Newsletter | December 7, 2020

12.07.20 -- The Rebirth Of HF Technologies


Bringing back the lost art of HF technologies for resilient and mission-critical local and global communications

The Rebirth Of HF

HF, or “high frequency” technology, usually refers to signals with frequencies in the 3 MHz to 30 MHz range; although, many practical cases extend these frequencies as low as 1.5 MHz. Government, military, and commercial broadcasters are able to reach listeners worldwide using HF frequencies. This article explores the unique properties of HF that enable global communications.

Understanding NVIS

The near vertical incidence skywave (NVIS) is an HF propagation mode where signals are transmitted towards, and returned from, the ionosphere almost vertically in order to provide local or regional coverage. This article discusses the underlying technical principles of NVIS, the different types of antennas for NVIS operation, and the operational aspects of NVIS.

Utilizing Active Antennas For Radio Monitoring

This article discusses the fundamental working principles of active antennas as well as how they differ compared to passive antennas. In addition, the important parameters relating to active antennas are explained and typical system applications are presented, including a comparison with passive antenna solutions and a focus on radio monitoring in the HF frequency range. 

Transmit And Receive Testing Of Digital Waveforms

This application note focuses on the use of the digital radio capabilities for measurements on radio transceiving devices in terms of their functionality and parameter characterization. It also addresses readers who develop, produce, or optimize digital radio transmitting and receiving devices or maintain analog radio communication equipment alongside those with digital modulation. 

Speeding Up Reflection Measurements On Antenna Systems

Reflection measurements are a common way of assessing antenna system performance. When a minimum amount of the transmitted signal is reflected, it indicates that the transmission energy can reach the intended coverage. Undesired high reflection causes the system to be inefficient and can damage components. Learn what solutions aid fast and efficient reflection measurements on antenna systems to get it right the first time.