Beampattern analysis of frequency diverse array radar: a review

Electronic beam steering is an essential feature of state-of-the-art radar systems. Conventional phased array (PA) radars with fixed carrier frequencies are well-known for electronically steering their beam with high directivity. However, the resulting beampattern is angle-dependent but range-independent. Recently, a new electronic beam steering concept, referred to as frequency diverse array (FDA) radar, has attracted increasing attention due to its unique range-angle dependent beampattern. More importantly, the FDA radar employs a small frequency increment across the array elements to achieve beam steering as a function of angle, range, and time. In this paper, we review the development of the FDA radar since its inception in 2006. Since the frequency offset attaches great importance in FDAs to determine the beampattern shape, initially much of the research and development were focused on designing the optimal frequency offsets for improved beampattern synthesis. Specifically, we analyze characteristics of the FDA beampattern synthesis using various frequency offsets. In addition to analyzing the FDA beampattern characteristics, this study also focuses on the neglected propagation process of the transmitted signals in the early FDA literature, and discuss the time-variant perspective of FDA beampatterns. Furthermore, FDA can also play a significant role in wireless communications, owing to its potential advantages over the conventional PAs. Therefore, we highlight its potential applications in wireless communication systems. Numerical simulations are implemented to illustrate the FDA beampattern characteristics with various frequency offset functions.

Radio link system solutions for mobile platforms operatingin sea environment

In this paper radio link system solutions operating in 300 MHz — 3000 MHz range and sea environment were described. Solutions with more than one frequency and wave propagation models for horizontal not more than 50 km and far range were described. In the paper the results of actions taken design and construction solutions adopted were presented, aimed to contribute to ensure the reliability of the system, among other things, by implementing mechanisms for collecting and processing information. This solutions allow resources management to automatically adjust the transmission parameters configuration to the bitrate and range requirements. Available configurations can be extended with active part and electronic beam steering with one or more beams. The paper describes antenna systems ability of transmission parameters adaptation to get the range required.