The application note summarizes the RF transmitter architectures of zero-IF, complex IF, high (real) IF, and direct RF before detailing the benefits of the direct RF transmitter for wireless applications, which have increased with the rise in smartphone and tablet computer use. As the application note shows, the superiority of a direct RF architecture with a high-performance DAC results in redu...

M ost readers will be broadly familiar with the concept of a radio direction finder (RDF). A basic RDF consists of a receiver and an antenna which can be rotated on its own axis. The direction of the transmitter is found by rotating the antenna for a signal peak or null. You can easily demonstrate the effect for yourself using a portable transistor radio fitted with a ferrite rod antenna. By tu...

A software defined radio (SDR) terminal promotes programmable realizations of the physical layer functionalities. A lot of research work has been done in applying digital signal processors (DSP) and field programmable gate arrays (FPGA) to implement the baseband functionalities of the physical layer. In this paper, the programmable solutions are extended to the radio frequency (RF) band for the...

High Data Rate Radio Transmitter for Cube Satellites

Initial theoretical studies of multi-spacecraft radio tomographic imaging of the magnetosphere have shown the potential scientific value of the technique. We report a series of multistatic radio propagation experiments with the goal of testing and verifying the capabilities of radio tomography. These experiments focused specifically on measuring the plasma-induced rotation of the wave polarizat...

Channel properties influence the development of wireless communication systems. Unlike wired channels that are stationary and predictable, radio channels are extremely random and don’t offer easy analysis. A Radio Propagation Model (RPM), also known as the Radio Wave Propagation Model (RWPM), is an empirical mathematical formulation for the characterization of radio wave propagation as a functi...