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This paper presents a technique to reduce the noise figure of a passive mixer-first receiver front-end. By using lower than 50Ω switch resistance in the current-mode passive mixer and introducing a positive feedback from baseband to the RF-input, it can be well matched close to fLO while achieving a noise figure below 3dB, which is otherwise a fundamental limit. A quadrature front-end prototype fo
This paper presents an inductorless ultra-low power frontend for applications such as sensor networks and medical implants. By using a completely inductorless topology the chip area is just 0.017mm2, excluding pads. A real input impedance of 300Ω is achieved with current feedback. Manufactured in 65nm CMOS, it measures more than 17dB gain from 100MHz to 2000MHz while consuming only 175μW from a 0.
In this position paper we give an outline of the Palcom platform for pervasive computing and some of the design issues. With this as a background we initiate a discussion of the balance between the user being in control, and the system behaving in a helpful way.
We developed a mobile system for collecting and communicating heart rate data in real-time using low cost, commonly available equipment. This system could be used to monitor patients with cardiac arrhythmia over long periods of time, hopefully increasing the chance of capturing and recording an actual fibrillation, which rarely is the case today. Such recordings are useful for physicians to find t
In this paper, an efficient technique to enhance the isolation between two closely spaced PIFAs for MIMO mobile terminals is introduced. The proposed decoupling method is based on a T-shape slot impedance transformer and it enables an inter-PIFA spacing of 1 mm to be achieved. The 10 dB impedance bandwidth and 20 dB isolation bandwidth cover the 2.4 GHz WLAN band (2.4-2.48 GHz), with a maximum iso
Context: Duplicate detection is a fundamental part of issue management. Systems able to predict whether a new defect report will be closed as a duplicate, may decrease costs by limiting rework and collecting related pieces of information. Goal: Our work explores using Apache Lucene for large-scale duplicate detection based on textual content. Also, we evaluate the previous claim that results are i
Age of Information (AoI) is a relatively new metric introduced to capture the freshness of a particular piece of information. While throughput and delay measurements are widely studied in the context of dense IEEE 802.11 Wireless LANs (WLANs) little is known in the literature about the AoI in this context. In this work we study the effects on the average AoI and its variance when a sensor node is
In this paper, we investigate the impact of power amplifier (PA) nonlinear distortion in pre-coded multi-user large antenna or massive MIMO downlink systems. First, detailed signal and system models are derived for the received signal at single-antenna user equipment (UE) under channel-aware linear precoding in the base-station combined with behavioral models for the individual PA units, covering
In this paper, we study a flexible routing strategy for demand protection and a corresponding optimization problem for networks that permanently experience fluctuations of the capacity available on their links. This is an important and novel topic as limited link availability is a fundamental feature of wireless networks; yet majority of work in survivable network design is restricted to total fai
A two-stage mm-wave power amplifier (PA) is presented. Designed in a 65 nm CMOS process, the PA employs capacitive neutralization in each stage for increased differential isolation and gain. Baluns are used for single-ended input/output signal to balanced signal conversion, and the interstage matching consists of a 2:1 transformer. With a 1.2 V supply, at 67 GHz, measurements show a gain of 16.8 d
The increasing number of mobile devices and high-speed services accelerate the growth of traffic in cellular backhaul networks. The traditional technologies used in the backhaul, copper, radio links and optical fibers, either cannot offer high data-rate, or are expensive. In this paper, we propose mixed integer programming models to facilitate upgrading the cellular backhaul using the free space o
