Phased Array Antenna Feeding Using Resonant Transmission Lines
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Solution Overview
Problem
Existing phased array antenna feeding apparatuses are not suitable for miniaturization and monolithic integration in submicron IC technology due to their large size and requirement for high-quality RF switches, which are not readily available in baseline integrated technologies.
Innovation Solution
The apparatus uses at least two transmission lines operating as resonators with a quarter-wavelength electrical length, equipped with measuring positions and electronic circuits to detect and process signals, generating output signals for antenna elements, allowing for miniaturization and integration in submicron technology while minimizing RF losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a Butler matrix with transmission lines is used for beam steering, then beam direction control is achieved, but the apparatus size becomes large and miniaturization is difficult
Solution Approach 1:
The patent changes the fundamental operating parameters by using resonant transmission lines with specific electrical lengths (quarter-wavelength) instead of conventional transmission lines. This parameter change enables the apparatus to achieve the same beam steering function with significantly reduced physical dimensions, as the resonant structures can be miniaturized while maintaining their electromagnetic properties.
Solution Approach 2:
The patent transitions from a two-dimensional planar Butler matrix layout to a three-dimensional integrated circuit structure. By stacking multiple layers of transmission lines and using vertical interconnections, the apparatus achieves compact size in the planar dimensions while utilizing the third dimension (height) to accommodate the necessary electrical path lengths.
2Loss of energy
If high-quality RF switches are used in the Butler matrix, then RF losses are limited, but the device complexity increases and integration in baseline IC technology becomes difficult
Solution Approach 1:
The patent extracts and eliminates the complex RF switching mechanism from the Butler matrix structure. Instead of using switches to control signal paths, the invention uses fixed resonant transmission lines with predetermined electrical lengths to achieve phase control. This extraction of the switching function dramatically reduces device complexity and enables integration in baseline IC technology.
Solution Approach 2:
The patent replaces the mechanical/electronic switching system with a passive resonant structure system. The phase control previously achieved through dynamic switching is now achieved through the fixed resonant properties of the transmission lines, eliminating the need for complex switching mechanisms and reducing both device complexity and RF losses.
3Ease of operation
If transmission lines with half-wave length are used per antenna element, then beam steering is achieved, but the apparatus cannot be miniaturized
Solution Approach 1:
The patent changes the electrical length parameter of the transmission lines from half-wave to quarter-wave resonant lengths. This parameter change allows the transmission lines to achieve the necessary phase shift for beam steering while occupying only one-quarter of the wavelength in physical space, enabling miniaturization of the apparatus.
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
The solution enables high-resolution phase and amplitude control, efficient operation at high frequencies, and low noise, facilitating accurate calibration and efficient radiation pattern control for phased array antennas.
Implementation Method 1
at least two transmission lines or lumped circuits with similar transmission properties disposed in parallel and operated at a certain frequency as resonators
Implementation Method 2
the measured signals are a function of amplitude- and phase angle relations at the respective measuring position due to local energy concentrations stored in the resonators as standing wave
Data Source
AI summary
An apparatus (100) for feeding antenna elements of a phased array antenna, comprises: at least two transmission lines (101, 101) disposed in parallel and operated at a certain frequency as resonators, each of the transmission lines (101, 101) having a predetermined length dimensioned to be at least approximately an electrical quarter-wavelength of the operating frequency, a plurality of measuring positions provided on the transmission lines (101, 101) in spacings along the longitudinal direction (x) of the transmission lines, wherein each measuring position on one of the two transmission lines (101) faces directly a corresponding neighbored measuring position on the other transmission line (101) and such corresponding measuring positions being adjacent to each other in a direction transverse to the longitudinal direction of the transmission lines (101, 101) form a measuring position pair, respectively, wherein each of the circuits (110, 120, 130) detects and amplifies/attenuates the measuring signals from an assigned measuring position pair associated with the transmission lines (101, 101) for a corresponding longitudinal position as a function of a resonant field in the transmission lines at the respective positions, and further adds the measured and processed signals in order to generate output signals for feeding corresponding antenna elements.