RF Circuit Switching Layout for Harmonic Attenuation and Low Pass Band Loss
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Solution Overview
Problem
Existing radio frequency circuits experience increased pass band loss due to stringent harmonic attenuation requirements in matching circuits coupled to power amplifier circuits.
Innovation Solution
The radio frequency circuit is configured with a power amplifier circuit, harmonic attenuation circuit, matching circuit, and multiple switches to allow for selective routing of signals through or around the harmonic attenuation circuit based on harmonic attenuation requirements, reducing pass band loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a matching circuit with harmonic attenuation function is coupled to the output end of a power amplifier circuit, then harmonic attenuation is improved, but pass band loss increases
Solution Approach 1:
The matching circuit is divided into two separate circuits: a first matching circuit coupled to the power amplifier output, and a second matching circuit coupled to the antenna. The harmonic attenuation function is assigned to the second matching circuit only, allowing the first matching circuit to operate with minimal loss while the second circuit handles harmonic suppression.
Solution Approach 2:
The harmonic attenuation function is extracted from the first matching circuit and placed in the second matching circuit. This separation allows the first matching circuit to focus solely on impedance matching with minimal loss, while the second circuit provides harmonic attenuation without affecting the pass band performance of the first circuit.
2Object-generated harmful factors
If harmonic attenuation requirements are stringent, then harmonic suppression is improved, but pass band loss of radio frequency signals increases
Solution Approach 1:
The circuit configuration is made dynamic through the use of switches that can selectively connect different signal paths. The first switch can dynamically route signals either through the first matching circuit only or through both the first and second matching circuits, allowing adaptation to different harmonic attenuation requirements while minimizing pass band loss when high suppression is not needed.
Solution Approach 2:
Different parts of the system are assigned different functions: the first matching circuit provides impedance matching with minimal loss characteristics, while the second matching circuit provides harmonic attenuation. The switch configuration allows selective engagement of the second circuit's harmonic suppression function only when and where needed, rather than applying it uniformly across all operating conditions.
Data Source
AI summary
A radio frequency circuit include: a power amplifier circuit a harmonic attenuation circuit; a matching circuit; a filter; a first switch; a second switch; and a third switch. The matching circuit is coupled between the harmonic attenuation circuit and the power amplifier. The filter has an attenuation band including at least part of harmonic bands of a transmission band of a first band. The first switch is between the harmonic attenuation circuit and the filter. The second switch is between the filter and an antenna connection terminal. The third switch is between the matching circuit and the antenna connection terminal not via the harmonic attenuation circuit.