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Nano- and pico-satellites are currently used as low cost in-orbit-demonstrators of new technologies or for the university research. These satellites are launched to the low Earth orbits and radio commanded from the ground control stations. Most of them are equipped with narrow band transceivers working in UHF radio amateur frequency band, reaching only low data transmission rates. Low Earth orbits...
The paper presents a design of a four way signal splitter working in L frequency band, for standard GNSS (Global Navigation Satellite Systems) signals. These splitters are used when more than one receiver has to be connected to one signal source, like an antenna, a signal distribution socket or a test signal generator. The advantage of the solution is realization by a PCB structure, without need of...
This paper is devoted to the proposal of a highly efficient carrier phase synchronization subsystem for Software Defined Receiver. The proposed feedback phase-locked loop carrier synchronizer is suitable for parallel implementation on an FPGA for QPSK with the possibility of extension for m-QAM modulation. Direct Digital Synthesizer uses CORDIC algorithm in rotation mode for calculation of the sine...
This article describes one possible solution of bias networks for special broadband RF amplifiers. The purpose is amplification special pulse signals from particle detectors, which demands well defined time domain properties. The problem is demonstrated on two basic prototypes with different amplifier chips used in. Both are designed using standard components with poor results and using special broadband...
The increasing popularity of Software Defined Radio is forcing complex digital signal processing blocks to be implemented in parallel design flow on FPGA or ASIC. Digital filters are necessary in transmitter / receiver side and FIR filters are often chosen for their beneficial properties against IIR filters. Symbol synchronization subsystem also maintains digital filters for interpolation purpose...
This article deals with screen printed antennas on textile substrate that are used for data transmission between intelligent fireman suits. Today the smart textiles are developed in the whole world and research works are focused on integration of electronic devices and systems into textiles. There are different technologies how to do it. Screen printed electronic devices on textile substrates are...
Digital filters are necessary in digital transmitter / receiver side and popularity of Software Defined Radio (SDR) is forcing complex digital signal processing blocks to be implemented in parallel design flow on FPGA or ASIC. The goal of this paper is to develop efficient pipelined polyphase FIR filter structures in VHDL language for RTL synthesis on FPGA. The proposed structures contain fully parallel...
Four basic methods for measuring RF circuit frequency response were implemented and tested on the popular software defined radio system based on popular GNU-radio software package and on the Ettus USRP hardware. Properties, advantages and disadvantages of this solution were studied and are described in this paper. Using the proposed platform for measurement is interesting, because the equipment needed...
The increasing popularity of Software Defined Radio is forcing complex digital signal processing blocks to be implemented in parallel design flow on FPGA or ASIC. One of the main sections of digital receiver is symbol synchronization block. The goal of this paper is to develop efficient Non-Data-Aided (NDA) feedback PLL-based synchronization scheme in VHDL language for RTL synthesis on FPGA. The first...
The paper is concerned with digital modulations design using an Altera programmable device. The binary phase shift keying (BPSK) modulator and the BPSK demodulator are designed. A simulation on the proposed design is performed and the design is implemented in the programmable device. The simulation and implementation are performed including an effect of transmission channel. Measurements and results...
At present a CW beacon with Morse code or OOK modulation is still commonly used in picosatellites (especially in CubeSats) for signaling that picosatellite is currently rising above the horizon and for limited telemetry transmission about picosatellite functionality. This transmission with limited EIRP could be replaced by proposing group of hybrid modulations DM-FSK/DQPSK and M-FSK/DQPSK with better...
The paper deals with a radio beacon design for the picosatellite, which will be improved in terms of reliable operation. Our radio beacon is equipped with several features, such as the safety satellite communication bus interface, the power supply protection and self check, the watchdog, the internal software diagnostics and the radio transmitter or power amplifier diagnostics. Also, the antenna and...
This article deals with possibilities of the automatic testing of multimedia units. The aim of the work was to design and realize an automatic test system for a functional parameter measurement of multimedia units. The system was built up by the help of individual measuring devices and the designed multiplexer. The entire system is controlled by the control computer. For the control computer was necessary...
A radio communication between picosatellite and ground station has not stable conditions during the receiving of signal. The radio link budget is influenced by changes in communication distance, by changes in picosatellite antenna pointing and by several more factors. Therefore the received signal quality is varying as well as theoretical channel capacity and the effective communication systems have...
In this paper a special system structure called dissipation normal form is briefly described. Stability of any system with this structure is given by sign of the only one so called dissipation parameter. It is known that suitable non-linearity in this parameter leads to non-linear oscillation including chaotic oscillation what can be used for chaotic systems synthesis. In this paper the possibility...
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