Receive-Only Antenna Tuner Unit With Anti-Resonant Reactance Elements
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Solution Overview
Problem
Current antenna tuner units (ATUs) for mobile terminals are costly and inefficient due to their dual-purpose design, which requires large die sizes and high voltage handling capabilities, making them unsuitable for asymmetric data requirements in wireless communication systems, particularly in LTE-TDD systems where improved total isotropic sensitivity (TIS) is critical.
Innovation Solution
A receive-only antenna tuner unit with a radio frequency (RF) switch circuit featuring programmable capacitor arrays and anti-resonant reactance elements, which reduces the number of reactance elements needed, eliminating low impedance paths and allowing for dynamic tuning across multiple bands, thereby minimizing die size and cost while enhancing TIS.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dual-purpose ATU design is used to handle both transmit and receive paths, then voltage handling capability is improved, but device complexity and cost increase
Solution Approach 1:
The patent divides the ATU functionality into separate transmit and receive paths. The receive-only ATU is segmented from the transmit function, allowing each path to be optimized independently. The receive path uses simplified circuitry without the heavy-duty voltage handling components needed for transmit, reducing overall complexity while maintaining receive performance.
Solution Approach 2:
The patent extracts the receive function from the dual-purpose ATU design. By taking out only the receive path and eliminating the transmit path components, the design removes unnecessary voltage handling capability, cascode switches, and associated complexity, resulting in a simpler, more cost-effective receive-only solution.
2Reliability
If dual-purpose ATU design is used to handle both transmit and receive paths, then voltage handling capability is improved, but die size increases
Solution Approach 1:
The patent segments the ATU into receive-only functionality, eliminating the need for large-voltage-handling components such as multiple cascode switches and high-voltage MEMS switches. This segmentation allows the die size to be reduced significantly since only the minimal components needed for receive operation are included.
Solution Approach 2:
The patent extracts and removes the transmit path components from the integrated circuit, including the voltage handling infrastructure. By taking out only what is necessary for receive operation, the die area is minimized, avoiding the 3 mm² or larger die sizes required for dual-purpose ATUs.
3Ease of manufacture
If receive-only ATU design is used for asymmetric data requirements, then cost is reduced, but tuning range may be limited
Solution Approach 1:
The patent implements dynamic tuning capabilities using switchable capacitor arrays and variable reactance elements. These dynamic components allow the receive-only ATU to adapt its impedance matching across a broad frequency range, providing versatile tuning performance despite the simplified receive-only architecture and reduced cost.
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 provides a cost-effective, compact ATU with a broad tuning range, improving TIS and reducing die area requirements, thus addressing the limitations of existing dual-purpose ATUs in mobile terminals, especially in high-speed data downlink modes.
Implementation Method 1
anti-resonant reactance elements, one for each of the N number of reactance elements except for an Nth reactance element that is nearest to the RF input. Individual ones of the anti-resonant capacitive elements are coupled in parallel with a corresponding one of the N number of reactance elements to eliminate a low impedance path to a voltage node at a corresponding switch input
Implementation Method 2
The ATU further includes a capacitive element for each of the taps, wherein each capacitive element is coupled between a corresponding one of the taps and a voltage node
Data Source
AI summary
An antenna tuner unit (ATU) that provides broadband tuning is disclosed. The disclosed ATU includes a radio frequency (RF) switch circuit having an N number of switch inputs, wherein N is a natural number equal to 2 or greater. An N number of reactance elements are coupled in series between an RF input and one of the N number of switch inputs. Taps between adjacent pairs of the N number of reactance elements, wherein each of the taps is coupled to a corresponding one of the N number of switch inputs. The ATU further includes a capacitive element for each of the taps, wherein each capacitive element is coupled between a corresponding one of the taps and a voltage node. In at least one embodiment, each of the capacitive elements is made up of a programmable capacitor array.