Frequency Separating Unit Matching Circuit Phase Shifter
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Solution Overview
Problem
Existing frequency separating units in portable mobile-radio devices face challenges in achieving space-saving designs with good isolation between signal paths and high ESD resistance.
Innovation Solution
A frequency separating unit with a matching circuit that includes a shunt arm to ground and a parallel circuit of an acoustic wave resonator and an impedance component, functioning as a phase shifter, is used between the antenna terminal and the band-pass filter, allowing for efficient phase shifting and energy dissipation to ground, thereby enhancing isolation and ESD resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a matching circuit with shunt arm to ground is used in the second signal path, then ESD resistance is improved, but device complexity increases
Solution Approach 1:
The patent combines the phase shifter function and ESD protection function into a single matching circuit structure. The shunt arm with impedance component serves dual purposes: providing the necessary phase shift for signal routing and simultaneously offering a discharge path for ESD events to ground, thereby reducing overall device complexity while maintaining both functions.
Solution Approach 2:
The matching circuit in the second signal path is designed to perform multiple functions simultaneously: it acts as a phase shifter for signal separation, provides ESD protection through the shunt arm to ground, and maintains impedance matching. This multi-functionality reduces the need for separate components, improving reliability without proportionally increasing complexity.
2Reliability
If a phase shifter is implemented in the matching circuit, then isolation between signal paths is improved, but area occupied increases
Solution Approach 1:
The patent merges the phase shifter functionality into the existing matching circuit structure rather than adding a separate phase shifter component. The matching circuit elements (shunt arm with impedance component) are configured to provide both impedance matching and the necessary phase shift, thereby achieving good isolation between signal paths without significantly increasing the occupied area.
Solution Approach 2:
The matching circuit is designed to perform multiple functions within a compact structure: impedance matching, phase shifting for signal separation, and ESD protection. By making the matching circuit multi-functional, the patent achieves good isolation between signal paths while minimizing the additional area occupied compared to using separate dedicated components for each function.
3Reliability
If the matching circuit is configured for phase shifting, then signal path isolation is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent achieves the required phase shift by optimizing the parameters of existing matching circuit elements (impedance values, positions) rather than requiring high-precision manufacturing of new components. The shunt arm impedance component is designed with specific parameter values that naturally provide the necessary phase shift, reducing sensitivity to manufacturing tolerances while maintaining good isolation between signal paths.
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 effective phase shifting, improved isolation between signal paths, and a compact design with high ESD resistance, suitable for applications like duplexers and diplexers in radio devices.
Implementation Method 1
The acoustic wave resonator comprises, in another variant, at least one acoustic wave transducer
Implementation Method 2
The acoustic wave resonator is, in one variant, a thin-film acoustic wave resonator
Data Source
AI summary
A frequency separating unit includes an antenna unit, a first signal path, a second signal path, first band-pass filter in the first signal path, a second band-pass filter in the second signal path, and a matching circuit between the antenna unit and the second band-pass filter in the second signal path. The matching circuit includes a shunt arm to ground that includes a first impedance component, and a parallel circuit that includes an acoustic wave resonator and a second impedance component. The matching circuit is configured to operate as a phase shifter and to produce a substantially open circuit at an input of the second filter in a pass band of the first band-pass filter.