Variable Gain Antenna for Cellular Repeater RF Isolation
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Solution Overview
Problem
Cellular repeaters face challenges in maintaining signal strength and network performance due to the need for RF isolation between directional antennas, which can lead to suboptimal signal levels and excess loss when not aligned with the base station, degrading network performance.
Innovation Solution
Implementing variable-gain directional antennas with a multi-stage array of patch antennas and an RF switch to maximize RF isolation between the donor and server antennas, with adaptive gain settings based on signal strength measurements to ensure optimal communication without impairing repeater performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If directional antennas are used to provide RF isolation between donor and server antennas, then RF isolation is improved, but signal strength is degraded when the antenna is not aligned with the base station
Solution Approach 1:
The patent applies the dynamics principle by making the antenna system adjustable through multiple gain stages. The antenna can dynamically change its radiation pattern from highly directional to more omnidirectional by switching between different gain stages, allowing it to adapt to changing alignment conditions with base stations while maintaining RF isolation when needed.
Solution Approach 2:
The patent implements parameter changes by varying the gain of the antenna through a multi-stage amplifier system. Each stage can be independently controlled to change the overall gain parameter, transforming the antenna's radiation characteristics from highly directional (high gain) to more omnidirectional (lower gain) to optimize signal reception under different conditions.
2Object-affected harmful factors
If physical separation between donor and server antennas is increased to achieve RF isolation, then RF isolation is improved, but device complexity and space requirements increase
Solution Approach 1:
The patent changes the gain parameter of the antennas to achieve RF isolation without requiring large physical separations. By adjusting the gain and directional characteristics through the multi-stage amplifier system, the antennas can provide sufficient isolation in compact configurations, reducing the need for extensive physical separation.
Solution Approach 2:
The dynamic adjustability of the antenna gain allows the system to optimize RF isolation performance within limited physical space. The ability to switch between different gain stages enables the antenna to adapt its radiation pattern to maximize isolation from the other antenna in the enclosure, eliminating the need for large physical separations.
3Reliability
If high gain directional antennas are used to maximize signal reception, then signal strength is improved, but RF isolation between antennas is reduced
Solution Approach 1:
The patent uses the dynamics principle by implementing a multi-stage amplifier system where each stage can be independently controlled. This allows the antenna to dynamically adjust its gain and radiation pattern, switching between high gain (directional) mode for maximum signal reception and lower gain mode for improved RF isolation, depending on the operational requirements.
Solution Approach 2:
The system changes the gain parameter through the multi-stage amplifier, allowing transformation of the antenna's radiation characteristics. By varying the gain parameter, the antenna can optimize between signal strength and RF isolation performance, adapting to different operational conditions without being fixed at a single gain level.
Data Source
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AI summary
A cellular repeater (100) and method of operating a cellular repeater are disclosed. The cellular repeater (100) includes a variable-gain donor antenna (102) adapted to communicate with a base station (104) and a variable-gain server antenna (106) adapted to communicate with a mobile device (108). A signal from a selected base station selected from one or more available base stations that are available to the cellular repeater is measured at the donor antenna. The gain of the donor antenna is adapted to maximize a signal level of the signal received at the donor antenna from the selected base station. A calibration signal from the server antenna is measured at the donor antenna to determine a radio frequency isolation between the donor antenna and the server antenna. The gain of the server antenna is adapted to maximize the radio frequency isolation between the donor antenna and server antenna.