Frequency-scan traveling wave antenna

Abstract

A frequency-scan traveling wave antenna receives radio frequency (RF) energy at an input port, passes the energy through a quarter wave transformer to a first radiator element in an array of radiator elements, each pair of radiator elements being connected by a respective delay line. Each radiator element includes an input port of known characteristic impedance connected to an impedance matching section which compensates for that element's radiated power. Each radiator element has an output port with a section of transmission line disposed between a main radiator section of said radiator element and said output port, and impedance matched to the output port. In one embodiment, each delay line includes a plurality of delay line sections, with adjacent delay line sections being mutually perpendicular. In a second embodiment, each delay line includes a plurality of delay line sections disposed in meandering form.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention generally relates to a frequency-scan traveling wave antenna, and more particularly to a frequency-scan traveling wave antenna which operates at frequencies in the millimeter wave range.2. Description of the Prior ArtFrequency-scan traveling wave antennas are known in the art. Typically, uses of such antennas include their use in collision avoidance radar and in imaging radar. However, such frequency-scan traveling wave antennas are burdened by disadvantages, and those disadvantages adversely affect the quality of their performance. This interferes with the use of such antennas as an effective component of collision avoidance radar systems and imaging radar systems.Problems with traveling wave antennas of the prior art include the following: inferior radiating element design, inadequate impedance match, insufficient power weighting accuracy, and inferior phase coherence across an array.Accordingly, there is a ...

AI Technical Summary

Benefits of technology

The present invention generally relates to a frequency-scan traveling wave antenna, and more particularly, to a frequency-scan traveling wave antenna which operates at millimeter wave frequencies. In particular, the present invention provides a high performance traveling wave antenna which scans by frequency, and which can be used effectively as a component of collision avoidance radar systems and imaging radar systems.

It is an additional object of the present invention to provide a frequency-scan traveling wave antenna which employs an arrangement of radiators and delay lines which is geometrically symmetric, thereby balancing stray radiation and minimizing the amount of degradation of the beam pattern and the side lobe levels due to radiation from the delay lines between the radiators.

Problems solved by technology

However, such frequency-scan traveling wave antennas are burdened by disadvantages, and those disadvantages adversely affect the quality of their performance.

This interferes with the use of such antennas as an effective component of collision avoidance radar systems and imaging radar systems.

Problems with traveling wave antennas of the prior art include the following: inferior radiating element design, inadequate impedance match, insufficient power weighting accuracy, and inferior phase coherence across an array.

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