Paul Hallbjörner

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In the Swedish railway system there are more than hundred stationary detectors placed all over the country, detecting e.g. overheated wheel bearings. Instead of monitoring the bearings at fixed locations, wireless sensor networks can be used to continuously monitor the bearings. Upcoming problems are thereby more easily detected. There are several problems(More)
This paper presents building blocks for a proposed automotive intermodulation radar for detecting and identifying vulnerable road users (VRUs). The intermodulation radar transmits at two frequencies and it has receivers both for normal reflections and for reflections from VRUs at the intermodulation frequency. A possible radar architecture is presented and(More)
An expression is derived for the maximum proportion of remaining samples in the sample selection technique for mode-stirred chamber measurements. The limit is independent of the selection algorithm used. The limit is verified in simulations as well as measurement examples. VC 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2608–2610, 2011; View(More)
This paper proposes and analyses a block acknowledgment (BACK) mechanism for Wireless Sensor Networks (WSNs). This BACK mechanism enables the aggregation of several acknowledgment (ACK) responses into one special packet. A contention based random medium access control (MAC) protocol with multiple nodes sharing the same medium is considered. The Sensor Block(More)
Single-chip 60 GHz transmitter (TX) and receiver (RX) MMICs have been designed and characterized in a 0.15 m ( 120 GHz/ MAX 200 GHz) GaAs mHEMT MMIC process. This paper describes the second generation of single-chip TX and RX MMICs together with work on packaging (e.g., flip-chip) and system measurements. Compared to the first generation of the designs in a(More)
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