Universal Equivalent Circuits for All Antennas - Jan 2022

Описание: MTT-SCV: Universal Equivalent Circuits for All Antennas - Jan 2022

Stephen D. Stearns (former Technical Fellow of Northrop Grumman Corporation) talks about antenna impedance fundamentals and decade bandwidth equivalent circuits and examples for wireless system design and measurement

Abstract:
Series and parallel RLC resonant circuits have long been the staple equivalent circuits for dipole and loop antennas despite being narrowband approximations. This paper shows how to make universal equivalent circuits for any antenna over any bandwidth.

Part 1 introduces the history of classical electric network synthesis and Smith charts and reviews antenna impedance and admittance properties.

Part 2 explains the modes of vibration of continuous structures, natural frequencies, feedpoint current, and impedance resonances.

The impedance function of any antenna can be accurately modeled by two of four universal equivalent circuits given computed or measured impedance data and a circuit optimizer. Examples of broadband universal equivalent circuits are shown for dipole, circular loop, and discone antennas over multi-octave and decade bandwidths. Broadband equivalent circuits are useful for interpolating between data points and performing lab tests without radiating. 1-port equivalent circuits are useful for making dummy loads for reflection experiments or match network testing. 2-port equivalent circuits are useful for transmission measurements.