Cognitive Radio (CR) and Software Defined Radio (SDR), concepts which were mere proposals to solve the population of services over the past two decades, are now enabled by novel materials and components to offer fully reconfigurable devices. Thus, a convergence of services can be attained within a reduced, or even single RF (Radio Frequency) signal path in the device. A solid design of reconfig...

The undergraduate electrical engineering curriculum at Embry-Riddle Aeronautical University includes a three-course sequence in electromagnetism, radio frequency systems, and the RF laboratory (taken concurrently with the RF class). These courses are designed to support novice students in attaining the final learning objective of the RF Lab: the design and understanding of a simple digital radi...

The fast development of wireless communication systems requires more flexible and cost effective radio architectures. A long term goal is the software defined radio, where communication standards are chosen by reconfiguration of hardware. Direct analog to digital conversion of the radio frequency (RF) signal is still unrealistic at present time, due to the high requirements imposed on the analo...

An integrated circuit implementation of a PSK backscatter modulator for passive radio frequency identification (RFID) transponders is proposed. Such modulator offers a significant reduction of the power consumption with respect to other schemes already presented in the literature. Furthermore, the topology of the proposed modulator allows us to control its output resistance so that only a negli...

A scheme of frequency hopping spread spectrum (FHSS) frequency synthesizer suitable for synthesis of radio-frequency (RF) carrier signal in very high frequency (VHF) band is proposed, implemented and tested. The synthesizer is based on the direct digital frequency synthesis (DDFS or DDS) and phase locked loop (PLL) with dynamic monitoring of varicap’s voltage to reduce switching time. The resul...

A comprehensive consideration of loading effects is essential to the design/analysis of high-frequency MRI radio frequency (RF) coils. In this study, a hybrid finite difference time domain (FDTD)-method of moments (MoM) simulation method is implemented for the accurate evaluation of RF coil-tissue interaction. Using this approach, the RF coil is modelled using the MoM algorithm, and the biologi...

We present a continuously tunable nonrecursive radio-frequency (RF) photonic filter. The filter provides fine tuning through the use of a novel RF phase shifter and coarse tuning using an all optical variable time delay. This architecture permits wide-band continuous tuning of the filter null frequency and is useful in applications such as moving target indication (MTI) in an airborne radar.

The two signals inserted into the two input ports are usually the Local Oscillator signal, and the incoming (for a receiver) or outgoing (for a transmitter) signal. To produce a new frequency (or new frequencies) requires a nonlinear device. In a mixing process if we want to produce an output frequency that is lower than the input signal frequency, then it is called down-conversion and if we wa...

Precise indoor localization of wireless nodes remains a challenge today. While there are radio-frequency (RF) methods that offer significant advantages, the balance between accuracy, range, and cost is suboptimal for many applications. Radio interferometry has been shown to be effective outdoors, however, its applicability indoors has not been demonstrated mainly due to its sensitivity to multi...

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...