INVESTIGATION OF USE OF SUPERIMPOSED SURFACE WAVE MODES.
Final rept. no. 1, 1 Feb 65-31 Jan 66,
HUGHES AIRCRAFT CO FULLERTON CALIF
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A novel method of achieving a matched radiating element in a phased array antenna over a specified scan angle has been investigated. The radiating element consists of an open-ended waveguide supporting the two lowest order modes. Each of these modes excites a surface w ve along the array. When appropriately super-imposed, the two surface waves yield the correct shape of mutual impedances which produce a constant driving point impedance over a specified scan angle when all elements in the array are driven. The existence of these surface waves has been verified by the experimental investigations. The near fields, both of the radiation and the induction types, were shown to be important under certain conditions. Using a scattering formulation instead of impedance formulation, this method of control of driving point impedance can be regarded as combining two or more modes such that the reflections of these modes tent to cancel each other at the driven terminals. A VSWR of less than 1.2 to 1 over a plus or minus 60 degrees scan angle from broadside was obtained theoretically for a linear array of open-ended waveguides supporting the two lowest order modes. Author
- Electrical and Electronic Equipment
- Electricity and Magnetism
- Radiofrequency Wave Propagation