CHS) technique and a negative-R circuit, both in the auxiliary amplifier to cancel the non-idealities of the main amplifier. The proposed technique makes it possible to mitigate the preamplifier 1/f noise and thermal noise and improve its linearity. The low-noise preamplifier is implemented in 65 nm complementary metal-oxide semiconductor (CMOS) technology. The supply voltage is 1.2 V, while the power consumption is 159 µW, and the core area is 192 µm2. The proposed circuit of the preamplifier was fabricated and measured. From the measurement results over a signal bandwidth of 20 kHz, it achieves a signal-to-noise ratio (SNR) of 80 dB, an equivalent-input referred noise of 5 nV/√Hz and a noise efficiency factor (NEF) of 1.9 within the frequency range from 1 Hz to 20 kHz.

Femtosecond Red and Near-Infrared Lasers Due to Cascaded-Raman-Assisted Four-Wave Mixing in a Nonlinear Yb-Doped Fiber Amplifier

We demonstrated a straightforward approach to generate red and near-infrared laser emissions by a Raman-assisted four wave mixing (FWM) process in a nonlinear Yb-doped fiber amplifier, delivering 342 fs pulses of 241 nJ at 864 nm, 834 fs pulses of 21 nJ at 751 nm, and 1.9 ps pulses of 3.8 μJ at 1030 nm. A pair of gratings was employed as the pre-compressor to promote the intensity of the fundamental wave in the main amplifier. Multiple wavelengths from 751 to 1273 nm resulted due to cascaded-Raman-assisted FWM. The pre-compression also underlay the achievement of 25.1, 701, and 2000 kW peak power for the red (751 nm), near-infrared (864 nm), and fundamental (1030 nm) components respectively, which restrained the gain narrowing effect during the amplification. It finally led to shorter pulse duration under increased power.

An Analog-Front ROIC with On-Chip Non-Uniformity Compensation for Diode-Based Infrared Image Sensors

This paper proposes a CMOS front-end readout-integrated circuit (ROIC) with on-chip non-uniformity compensation technique for a diode-based uncooled infrared image sensor. Two techniques are adopted to achieve on-chip non-uniformity compensation: a reference dummy metal line is introduced to alleviate the dominant non-uniformity with IR-drop presented in large pixel array, and a current splitting architecture-based variable current source for diode bias is proposed to compensate other residual non-uniformity. A differential integrator is chosen as the main amplifier of readout circuit for its superior noise performance. For low power design, a pulse-powered row buffer is designed in this work. The proposed ROIC for 384 × 288 diode-based detector array is fabricated with a 0.35- μ m CMOS process. It occupies an area of 4.4 mm × 15 mm, and the power consumption is 180 mW. The measured result shows that with the proposed on-chip non-uniformity compensation, the output voltage variation is greatly reduced from 2.5 V to 60 mV.

Performance demonstration of the PEnELOPE main amplifier HEPA I using broadband nanosecond pulses

We report on the energetic and beam quality performance of the second to the last main amplifier section HEPA I of the PEnELOPE laser project. A polarization coupled double-12-pass scheme to verify the full amplification capacity of the last two amplifiers HEPA I and II was used. The small signal gain for a narrow-band continuous wave laser was 900 and 527 for a broadband nanosecond pulse, demonstrating 12.6 J of output pulse energy. Those pulses, being spectrally wide enough to support equivalent 150 fs long ultrashort pulses, are shown with an excellent spatial beam quality. A first active correction of the wavefront using a deformable mirror resulted in a Strehl ratio of 76% in the single-12-pass configuration for HEPA I.