Yu Lin

Bio: Yu Lin is an academic researcher from Delft University of Technology. The author has contributed to research in topics: Direct-coupled amplifier & Amplifier. The author has an hindex of 4, co-authored 4 publications receiving 296 citations.

Adaptive Multi-Band Multi-Mode Power Amplifier Using Integrated Varactor-Based Tunable Matching Networks

Abstract: This paper presents a multi-band multi-mode class-AB power amplifier, which utilizes continuously tunable input and output matching networks integrated in a low-loss silicon-on-glass technology. The tunable matching networks make use of very high Q varactor diodes (Q>100 @ 2 GHz) in a low distortion anti-series configuration to achieve the desired source and load impedance tunability. A QUBIC4G (SiGe, ft=50 GHz) high voltage breakdown transistor (VCBO=14 V, VCEO>3.6 V) is used as active device. The realized adaptive amplifier provides 13 dB gain, 27-28 dBm output power at the 900, 1800, 1900 and 2100 MHz bands. For the communication bands above 1 GHz optimum load adaptation is facilitated resulting in efficiencies between 30%-55% over a 10 dB output power control range. The total chip area (including matching networks) of the amplifier is 8 mm2

Low-distortion, low-loss varactor-based adaptive matching networks, implemented in a silicon-on-glass technology

Abstract: A low-loss, low-distortion continuously tunable matching network, is demonstrated at 2 GHz in a silicon-on-glass varactor IC technology. The tuner uses an optimized varactor configuration to minimize distortion, and exhibits less than 0.5 dB loss and IM3 250:1 to 1:1.

A Monolithic Low-Distortion Low-Loss Silicon-on-Glass Varactor-Tuned Filter With Optimized Biasing

Abstract: A low-distortion varactor-tuned bandpass filter is demonstrated on a high-Q silicon-on-glass technology. The dc bias network is optimized to achieve high linearity, the center frequency of the filter tunes from 2.4 to 3.5 GHz, and the measured loss of the filter is 2-3 dB at 2 GHz, with a stopband rejection of 25 dB. The measured IIP3 of the filter was +46 dBm

Improved hybrid SiGe HBT class-AB power amplifier efficiency using varactor-based tunable matching networks

Abstract: This paper presents a 1.8GHz prototype class-AB power amplifier using a QUBIC4G (SiGe, f/sub t/ = 40GHz) handset device with adaptive in- and output matching networks. The realized amplifier provides: 13dB gain, 28 dBm output power, with an efficiency greater than 33-51% over a 10dB output power control range.

Adaptive Multi-Band Multi-Mode Power Amplifier Using Integrated Varactor-Based Tunable Matching Networks

Abstract: This paper presents a multi-band multi-mode class-AB power amplifier, which utilizes continuously tunable input and output matching networks integrated in a low-loss silicon-on-glass technology. The tunable matching networks make use of very high Q varactor diodes (Q>100 @ 2 GHz) in a low distortion anti-series configuration to achieve the desired source and load impedance tunability. A QUBIC4G (SiGe, ft=50 GHz) high voltage breakdown transistor (VCBO=14 V, VCEO>3.6 V) is used as active device. The realized adaptive amplifier provides 13 dB gain, 27-28 dBm output power at the 900, 1800, 1900 and 2100 MHz bands. For the communication bands above 1 GHz optimum load adaptation is facilitated resulting in efficiencies between 30%-55% over a 10 dB output power control range. The total chip area (including matching networks) of the amplifier is 8 mm2

Design of Varactor-Based Tunable Matching Networks for Dynamic Load Modulation of High Power Amplifiers

Abstract: In this paper, the design of varactor-based tunable matching networks for dynamic load modulation of high power amplifiers (PAs) is presented. Design guidelines to overcome the common breakdown, and tunability problems of the varactors for high power applications are proposed. Based on the guidelines, using commercially available abrupt junction silicon varactors, a tunable matching network is built and measured. The matching network is then used for load modulation of a 1-GHz 7-W class-E LDMOS PA. Static measurements of the load modulated PA show that the power-added efficiency of the PA is improved by an absolute value of 10% at 10-dB backoff. This promising result proves, for the first time, the feasibility of load modulation techniques for high-power applications in the gigahertz frequency range.

A Design Technique for Concurrent Dual-Band Harmonic Tuned Power Amplifier

Abstract: In this paper, a novel technique to design concurrent dual-band high-efficiency harmonic tuned (HT) power amplifiers (PAs) is presented. The proposed approach is based on a methodology developed to design multifrequency passive matching networks, which allows concurrent operability. The network design criterion is heavily investigated and later generalized both from the theoretical and practical point of view. The design, realization, and the complete characterization of a concurrent dual-band high-efficiency HT PA is finally described. A 1-mm gate periphery GaN HEMT device was used for the design and realization of the PA operating concurrently at 2.45 and 3.3 GHz. The measurement results have shown 53% and 46% drain efficiency at 33- and 32.5-dBm output power in the two targeted bands if operated in continuous wave single mode. In concurrent mode, 35% average efficiency was achieved with two simultaneously applied orthogonal frequency-division multiplexing signals.

Range-Adaptive Wireless Power Transfer Using Multiloop and Tunable Matching Techniques

Abstract: In this paper, a range-adaptive wireless power transfer (WPT) system is proposed to achieve high efficiency over a wide range of distances by using tunable impedance matching techniques. A multiloop topology is employed to greatly reduce the variation in the input impedance of the WPT system with respect to the distance, where one of the four loops with a different size is selected, depending on the distance. It enables the design of a simple tunable matching circuit using a single variable capacitor. An algorithm is written to find the optimum loop and capacitance in the matching network, based on the measured input return loss using a directional coupler and rectifiers. The fabricated WPT system shows a range-adaptive operation with high efficiency over a wide range of distances. It attains 48% efficiency at a distance of 100 cm with a maximum efficiency of 92% at a distance of 10 cm.

Adaptive Impedance-Matching Techniques for Controlling L Networks

Abstract: The link quality of mobile phones suffers from antenna mismatch due to fluctuating body effects. Techniques for adaptive control of impedance-matching L networks are presented, which provide automatic compensation of antenna mismatch. To secure reliable convergence, a cascade of two control loops is proposed for independent control of the real and imaginary parts of impedance. A secondary feedback path is used to enforce operation into a stable region when needed. These techniques exploit the basic properties of tunable series and parallel LC networks. A generic quadrature detector that offers a power-independent orthogonal reading of the complex impedance value is presented, which is used for direct control of variable capacitors. This approach renders calibration and elaborate software computation superfluous and allows for autonomous operation of adaptive antenna-matching modules.