Efficient front end and antenna implementation

摘要

A tightly integrated combined transmit and receive dual quadrifilar antenna is provided. The antenna comprises four helical transmit elements and four helical receive elements disposed about a common axis. A receiver front end includes an arrangement of two 90 degree hybrids which serve to effectively reject signals cross coupled from the transmit elements back into the receive elements, while still allowing the receiver to receive signals.

主权项

1. An antenna assembly comprising:
a set of four transmit antenna elements including a first transmit antenna element, a second transmit antenna element, a third transmit antenna element and a fourth transmit antenna element, wherein said set of four transmit elements are arranged in order about an axis and are equally spaced about said axis in azimuth angle; a set of four receive antenna elements including a first receive antenna element, a second receive antenna element disposed adjacent said first receive element, a third receive antenna element disposed adjacent said second receive antenna element and a fourth receive antenna element disposed adjacent said third receive antenna element and said first receive antenna element, wherein said set of four receive antenna elements are arranged in order about said axis, equally spaced about said axis in azimuth angle; a transmitter front end coupled to said set of four transmit elements; a receiver front end coupled to said set of four receive elements.