Antenna Matching Network Tuning Across TDD Settling Gaps
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Solution Overview
Problem
Tunable components in impedance matching circuits, such as barium strontium titanate (BST) capacitors, exhibit settling times that are significantly longer than the gaps between downlink and uplink transmissions in time division duplex (TDD) communication systems, leading to phase and amplitude disturbances in signals, which can introduce noise and degrade RF performance.
Innovation Solution
The solution involves changing the tuning value of tunable components in multiple stages during non-contiguous transitions between transmission states, allowing the components to settle before the next transmission, thereby minimizing impedance changes during active communication periods and maintaining constant values during active transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tunable components are used to achieve impedance matching, then RF performance is improved, but settling time becomes excessively long causing phase and amplitude disturbances
Solution Approach 1:
The patent divides the single large tuning adjustment into multiple smaller incremental adjustments. The tunable component undergoes a series of staged transitions from the initial tuning value to the target tuning value, with each transition being small enough to complete within the available gap time, thereby resolving the contradiction between achieving the desired impedance match and doing so within the limited time available.
2Adaptability or versatility
If tuning value changes are made during transmission gaps, then impedance matching is updated, but phase and amplitude disturbances occur if the component does not settle before next transmission
Solution Approach 1:
The patent performs preliminary actions by initiating the tuning adjustment process at the beginning of the transmission gap, allowing the tunable component to start settling before the next transmission begins. By planning and executing the tuning change in advance during the available gap time, the system ensures the component has sufficient time to stabilize before signal transmission resumes, preventing phase and amplitude disturbances.
3Loss of time
If multiple staged transitions are implemented, then settling time is reduced, but device complexity increases
Solution Approach 1:
The patent implements periodic action by using the recurring transmission gaps as opportunities to perform incremental tuning adjustments. Each transmission gap provides a periodic opportunity to advance the tuning value closer to the target, breaking down the complex multi-stage transition into simple, repetitive steps that leverage the existing periodic structure of TDD transmissions rather than adding complex continuous control mechanisms.
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 degradation by ensuring that tunable components settle before the next transmission, enhancing the performance of RF front-end components by preventing phase and amplitude disturbances, thus improving the overall quality of the communication system.
Implementation Method 1
Many impedance matching circuits incorporate tunable components, such as barium strontium titanate (BST) tunable capacitors
Implementation Method 2
the tunable components may take on the order of at least 100 microseconds in terms of a settling time associated with a transition from a first/initial state/value to a commanded, second/final state/value (due to the resistive-capacitive (RC) load represented by the tunable capacitor, and the RC time constant associated therewith)
Data Source
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AI summary
Aspects of the subject disclosure may include, for example, changing a tuning value of a tunable component coupled to an antenna from a first tuning value to a second tuning value during a first stage, and changing the tuning value of the tunable component from the second tuning value to a third tuning value during a second stage that occurs subsequent to the first stage, wherein during each of the first stage and the second stage the antenna is not utilized by a transmitter for communication purposes, wherein the first stage and the second stage are separated from one another by a first active region, and wherein during the first active region the transmitter causes a first signal to be transmitted from the antenna for communication purposes. Other embodiments are disclosed.