Planar microstrip Yagi antenna array

US5220335A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventor

• John Huang · Arcadia, US

Key dates

• Filing date: Feb 28, 1991
• Grant date: Jun 15, 1993
• Expiry date: Feb 28, 2011

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01Q19/005
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A directional microstrip antenna includes a driven patch surrounded by an isolated reflector and one or more coplanar directors, all separated from a groundplane on the order of 0.1 wavelength or less to provide endfire beam directivity without requiring power dividers or phase shifters. The antenna may be driven at a feed point a distance from the center of the driven patch in accordance with conventional microstrip antenna design practices for H-plane coupled or horizontally polarized signals. The feed point for E-plane coupled or vertically polarized signals is at a greater distance from the center than the first distance. This feed point is also used for one of the feed signals for circularly polarized signals. The phase shift between signals applied to feed points for circularly polarized signals must be greater than the conventionally required 90.degree. and depends upon the antenna configuration.