Low-distortion, low-loss varactor-based adaptive matching networks, implemented in a silicon-on-glass technology
12 Jun 2005-pp 389-392
TL;DR: A low-loss, low-distortion continuously tunable matching network, is demonstrated at 2 GHz in a silicon-on-glass varactor IC technology, and exhibits less than 0.5 dB loss.
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.
Citations
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TL;DR: 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 to achieve the desired source and load impedance tunability.
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
226 citations
TL;DR: In this paper, the design of varactor-based tunable matching networks for dynamic load modulation of high power amplifiers (PAs) is presented, and the results show that the power-added efficiency of the load modulated PA is improved by an absolute value of 10% at 10-dB backoff.
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.
171 citations
Cites methods from "Low-distortion, low-loss varactor-b..."
...The procedure is, however, general and can be used as design guidelines for any PA, and matching network topology....
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TL;DR: In this article, a reconfigurable output network for a multiband power amplifier (PA) for universal mobile telecommunications system (UMTS) handset applications is proposed, which can reconfigure the output power and the output path, as well as the frequency.
Abstract: A new practical reconfigurable output network for a multiband reconfigurable power amplifier (PA) is proposed for universal mobile telecommunications system (UMTS) handset applications. The proposed reconfigurable network can reconfigure the output power and the output path, as well as the frequency. It consists of a power-reconfigurable network, a frequency-reconfigurable network, and a path-selection network. In this paper, its reconfiguration principle is described to extract key design parameters for the reconfigurable PA implementation. To demonstrate the performance of the proposed structure, a 5 mm × 6 mm multiband reconfigurable PA module is developed for UMTS high- and low-frequency band application. The fabricated PA module can cover any three bands out of five popular high- and low-frequency UMTS bands. To enhance the efficiency during low output power operation, the authors' stage-bypass technique is also employed. The fabricated PA module showed adjacent channel leakage ratios better than -39 dBc up to the rated linear output power and power-added efficiencies of higher than 39% at Pout=28 dBm over all the UMTS frequency bands. Efficiency degradation was limited to less than 2% compared to the single-band PA. Measured RF performance of the reconfigurable PA validates the usefulness of the proposed reconfigurable structure for multiband UMTS applications.
49 citations
TL;DR: In this paper, a benchmark of tunable and switchable devices at microwave frequencies is presented on the basis of physical limitations to show their potential for reconfigurable cellular applications, focusing on the quality factor (Q) and tuning ratio (eta) as figures of merit.
Abstract: A benchmark of tunable and switchable devices at microwave frequencies is presented on the basis of physical limitations to show their potential for reconfigurable cellular applications. Performance limitations are outlined for each given technology focusing on the quality factor (Q) and tuning ratio (eta) as figures of merit. The state of the art in terms of these figures of merit of several tunable and switchable technologies is visualized and discussed. If the performance of these criteria is not met, the application will not be feasible. The quality factor can typically be traded off for tuning ratio. The benchmark of tunable capacitor technologies shows that transistor-switched capacitors, varactor diodes, and ferroelectric varactors perform well at 2 GHz for tuning ratios below 3, with an advantage for GaAs varactor diodes. Planar microelectromechanical capacitive switches have the potential to outperform all other technologies at tuning ratios higher than 8. Capacitors based on tunable dielectrics have the highest miniaturization potential, whereas semiconductor devices benefit from the existing manufacturing infrastructure.
41 citations
Cites methods from "Low-distortion, low-loss varactor-b..."
...Rs can be minimized by using thick metals and substrate-transfer techniques [2]....
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Patent•
18 Jun 2008TL;DR: In this article, a method of manufacturing a radiation detector and a lithographic apparatus comprising of a radiation sensor and a radon sensor was described. But this method was not suitable for the case of charged particles.
Abstract: The invention relates to a radiation detector (1), a method of manufacturing a radiation detector and a lithographic apparatus comprising a radiation detector. The radiation detector (1) has a radiation-sensitive surface. The radiation-sensitive surface is sensitive for radiation with a wavelength between 10 - 200 nm and/or for charged particles. The radiation detector (1) has a silicon substrate (3), a dopant layer (5), a first electrode (7) and a second electrode (9). The silicon substrate (3) is provided in a surface area (10) at a first surface side with doping profile of a certain conduction type. The dopant layer (5) is provided on the first surface side of the silicon substrate (3). The dopant layer has a first layer (5a) of dopant material and a second layer (5b). The second layer (5b) is a diffusion layer which is in contact with the surface area (10) at the first surface side of the silicon substrate. The first electrode (7) is connected to dopant layer (5). The second electrode (9) is connected to the silicon substrate (3).
