Two-Pin TR Switch with Off-Chip Inductor
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Solution Overview
Problem
Conventional radio frequency (RF) switch designs in wireless communication equipment face challenges due to the use of large, lossy on-chip inductors, which increase noise figure and insertion loss, and conflict with impedance matching and non-linear effect minimization requirements.
Innovation Solution
A two-pin TR switch architecture is implemented, where inductors are moved off-chip, and a switching component configures between transmit and receive modes using on-chip capacitors and inductors to optimize impedance matching and reduce noise figure, with all switches in a closed state during transmit mode and open state during receive mode, creating a resonant circuit for reduced insertion loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If on-chip inductors are used in conventional TR switch designs, then impedance matching between antenna and receiver section is achieved, but the inductors become large and lossy, increasing noise figure and insertion loss
Solution Approach 1:
The patent extracts the inductor from the on-chip integrated circuit and places it off-chip as an external component. This allows the on-chip area to be freed up while maintaining the impedance matching function through the external inductor connected to the antenna terminal, thereby reducing on-chip loss and noise figure while preserving impedance matching capability.
Solution Approach 2:
The patent moves the inductor from the two-dimensional on-chip plane to the three-dimensional space outside the chip. By placing the inductor off-chip and connecting it to the antenna terminal, the design achieves impedance matching without occupying valuable on-chip area, thus reducing parasitic effects and loss while maintaining the required electrical performance.
2Ease of manufacture
If on-chip inductors are used for impedance matching, then receiver section matching is optimized, but noise figure increases due to inductor losses
Solution Approach 1:
The patent extracts the lossy on-chip inductor and replaces it with an external inductor connected to the antenna terminal. This external inductor provides the necessary impedance matching for the receiver section without introducing the high losses and noise figure associated with on-chip spiral inductors, thereby optimizing receiver performance.
3Device complexity
If conventional one-pin TR switch is used, then simple switching function is achieved, but large on-chip inductors are required which take up chip space
Solution Approach 1:
The patent extracts the large on-chip inductor and places it off-chip as an external component connected to the antenna terminal. This extraction eliminates the need for large on-chip inductor areas while maintaining the simple one-pin TR switch functionality, thereby significantly reducing chip space occupation without compromising the switching function.
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 design reduces insertion loss and noise figure, while allowing independent optimization of transmit and receive signal paths, improving impedance matching and reducing electrical stress on switches.
Implementation Method 1
the capacitor and the off-chip inductor define a resonant circuit having a resonant frequency substantially equal to a frequency of a carrier signal of the transmitter stage
Data Source
AI summary
A two-pin transmit/receive switch design includes a switching component configured to selectively switch in elements for a transmit signal path and elements for a receive signal path. A capacitor in the transmit signal path may be switched out when receiving signals on the receive signal path. Being able to selectively switch out the capacitor allows the capacitor value to be selected for optimal operation during transmit mode. For example, insertion loss may be minimized. In addition, elements in the receive signal path may be optimized (e.g., impedance matching) without being affected by or affecting the optimization that was performed for the transmit signal path.