Stalk-Type Field Probe With Orthogonal Dipoles
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Solution Overview
Problem
Conventional broadband field probes face difficulties in measuring DC voltage across detector diodes, avoiding metal objects and conductors, and making reliable mechanical connections that do not impair frequency response.
Innovation Solution
The field probe features three mutually orthogonal dipole antennas and feedlines formed on a unitary circuit board, with dipoles and feedlines configured to be in close proximity without mechanical interference, using thin film resistive elements and a shunt circuit to maintain a flat frequency response and minimize isotropic deviation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional conductive wiring is used to supply power and control signals to electronic circuitry, then electrical connections are established, but interference with incident radiation and measurement accuracy deteriorates
Solution Approach 1:
The patent replaces conventional conductive wiring with a non-conductive feedline structure. The feedline is constructed as a hollow non-conductive cylinder with conductive elements disposed within, eliminating traditional metal conductors that interfere with electromagnetic field measurements while still providing necessary electrical connections to the electronic circuitry.
Solution Approach 2:
The patent introduces a non-conductive feedline as an intermediary structure between the sensor and electronic circuitry. This feedline serves as a mediator that provides mechanical support and electrical connection pathways without using conventional conductive wires that would directly interfere with the measured electromagnetic fields.
2Measurement precision
If metal objects and conductors are avoided near sensors, then measurement interference is reduced, but manufacturing and connection reliability become more difficult
Solution Approach 1:
The patent merges the feedline structure with the sensor assembly by integrating the non-conductive feedline directly into the sensor housing. The conductive elements are disposed within the feedline in a fixed, pre-positioned manner, eliminating the need for separate connection steps and ensuring consistent positioning that avoids measurement interference.
Solution Approach 2:
The patent uses a hollow non-conductive cylindrical feedline structure that provides both mechanical support and electrical isolation. This shell-like structure allows for reliable manufacturing and assembly while maintaining the necessary electrical properties and geometric stability for accurate field measurements.
3Productivity
If dipoles are placed in close proximity on a unitary circuit board, then manufacturing efficiency is improved, but mechanical interference between dipoles may occur
Solution Approach 1:
The patent resolves potential mechanical interference between closely-spaced dipoles by utilizing three-dimensional spatial arrangement. The dipoles are positioned at specific angles (54.7 degrees) relative to the feedline axis, and their elements are oriented in different spatial dimensions, allowing them to be in close proximity on a unitary circuit board without interfering with each other's electromagnetic fields.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration allows for improved manufacturing efficiency, a broad frequency range, and low isotropic deviation, enabling accurate electric field measurements with reduced interference and improved reliability.
Implementation Method 1
A typical probe sensor includes a detecting diode that delivers a DC signal the amplitude of which corresponds to the magnitude to the field incident on the sensor
Implementation Method 2
broadband field probes, utilizing short dipole antennas formed by thin film resistive strips with diodes in series with the strips to convert RF to DC signals
Data Source
AI summary
In a stalk-type field probe, each of three resistive dipoles is formed with a resistive feedline on a common circuit board. Each circuit board comprises an elongated feedline section that extends through a cylindrical stalk, and a cross-arm that is disposed at a 54.7° angle relative to the elongation of the feedline section. The feedline sections are arranged to form an equilateral triangular prism, and the cross arms are arranged so that the dipole on each cross-arm is perpendicular to an imaginary plane to which the lines along which the elements of both of the other dipoles extend are parallel.