Levente Dudás

Experimental 13.56 MHz RFID cards on biodegradable substrates

The paper presents experimental research on investigating the production and testing aspects of ISO/IEC 14443 contactless RFID tags fabricated on biodegradable cellulose acetate (CA) biopolymer-based Printed Circuit Boards (PCB). Our approach reduces the harmful plastic waste by substituting the standard materials of the cards with biodegradable substrate. Also, with common PCB fabrication methodology the prototyping and production becomes cost-effective for the novel material. The paper will detail the manufacturing steps and the different aspects of production for the prepared cards. The preliminary functional results show promising examples of a functional, standard 13.56 MHz RFID reference cards.

The communication subsystem of Masat-1, the first Hungarian satellite

The first Hungarian satellite, Masat-1 is designed and built at the Budapest University of Technology and Economics. Instead of working from pre-built components, the members develop the whole satellite, including design, implementation and testing. This paper introduces the key issues about designing a small satellite, with a detailed description of the Communication subsystem. In the paper, special attention is being paid for the digital signal processing part of the development, as it is the key to fulfill the easy detection constraint. The possible solutions are examined and there is a recommendation of a method which could easily fulfill the proposed requirements.

Digital television broadcast -based passive radar research and development

Nowadays passive radars are gaining ground and become more popular. Now, that the so far insurmountable technological limitations begin to disappear, beside the theoretical researches the investigation of realizations with the recently available hardware technologies are becoming more important. This paper presents a feasibility experiment of such a passive radar that uses DVB-T (Digital Video Broadcast - Terrestrial) signal to detect airplanes. In this paper the he principle operation of the passive radar systems has confirmed both with simulations and measurements.

The spectrum monitoring system by Smog-1 satellite

Our aim is to design and develop a PocketQube-class satellite as one possible continuation of Masat-1, the first Hungarian satellite. The planned payload of Smog-1 is an UHF band spectrum monitoring system. This system is able to measure the UHF band digital terrestrial TV signal levels around the world on a low Earth orbit as RF smog. The spectrum measurement system were flown by high altitude meteorological balloon.

The communication and spectrum monitoring system of Smog-1 PocketQube class satellite

As one possible continuation of development of Masat-1, the first Hungarian satellite, in 2015, a group of student, from Faculty of Electrical Engineering and Informatics and Mechanical Engineering, decided to realize a PocketQube-class satellite, called Smog-1. Smog-1 is a 5 cm cubesat as PocketQube with less than 180 g mass. The aim of Smog-1 is to measure the radio frequency (RF) smog caused by human beings on the DVB-T band (Digital Video Broadcasting-Terrestrial).

Air traffic control radar tester

Our aim had been to develop a radar tester equipment for commercial and military services. The task is to create one (or more) target or clutter on the radar screen with given distance, velocity and fluctuation. This equipment is placed within few hundred meters from the radar, so it is able to analyze the whole radar system from the antenna, via microwave hardware elements, to the DSP unit.

Small sized synthetic aperture radar development

Synthetic aperture radar had been developed from the base-band digital unit to the analogue RF parts, based on solid state units, using pulse compression for radar imaging. Proper QPSK code is found for matched filter.

Receiver antenna array

Our aim is to develop a microwave receiver antenna system, which can form its radiation pattern (main lobe direction, null-point direction, structure of the side lobes), measure the direction of the RF source in milliseconds. In this paper we will show the theoretical background of the antenna system, the build-up of the realized system and some measurement results.

Implementation of a radar tester for air traffic control applications

In this paper we present a method, and a fully implemented and tested hardware, for testing the operation of primary radars, may it be used in air traffic control or in military service. The realization of the radar tester was based on the theory of controlled radar cross section (CRCS), this way creating spurious targets or clutters, with known parameters, on the screen of the radar. According to the difference between the created and the measured parameters (e.g. velocity, fluctuation and distance), any minor or major degradation or failure can be detected. The tester is capable of scanning the radar system from the antenna, via microwave hardware elements, all through to the digital signal processor (DSP) unit, achieving great diagnostic properties. Emphasis was put on the realisation of the hardware. The produced equipment was tested in real life using a primary ATC radar in Hungary, with satisfying results.

Vehicle relative movement estimation using microwave sensor

Microwave remote sensing based real vehicle movement estimator is under development. The application of this microwave sensor effectively increases the safety of traffic. The movement sensor provides further information about the estimation of the road-quality and the condition of shock-absorber, which are useful for the maintainer.