Distributed RF Channel Emulator for Spatial Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current RF channel emulators face limitations in producing a correlated spatial distribution within the test volume due to physical constraints, such as antenna size and frequency, leading to increased antenna numbers, amplifier, and channel emulator resources, which result in high power amplification requirements, significant signal loss, and increased costs, especially as frequency and test volume size increase.
Innovation Solution
A distributed channel emulation system is implemented, where the spatial channel emulator components are distributed between a central location and a remote location near the antennas, using intermediate frequency or baseband signals to minimize losses, allowing for lower loss cables and reduced power amplification needs, while maintaining effective channel emulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the number of antennas and amplifiers is increased to produce correlated spatial distribution at higher frequencies, then the spatial distribution quality is improved, but the power amplification requirements and costs increase significantly
Solution Approach 1:
The system divides the boundary array into multiple distributed nodes, each independently generating and transmitting signals. This segmentation allows each node to operate at lower power levels while collectively achieving the desired spatial distribution through coordinated transmission, thereby reducing individual amplifier power requirements and overall system complexity.
Solution Approach 2:
The patent transitions from traditional RF-domain signal distribution to baseband or intermediate frequency domain distribution. By performing signal processing at lower frequencies and converting to RF only at the antenna nodes, the system achieves correlated spatial distribution without requiring high-power amplifiers throughout the entire signal path, thus reducing power requirements while maintaining spatial quality.
2Reliability
If traditional RF cables are used to connect channel emulators to antennas, then signal transmission is achieved, but significant signal loss occurs especially at higher frequencies
Solution Approach 1:
The system replaces traditional RF cable connections with wireless or alternative low-loss transmission methods between the channel emulators and antennas. By eliminating long RF cable runs that cause significant attenuation, particularly at millimeter-wave frequencies, the system maintains signal integrity and reduces energy loss while ensuring reliable signal transmission.
Solution Approach 2:
The patent changes the frequency parameter of signal transmission by operating channel emulators at baseband or intermediate frequencies rather than directly at RF. This parameter change reduces signal loss during transmission since lower frequencies experience less attenuation in cables and through air, thereby improving reliability while minimizing energy loss.
3Adaptability or versatility
If more channel emulator resources are deployed to support higher frequencies, then frequency coverage is improved, but the system cost increases
Solution Approach 1:
The system employs channel emulators that can operate across multiple frequency ranges by implementing software-defined radio architecture. This multi-functionality allows the same hardware resources to support various frequencies including millimeter-waves, thereby improving frequency coverage without proportionally increasing system cost, as the emulators can be reconfigured for different frequency bands.
Solution Approach 2:
The patent uses multiple distributed nodes that each contain simplified channel emulator functionality. Rather than requiring one complex centralized emulator for each frequency, the system distributes simplified emulator instances across multiple nodes, achieving broad frequency coverage through coordinated operation of simpler, more cost-effective units.
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 signal loss, minimizes the need for high-power amplifiers, and decreases costs by using lower loss cables and existing RF channel emulators to support higher frequencies, enhancing the efficiency and scalability of RF testing systems.
Implementation Method 1
an up-converter configured to receive a local oscillator, LO, signal and to mix the LO signal with an impaired signal of the emulated channel to produce a radio frequency, RF, signal
Implementation Method 2
a down-converter configured to mix a local oscillator, LO, signal with an RF signal to down convert the RF signal to a baseband or intermediate frequency, IF, signal
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A method and system for measuring a device under test (22) are disclosed. In some embodiments, a system includes, at a central location (64) exterior to a test chamber (65), an emulator core (70) configured to introduce an impairment in each of at least one of a received signal and a transmit signal to produce a digital impaired signal, and at a remote location interior to the test chamber (65) for each of a plurality of antennas (12) in communication with a device under test (DUT) (22), at least one of a transmitter (83) configured to convert the digital impaired signal to an analog RF signal and a receiver (93) configured to convert a received analog RF signal to a received signal to be impaired by the emulator core (70) to produce the impaired signal.