ELECT An area-efficient CMOS impulse radio ultra-wideband (IR-UWB) transmitter capable of generating variable orders of Gaussian pulses is presented. The core of the pulse generator is constructed using the cascade connection of RC differentiator networks separated by tunable amplifiers. Tuning the bias current of the amplifier using a voltage-controlled current-source allows for generation of ...

This paper presents the preliminary results on the possible reception of over-horizon VHF radio signals from a FM (frequency modulation) transmitter during abnormal situations (probably in close association with earthquakes). The transmitter is FM Sendai (frequency = 77.1 MHz) and the receiving station is our university (UEC) at Chofu, Tokyo, with the transmitter-receiver distance being about 3...

TAMPERE UNIVERSITY OF TECHNOLOGY Master’s Degree Program in Radio Frequency Electronics Kiayani, Adnan Qamar: DSP Based Transmitter I/Q Imbalance CalibrationImplementation and Performance Measurements. Master of Science Thesis, 80 Pages October 2009 Examiners: Prof. Mikko Valkama and MSc. Lauri Anttila Funding: Finnish Funding Agency for Technology and Innovation (TekeS), Academy of Finland, Te...

This paper describes a study of how 2.45GHz electromagnetic waves propagate indoors. 2.45GHz is a typical Bluetooth frequency. Propagation models with both one and several transmitters have been made using an advanced computer program. Furthermore, a model of the propagation of 433MHz radio waves has been made and used as a standard point of comparison. To make sure that such models are reliabl...

A new ultrasound wireless positioning system is developed that gives the surgeon the exact 3D location and orientation of the instruments in the patient. The measuring system employs ultrasound markers/ transmitters placed on the instruments, outside of the human body. Knowing the dimensions of the usually rigid instruments it is possible to calculate their position and orientation inside the p...

The successful realization of a Wireless Body Area Network (WBAN) requires innovative solutions to meet the energy consumption budget of the autonomous sensor nodes. The radio interface is a major challenge, since its power consumption must be reduced below 100μW (energy scavenging limit). The emerging Ultra-WideBand (UWB) technology shows strong advantages in reaching this target. First, most ...

In cognitive radio, secondary users wittily occupy the spectrum hole and enhance the efficiency at the right location and time. Secondary users reward a chance to access primary user band with the aid of smart cognitive radio technology. In this study we explore the idea of secondary access spectrum through using the cognitive radio network in which the secondary user shares the spectrum with t...

This paper presents a development of a wideband deltasigma modulator for fully digital GHz transmitters. The fully digital RF transmitter is developed as a promising solution for software defined radio (SDR) terminals and applications. The fully digital transmitter consists of a delta-sigma modulator, a highspeed multiplexer and a switching-mode power amplifier. The speed limitation of delta-si...

This paper describes a concept of an RFDP (Radio Frequency Development Platform) for RF-transmitters and RF-receivers. With this platform the time effort for the development process can be reduced and prototypes for different communications standards which are defined at different frequencies can be built faster. Also modifications, e.g. if new analog components are available, can be implemente...

IEEE 802.11 and Bluetooth are the two different wireless systems that share the same frequency band in 2.4 GHz and are likely to interfere with each other if operating in the same environment and thus experience a severe decrease in throughput. The devices equipped with IEEE 802.11 and Bluetooth are mobiles, laptops, watches and many more and in future with WiMAX. Result is the number of co-loc...