35 citations
References
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TL;DR: In this paper, the biaxial tensile stress imposed by Si on BST made the polar axis oriented in plane was found to increase the dielectric permittivity with increase in film thickness.
Abstract: Ferroelectric thin films are currently being used to develop tunable microwave circuits based on the electric-field dependence of the dielectric constant. (Ba0.5Sr0.5)TiO3 (BST) films prepared by sputtering on Pt/TiO2/SiO2/Si substrates are found to exhibit a capacitance change (tunability) of nearly 4:1. Higher tunability has been attributed to the (100) texturing of the BST films and is a result of the biaxial tensile stress imposed by Si on BST making the polar axis oriented in plane. Electrical characterization shows that the dielectric permittivity increases with increase in film thickness (up to ∼200 nm).
313 citations
TL;DR: In this article, a planar dynamically reconfigurable double-stub tuners that utilize electrostatically activated microelectromechanical system (MEMS) switches are presented. But their performance is limited by the range of loads that need to be matched.
Abstract: This paper presents novel planar dynamically reconfigurable double-stub tuners that utilize electrostatically activated microelectromechanical system (MEMS) switches. The tuners operate in the 10-20 GHz frequency range and have stubs that consist of a digital capacitor bank. Each bank has a predetermined number of capacitors that can be selected through the activation of appropriate MEMS switches. The value and number of capacitors is dictated by the range of loads that needs to be matched. Simulated and measured results from several designs are presented. A 4 bit /spl times/ 4 bit tuner that can match loads with 1.5 /spl Omega/
146 citations
08 Jun 2003
TL;DR: Load modulation is a new technique in which amplitude-modulated signals are produced with high efficiency by dynamic variation of the load impedance of the power amplifier as discussed by the authors, which is achieved by a T network with a pair of highvoltage MOSFETs that act as a voltage-variable capacitor.
Abstract: Load modulation is a new technique in which amplitude-modulated signals are produced with high efficiency by dynamic variation of the load impedance of the power amplifier. The prototype MOSFET PA operates in class E and produces a peak output of 19 W at 30 MHz with an efficiency of 66 percent. Load modulation is accomplished by a T network with a pair of high-voltage MOSFETs that act as a voltage-variable capacitor. The envelopes of a variety of different signals are successfully generated. For a Rayleigh (multi-carrier) envelope with a 10-dB peak-to-average ratio, the average efficiency is twice that achieved in linear operation of the same PA.
135 citations
17 Jun 2005
TL;DR: In this article, a diode-based circuit topology for high-Q tunable capacitive elements is presented, where the measured IM3 improvement compared to traditional single varactor tuning techniques is greater than 30 dB.
Abstract: Varactor diode-based circuit topologies, which can act as high-Q “distortion-free” tunable capacitive elements, are presented. These diodes are implemented in a novel ultra low-loss silicon-on-glass technology, with resulting measured Q's of over 200 at 2 GHz. The measured IM3 improvement compared to traditional single varactor tuning techniques is greater than 30 dB.
117 citations
"Low-distortion, low-loss varactor-b..." refers background in this paper
...As altematives to the above techniques, we have recently demonstrated in [4] that varactor based tunable capacitors, can be implemented with a very high Q (>lo0 @!...
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TL;DR: Close-form expressions for intermodulation distortion produced by variable-capacitance diodes in series- and parallel-tuned circuits are derived and verified by experiment at frequencies up to 200 MHz.
Abstract: Distortion in variable-capacitance diodes is analyzed using the Volterra series approach. Closed-form expressions for intermodulation distortion produced by variable-capacitance diodes in series- and parallel-tuned circuits are derived and verified by experiment at frequencies up to 200 MHz. The choice of the diode capacitance law exponent for minimum distortion is investigated. Distortion in multiple-diode connections is analyzed and the advantages of the back-to-back connection is shown. Calculation shows the elimination of third-order distortion for n=0.5 in this connection.
101 citations
"Low-distortion, low-loss varactor-b..." refers background in this paper
...Meyer et, al. showed that uniformly doped varactor diodes with a capacitance voltage power-law coefficient (n=U.5), exhibit essentially no distortion when operated in the anti-series configuration [5]....
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