Radar imaging

SIGNAL (programming language)

Interference (communication)

Algorithm

Single antenna interference cancellation

Beam (structure)

Engineering

Frequency domain

Telecommunications

Computer science

Antenna (radio)

Adaptive beamformer

Adaptive filter

Beamforming

Thermodynamics

Physics

Mathematics

Optics

Electronic engineering

Domain (mathematical analysis)

Mathematical analysis

Space-time adaptive processing

Programming language

Channel (broadcasting)

Clutter

Radar

Side lobe

Main lobe

Radar engineering details

Computer vision

Jamming

IRE Transactions on Antennas and Propagation

Initial applications of adaptive array theory to the radar sidelobe jamming problem ignored the problem of incidental cancellation of the desired signal returns. In more recent applications, longer transmitted waveforms have combined with returns from extended clutter and/or strong targets to create a more serious signal cancellation problem. There are several ways in which the adaptive processor can be constrained from responding to desired main lobe target returns while maintaining good cancellation of interference in the sidelobes. This paper examines the major techniques for constraining the response of the adaptive processor, including methods of controlling the response of the array in the absence of external interference. Time domain and frequency domain techniques are discussed. The majority of the discussion is devoted to angle domain techniques such as pilot signals, preadaption spacial filtering, and control loop spatial filtering. Analysis is presented showing the relationship between these techniques. Finally, examples are given showing the effects of these constraints as well as control of the quiescent array pattern.

Adaptive arrays with main beam constraints