RF Antenna Data Link Using Variable Rate Signaling for EMI Control
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Solution Overview
Problem
Conventional RF communications systems face challenges with electromagnetic interference (EMI) and manufacturing complexity due to the use of costly, complex coaxial cables for data transmission at high data rates.
Innovation Solution
A radio frequency antenna system with a high-speed digital link that digitizes RF signals and applies them at a variable data rate, distributing signal energy over multiple frequency bands to alter the EMI spectral profile, using unshielded conductors and a dual-clocked RF transceiver to minimize EMI and synchronize data rates between clock domains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If coaxial cables are used to transmit data signals between RF radio circuits and base band circuits, then electromagnetic interference (EMI) is reduced, but manufacturing complexity and cost increase
Solution Approach 1:
The patent extracts the EMI-shielding function from the cable structure itself by using unshielded conductors combined with spread spectrum clocking technology. Instead of relying on physical shielding (coaxial cable), the solution removes the shielding requirement and achieves EMI reduction through signal processing - specifically by spreading the clock signal energy across a wide frequency spectrum, which minimizes concentrated EMI emissions.
Solution Approach 2:
The patent changes the temporal and spectral parameters of the clock signal from a fixed frequency to a spread spectrum variable frequency. By varying the clock frequency dynamically across a range of frequencies, the signal energy is distributed over a wider bandwidth, reducing peak EMI emissions at any single frequency and allowing the use of simpler unshielded conductors.
2Object-affected harmful factors
If coaxial cables are used to transmit data signals, then electromagnetic interference (EMI) is reduced, but cost increases
Solution Approach 1:
The patent replaces expensive coaxial cables with inexpensive unshielded conductors. The cost savings are achieved by using simple, readily available conductor materials without the need for complex coaxial cable construction, shielding layers, and specialized connectors. The unshielded conductors can be implemented as simple PCB traces or basic wire connections, dramatically reducing material and manufacturing costs.
3Device complexity
If unshielded conductors are used to transmit data signals, then manufacturing complexity is reduced, but electromagnetic interference (EMI) increases
Solution Approach 1:
The patent introduces spread spectrum clocking as an intermediary mechanism between the digital data signals and the transmission medium. This intermediary process transforms the clock signal characteristics before transmission, spreading the energy spectrum to reduce EMI. The spread spectrum technique acts as a mediator that allows unshielded conductors to transmit signals without generating excessive EMI, bridging the gap between simple transmission media and EMI requirements.
4Ease of operation
If fixed clock frequency is used for data transmission, then data rate synchronization is simplified, but electromagnetic interference (EMI) spectral density increases
Solution Approach 1:
The patent transitions from a static fixed clock frequency to a dynamic spread spectrum clock frequency that varies over time. The clock frequency is modulated to spread across a range of frequencies, creating a dynamic signaling scheme. This dynamic approach distributes the EMI energy across a wider spectrum, reducing peak spectral density while maintaining data integrity through appropriate receiver synchronization techniques.
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 approach reduces EMI and manufacturing complexity by using less costly, less complex unshielded conductors while maintaining continuous data transfers and compliance with EMI emission masks, with minimal cable losses and reduced spurious noise.
Implementation Method 1
The variable data rate distributes the signal energy of the digitized data signals over one or more bands of frequencies, thereby beneficially altering an EMI spectral profile
Data Source
AI summary
A radio frequency antenna system and high-speed digital data link are disclosed to, among other things, reduce electromagnetic interference (“EMI”) at relatively high data rates while reducing the manufacturing complexities associated with conventional data links. In one embodiment, a radio frequency (“RF”) antenna system includes an antenna and an RF radio coupled to the antenna for receiving wireless RF signals. In particular, the RF radio is configured to digitize RF signals at a fixed data rate to form digitized data signals and to apply the digitized data signals at a variable data rate to a high-speed digital link. The variable data rate distributes the signal energy of the digitized data signals over one or more bands of frequencies, thereby beneficially altering an EMI spectral profile describing emissions that develop as the digitized data signals are transported through a channel.