Single Loop Antenna Frequency Agility via Switchable Capacitors
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Solution Overview
Problem
Previous universal transmitters for moveable barrier operators were expensive due to multiple tuned circuits, inefficient due to low Q-value circuits, and bulky due to metal loop antennas, limiting their ability to cover the entire frequency spectrum effectively, especially for small, low-power handheld transmitters.
Innovation Solution
A single, tuned loop antenna with adequate Q-values is used to transmit across a wide frequency range, utilizing a controller, synthesizer, and tuner to adjust the operational center frequency, allowing for narrow-band transmissions across the 300-434 MHz spectrum, with the antenna being small, lightweight, and powered by conventional batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple tuned circuits are used to transmit across different frequencies, then frequency coverage is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines multiple frequency transmission capabilities into a single tuned circuit by using a mechanical switch to connect different capacitor values to the same inductor, creating multiple resonant frequencies from one circuit topology rather than requiring separate circuits for each frequency
Solution Approach 2:
The single tuned circuit with switchable capacitors serves multiple frequency transmission functions that would traditionally require separate dedicated circuits, making the transmitter universal across different frequency bands while reducing overall circuit count
2Adaptability or versatility
If mechanical switches are used to switch between different transmitter circuits, then frequency switching capability is improved, but device complexity and potential reliability issues increase
Solution Approach 1:
The patent uses a mechanical switch to dynamically reconfigure the capacitor connections in the tuned circuit, allowing the same physical circuit to adapt its resonant frequency by changing its electrical configuration rather than requiring multiple static circuits
3Adaptability or versatility
If a single tuned circuit with low Q-value is used to cover wide frequency range, then frequency range coverage is improved, but transmission efficiency deteriorates
Solution Approach 1:
The patent changes the resonant frequency parameter of the single tuned circuit by switching between different capacitor values, allowing the circuit to be optimally tuned to each target frequency rather than operating at a fixed compromise frequency, thereby maintaining high Q-value efficiency across different frequency bands
4Adaptability or versatility
If a bulky metal loop antenna is used to achieve wide bandwidth, then frequency bandwidth is improved, but device weight and size increase
Solution Approach 1:
The patent makes the antenna electrically adjustable by incorporating a switchable capacitor that changes the resonant frequency of the loop antenna, allowing a compact physical structure to achieve wide frequency coverage through electrical reconfiguration rather than requiring a large physical antenna structure
5Ease of operation
If a single tuned circuit is used in small handheld transmitters, then portability is improved, but frequency coverage and efficiency deteriorate
Solution Approach 1:
The patent combines multiple frequency operation capabilities into the single tuned circuit of a compact handheld transmitter by using switchable capacitors, allowing portable size to be maintained while achieving wide frequency coverage through circuit reconfiguration rather than requiring multiple circuits or large antenna
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 efficient, portable, and cost-effective transmission across the entire frequency spectrum with high Q-values, maintaining a small size and low power consumption, while ensuring reliable operation of moveable barrier operators.
Implementation Method 1
A single loop antenna is tuned to match the first value of the operational center frequency and the single loop antenna operates across a second band of frequencies
Data Source
AI summary
A first value of an operational center frequency of a signal to transmit is determined according to received user input. The operational center frequency is centered within a first band of frequencies and the first band of frequencies has a first bandwidth. A single loop antenna is tuned to match the first value of the center frequency and the single loop antenna is arranged and configured to operate across a second band of frequencies having a second bandwidth. The first bandwidth is less than the second bandwidth. The signal is transmitted from the single loop antenna according to the first value of the operational center frequency to provide a transmitted signal.