Adaptive Nulling at HF Using a Compact Array of Active Parasitic Antennas.
Abstract
This parasitic array is a promising method of building an adaptive array in a tiny aperture. This is particularly attractive for HF. Both theory and experimental results are presented. The theory is established with respect to two models of a compact array, an impedance model and a transmission line model. The relationship between the models are derived. The models are then used to explore the null forming and adaptive control, with an emphasis on active terminations. Zeger-Abrams designed an electronically variable active termination. Experimental results were obtained from an array both passive and active terminations. Empirical results with active complex-valued terminations demonstrated the feasibility of simultaneously nulling multiple HF jammers with an adaptively controlled compact array having parasitic auxilliary elements and an unweighted main antenna. Finally, an algorithm to adaptively control the active terminations is derived. Originator-supplied keywords include: Active Parasitic Antennas, Adaptive Array, Complex Gradients, ECCM, Gradient Control, HF, Interference Cancellation, Nonlinear Control, Nulling Array, Parasitic Array, Scattering Parameters, Spatial Interference, and Cancellation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1985
- Accession Number
- ADA152582
Entities
People
- A. E. Zeger
- T. E. Jones